 Section 14 of the Romance of Modern Mechanism. This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org. Recording by Tina Ding. The Romance of Modern Mechanism by Archbaugh Williams. Chapter 12, The Machinery of a Ship. Part 1. The reversing engine, marine engine speed governors, the steering engine, blowing and ventilating apparatus, pumps, feed heaters, feed water filters, distillers. With many travelers by sea, the first impulse after bunks have been visited and baggage has been safely stored away, is to saunter off to the hatches over the engine room and peer down into the shining machinery which forms the heart of the vessel. Some engine is sure to be at work to remind them of the great powers stored down there below and to give a foretaste of what to expect when the engine room gone sounds and the men in charge opens the huge throttle controlling some thousands of horsepower. By craning forward over the edge of the ship, a jet of water may be seen spurting from a hole in the side just above the water line denoting either that a pump is emptying the bilge or that the condensers are being cooled ready for the work before them. Towards the forecastle, a busy little donkey engine is lifting bunches of luggage off the key by means of a rope passing over a swinging spar attached to the mast and lowering it into the nether regions where stevedores pack it neatly away. In a small compartment on the upper deck is some mysterious and not very important looking gear yet as it operates the rudder it claims a place of honor equaling that of the main engines which turn the screw. To the ordinary passenger the very existence of much other machinery the reversing engines the air pumps the condensers the feed heaters the filters the evaporators and refrigerators and the ventilators is most probably unsuspected. The electric light he would from his experience of things assure vaguely connect with an engine somewhere but the apparatus referred to either works so obtrusively or is so sequestered from the public eye that one might travel for weeks without even hearing mention of it. On the worship the amount of machinery is vastly increased in fact every war vessel from the first class battleship to the smallest destroyer is practically a conjuries of machines accommodation for human beings taking a very secondary place. Big guns must be trained fad and cleaned by machinery and these processes simple as they may sound need most elaborate devices. The difference in respect of mechanism between the King Edward Seventh and Nelson's victory is as great as that between a motor car and a farmer's cart. It would not be too much to say that the mechanical knowledge of any period is very adequately gauged from its fighting vessels. During the last 20 years marine engines have been enormously improved but the advance of auxiliary appliances has been even more marked. In earlier times the matter considered of primary importance was the propulsion of the vessel and engineers turned their attention to the problem of crowding the greatest possible amount of power into the least possible amount of space. This was affected mainly by the compounding of engines using the steam over and over again in cylinders of increasing size and by improving the design of boilers. As soon as this business had been well forwarded auxiliary machinery which though not absolutely necessary for movement greatly affected the ease, comfort and economy of working a ship got its share of notice with the result that a tour around the works of a modern battleship or liner is a growing wonder and a liberal education in itself. This chapter will deal with the auxiliaries to be found in large vessels designed for peaceful or warlike uses. Many devices are common to ships of both classes and some are confined to one type only though the steel wall certainly has the advantage with regard to multiplicity. We may begin with the reversing engine. All marine engines should be fitted with some apparatus which enables the engineer to reverse them from full speed ahead to full speed a stern in a few seconds. The effort required to perform the operation of shifting over the valves is such as to necessitate the help of steam. Therefore, you will find a special device in the engine room which when the engineer moves a small lever either way from the normal position lets steam into a cylinder and moves rods reversing the main engine. By a link action which could not be explained without a special diagram the valves of the auxiliary will closed automatically as soon as the task has been performed so that there is no constant pressure on the one or the other side of its piston. To prevent the reversing being too sudden the auxiliaries piston rod is prolonged and fitted to a second piston working in a second cylinder full of glycerin or oil. This piston is pierced with a small hole through which the incompressible liquid passes as the piston moves. Since its passage is gradual the engines are reversed deliberately enough to protect their valves from any severe strains. These reversing engines can if the steam serving them fails be worked by hand. The marine engine speed governors. When a ship is passing through a strong sea and pitches as she crosses the waves the screw is from time to time lifted clear of the water and the engines which a moment before have been doing their utmost suddenly find their load taken off them. The result is raising of the machinery which makes itself very emplacently felt from one end of the ship to the other. Then the screw revolving at a speed much above the normal suddenly plunges into the water again and encounters great resistance to its revolution. A series of changes from full to no load as engineers termed it must be harmful to any engines even though the evil effects are not shown at once. Great strains are set up which shake bolts loose or may crack the heavy standards in which the cranks and shaft work and even seriously tax the shaft itself and the screw. On land every stationary engine set to do tasks in which the load varies which practically means all stationary engines are fitted with a governor to cut off the steam directly. A certain rate of revolution is exceeded. These engines are the more easily governed because they carry heavy flywheels which pick up or lose their velocity gradually. A marine engine on the other hand has only the screw to study it and this is extremely light in proportion to the power which drives it. In fact has scarcely any controlling influence at all as soon as it leaves the water. Marine engineers therefore need some mechanical means of restraining their engines from running away. The device must be very sensitive and quick acting since the engines would increase their rate threefold in a second if left ungoverned when running free while on the other hand it must not throttle the steam supply a moment after the work has begun again when the screw takes the water. Many mechanisms have been invented to curb the marine engine. Some have proved fairly successful others practically useless and the fact remains that owing to the greater difficulty of the task marine governing is not so delicate as that of land engines. A great number of steamships are not fitted with governors for the simple reason that the engineers are skeptical about such devices as a class and would rather not be bothered with them. But whatever may have been its record in the past the marine governor is at the present time sufficiently developed to form an item in the engine rooms of many of our largest ships. We select as one of the best devices yet produced that known as Andrew's patent governor and append a short description. It consists of two main parts the pumps and the ram closing the throttle. The pumps to a number are worked alternately by some moving part of the engine such as the air pump lever. They inject water through a small pipe into a cylinder the piston rod of which operates a throttle valve in the main steam supply to the engines. At the bottom of this cylinder is a bypass or artificial leak through which the water flows back to the pumps the size of the flow through the bypass is controlled by a screw adjustment. We will suppose that the governor is set to permit 100 revolutions a minute as long as that rate is not exceeded the bypass will let out as much water as the pumps can inject into the cylinder and the piston is not moved. But as soon as the engines begin to race the pumps send in an excess and the piston immediately begins to rise closing the throttle. As the speed falls the leak gets the upper hand again and the piston is pushed down by a powerful spring opening the throttle. It might be supposed that when the screw races the pumps will not only close the throttle but also press so hard on it as to cause damage to some part of the apparatus before the speed have fallen again. This is prevented by the presence of a second control valve or leak worked by a connecting rod rising along with the piston rod of the ramp. The two rods are held in engagement by a powerful spring which presses them together so that a hollow in the first engages with a projection on the second. Immediately the pressure increases and the piston rises. The second valve is shut by the lifting of its rod and so father augments the pressure in the cylinder and quickens the closing of the throttle valve. This pressure increase must however be checked or the piston would overrun and stop the engines. So when the piston has nearly finished its stroke the connecting rod comes into contact with a stop which disengages it from the piston rod and allows the second control valve to be fully opened by the spring pulling on its rod. The piston at once sinks to such a position as the pressure allows and the action is repeated time after time. The governing is practically instantaneous though without shock and is set to keep the engine within 3% of the normal rate. That is if 100 be the proper number of revolutions it would not be allowed to exceed 103 or drop below 97. Such governing is in technical language very close. The idea is very ingenious. Pumps working against a leak and as soon as they have mastered it being aided by a secondary valve which reduces the size of the leak so as to render the effect of the pumps increasingly rapid until the throttle has been closed. Then the secondary valve is suddenly thrown out of action gives the leak full play and causes the throttle to open quickly so that the steam may be cut off only for a moment. By the turning of a small milled screw head a couple of inches in diameter the pace of 5000 horsepower engines is as fully regulated as if a powerful break were applied the moment they exceeded the legal limit. Steering engines. The uninitiated may think that the men on the bridge revolving a spoke wheel with apparently small exertion is directly moving the rudder to port or to starboard as he wishes but the helm of a large vessel traveling at high speed could not be so easily deflected were not some giant at work down below in obedience to the easy motions of the wheel. Sometimes in the special little cabin on deck but more often in the engine room where it can be tended by the staff there is the steering engine usually worked by steam power. Two little cylinders turned a warm screw which revolves a warm wheel and a train of cocks the last of which moves to right or left a quadrant attached to the chains or cables which work the rudder all that the steersman has to do with his wheel is to put the engine in forward backward or middle gear. The steam being admitted to the cylinders quickly moves the helm to the position required. A particularly ingenious steam gear is that made by Messers-Hartfield and Company of London. Its chief feature is the arrangement whereby the power to move the rudder into any position remains constant. If you have ever steered a boat you will remember that when a sudden curve must be made you have to put far more strength into the tiller than would suffice for a slight change of direction. Now, if a steam engine and gear were so built as to give sufficient pressure on the helm in all positions it would, if powerful enough to put the ship heart apart evidently be overpowered for the gentler movements and would waste steam. The Hartfield gear has the last of the cock train the one which engages with the rack operating the tiller mounted eccentrically. The rack itself is not part of a circle but almost flat centrally and sharply bent at the ends. In short, the curve is such that the rack teeth engage with the eccentric cog at all points of the latter's revolution. When the helm is normal the longest radius of the eccentric is turned towards the rack. In this position it exerts least power but least power is then needed. As the helm goes over the radius of the cocks gradually decreases and its leverage proportionately increases so that the engine is taxed uniformly all the time. Some more vessels including the ill-fated Russian cruiser Varieg have been fitted with electric steering gear operated by a motor in which the direction of the current can be varied at the wheel of the helmsman. All power gears are so arranged that in case of a breakdown of the power a hand wheel can be quickly brought into play. Flowing and ventilating apparatus A railway locomotive sends the exhaust steam up the funnel with sufficient force to expel all air from the same end to create a vacuum. The only passage for the air flying to fill this empty space lies through the firebox and tubes traversing the boiler from end to end. Were it not for the induced drought the invention of George Stevenson no locomotive would be able to draw a train at a higher speed than a few miles an hour. On shipboard the fresh water used in the boilers is far too precious to be wasted by using it as a fire exciter. Salt water to make good the loss would soon corrode the boilers and cause terrible explosions. Therefore the necessary drought is created by forcing air through the furnaces instead of by drawing it. The stoke hold is entirely separated from the outer air except for the ventilators down which air is forced by centrifugal pumps at considerable pressure. This drought serves two purposes. It lowers the temperature of the stoke hold which otherwise would be unbearable and also feeds the fires with plenty of oxygen. The air forced in can escape in one way only this by passing through the furnaces. When the ship is slowed down the forced drought is turned off and then you see the poor stokers coming up for a breath of fresh air. In the Red Sea or other tropical latitudes these grimy but useful men have a very hard time of it. While passengers up above are grumbling at the heat the stoker below is almost fainting although clad in nothing but the thinnest of trousers. In the engine room also things at times become uncomfortably warm. Take the case of the United States Monitor and for Trity which went into commission in 1895 for a trial run. Both stoke hold and engine room were very insufficiently ventilated. The vessel started from Hampton roads for Brunswick Georgia The trip of about 500 miles occupied five days in the latter part of July and for sheer suffering has perhaps seldom been equaled in our naval history. The fire room stoke hold temperature was never below 150 degrees and often above 170 degrees while the engine room ranged closely about 150 degrees. For the first 24 hours the men stood at well but on the second day seven succumbed to the heat and were put on the sick list one of them nearly dying. Before the voyage was ended 28 had been driven to seek medical attendance. The gaps thus created were partially filled with inexperienced men from the deck force until there was only a lifeboat's crew left in each watch. On the evening of the fourth day out our men had literally fought the fire to a finish and had been vanquished. The watch on duty broke down one by one and the engines after lumbering along slower and slower actually stopped for want of steam. At daybreak the next morning we got underway and steamed at a very conservative rate to our destination. Fortunately only about 10 miles distant the scene in the fire room that morning was not of this earth and far beyond description. The heat was almost destructive to life steam was blowing from many defective joints and water columns tools ladders doors and all fittings were too hot to touch and the place was dense with smoke escaping from furnace doors for there was absolutely no drought. The man collected to build up the fires were the best of those remaining fit for duty but they were worn out physically were nervous apprehensive and dispirited. Rough Irish firemen who would stand in a fair fight till killed in their tracks were crying like children and begging to be allowed to go on deck so completely were they amend by the cruel ordeal they had endured so long. How a float is a nautical figure of speech often idly used but then we saw it for months thereafter the ship was actively employed on the southern coast drilling militia at different ports and sweltering in the new dock at Port Royal. One trip of 29 hours broke the record for heat the fire room being frequently above 180 degrees all fire room temperatures were taken in the actual spaces where the man had to work and not from hot corners or overhead pockets. The ventilators were subsequently altered and the men enjoyed comparative comfort. The words quoted will suffice to establish the importance of a proper current of air where men have to work. One of the greatest difficulties encountered in deep mining is that while the temperature approaches and sometimes passes that of a stoke code the task of sending down a cool current from above is with depths of 4000 feet and over a very awkward one to carry out. On passengerships the fans ventilating the cabins and saloons are constantly at work either sucking out foul air or driving in fresh. The principle of the fan is very similar to that of the centrifugal water pump veins rotating in a case open at the center through which the air enters to be flung by the blades against the sides of the case and driven out of an opening in its circumference. Sometimes an ordinary screw-shaped fan such as we often see in public buildings is employed. Pumps every steamship carries several varieties of pump. First there are the large pumps generally of a simple type for emptying the build or any compartment of the ship which may have sprung a leak. All hands to the pumps is now seldom heard on a steamer for the opening of a steam cock sets machinery in motion which will successfully fight any but a very severe breach. It is needless to say that these pumps form a very important part of a ship's equipment without which many a fine vessel would have sunk which has struggled to land. The pumps for the condensers form another class. These are centrifugal force pumps. Their duty is to circulate code-seat water around the nests of tubes through which steam flows after passing through the cylinders. It is thus converted once more into water ready for use again in the boiler. Every atom of the water is evaporated, condensed, and pumped back into the boiler once in a period ranging from 15 minutes to an hour according to the type of boiler and the size of the supply tanks. Some condensers have the cooling water passed through the tubes and the steam circulated around these in an airtight chamber. In any case, the condenser should be so designed as to offer a large amount of cold surface to the hot vapor. A breakdown of the condenser pumps is a serious mishap since steam would then be wasted which represents so much fresh water hard to replace in an open sea. It would be comparable to the disarrangement of the circulating pump on the motor car though the effects are different. We must not forget the feed pumps for the boilers. On their efficient action depends the safety of the ship and her passengers. Water must be maintained at a certain level in the boiler so that all tubes and other services in direct contact with the furnace gases may be covered. The disastrous explosions we sometimes hear of are often caused by the failure of a pump, the burning of a tube or a plate and the inevitable collapse of the same. The firms of Weir and Worthington are among the best known makers of the special high-pressure pumps used for throwing large quantities of water into the boilers of mercantile and war vessels. Feed heaters. As the fuel supply of a vessel cannot easily be replenished on the high seas, economy in cold consumption is very desirable. If you put a cold spoon into a boiling saucepan, evolution is checked at once, though only for a moment while the spoon takes in the temperature of the water. Similarly, if cold water be fed into a boiler, the steam pressure at once falls. Therefore, the hotter the feed water is, the better. The feed heater is the reverse of the condenser. In the latter, cold water is used to cool hot steam. In the former, hot steam to heat cold water. There are many patterns of heaters. One type, largely used, sprays the cold water through a valve into a chamber through which steam is passed from the engines. The spray falling through the hot vapor partially condenses it and takes up some of its heat. The surplus steam travels onto the condensers. A float in the lower part of the chamber governs a valve admitting steam to the boiler pumps so that as soon as a certain amount of water has accumulated, the pumps are started and the hot liquid is forced into the boiler. Another type, the hamsen feeder, sends steam through pipes of a wavy form surrounded by the feed water, there being no actual contact between liquid and vapor. An ally of the heater is the feed water filter which removes suspended matter which if it entered the boiler would form a deposit around the tubes and while decreasing their efficiency make them more liable to burning. The most dangerous element caught by the filters is fatty matter, oil which has entered the cylinders and being carried off by the exhaust steam. The filter is either high pressure that is situated between the pump and the boiler or low pressure that is between the pump and the reservoir from which it draws its water. The second class must have large areas so as not to throttle the supply unduly. Many kinds of filtering media have been tried, fabrics of silk, calico, coconut fiber, toweling, sawdust, cork dust, charcoal, coke but the ideal substance at once cheap, easily obtainable, durable and completely effective yet remains to be found. A filter should be so constructed that the filtering substance is very accessible for cleansing or renewal. Distillers, we now come to a part of a ship's plant very necessary for both machines and human beings. Many a time have people been in the position of the ancient mariner who exclaimed, water, water, everywhere but not a drop to drink. Water is so weighty that a ship cannot carry more than a very limited quantity and that for the immediate needs of her passengers. The boilers, in spite of their condensers, waste a good deal of steam at safety valves through leaking joints and packings and in other ways. This loss must be made good for, as already remarked, salt water spells the speedy ruin of any boiler it enters. The distiller in its simplest form combines a boiler for changing water into vapor with a condenser for reconverting it to liquid. Solids in impure water do not pass off with a steam so that the latter, if condensed in clean vessels, is fit for drinking or for use in the engine boilers. A pound of steam will, under the system, give a pound of water. But as such procedure would be extravagant of fuel, compound condensers are used, which act in the following manner. High-pressure steam is passed from the engine boilers into the tubes of an evaporator and converts the salt water surrounding it into steam. The boiler steam then travels into its own condenser or into the feed water heater. While the steam it generated passes into the coils of a second evaporator, converts water there into steam and itself goes to a condenser. The steam generated in the second evaporator does similar duty in a third evaporator so that one pound of high-pressure steam is directly reconverted to water and also indirectly produces between two and three pounds of fresh water. The condensers used are similar to those already described in connection with the engines and need no further comment. About the evaporators, it may be said that they are so constructed that they can be cleaned out easily as soon as the accumulation of salt and other matter renders the operation necessary. Usually one side is hinged and provided with a number of bolts all around the edges which are quickly removed and replaced. The United States Navy includes a ship, the Iris, whose sole duty is to supply the fleet she attends with plenty of fresh water. She was built in 1885 by Messrs R. and W. Hawthorne of Newcastle-on-Tin and measures 310 feet in length, 38.5 feet beam. For her size, she has remarkable bunker capacity and can accommodate nearly 2,500 tons of coal. Four and aft are huge storage tanks to hold between them about 170,000 gallons of fresh water. Her stills can produce a maximum of 60,000 gallons a day. It has been reckoned that each ton of water distilled costs only 18 cents or stated otherwise that 40 gallons cost one penny. At many ports, fresh water costs three or four times this figure and even when procured is of doubtful purity. During the Spanish-American War, the Iris and sister ship, the Rainbow, proved most useful. End of section 14. Section 15 of the Romance of Modern Mechanism. This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org. Recording by Tina Ding, The Romance of Modern Mechanism by Arch Bald Williams. Chapter 12, The Machinery of a Ship, Part 2. Refrigerators, The Search Light, Wireless Telegraphy Instruments, Safety Devices, The Transmission of Power on a Ship. Refrigerators, Of late years, the frozen meat trade has increased by leaps and bounds. Australia, New Zealand, Argentina, Canada, and the United States send millions of pounds worth of mutton and beef across the water every year to help feed the populations of England and Europe. In past times, the live animals were sent to be either killed when disembarked or fed it up for the market. This practice was expensive and attended by much suffering of the unfortunate creatures if bet whether knocked the vessel about. Refrigerating machinery has altered the traffic most fundamentally. Not only can more meat be sent at lower rates, but the variety is increased and many other substances than flesh are often found in the cold stores of a ship. Water and fruit being important items. Certain steamship lines, such as the Shaw, Saville, and Albion, plying between England and Australia, include vessels specially built for the transport of vast numbers of carcasses. Upwards of a million carcasses have been packed into the hull of a single ship and capped perfectly fresh during the long six weeks voyage across the equator. Every passenger carrying steamer is provided with refrigerating rooms for the storage of perishable provisions. And as the comfort of the passengers, not to say their luxury, is bound up with these compartments, it will be interesting to glance at the method employed for creating local frost amid surrounding heat. The big principle underlying the refrigerator is this, that a liquid when turned into gas absorbs heat, thus to convert water into steam, you must feed it with heat from a fire. And that as soon as the gas loses a certain amount of its heat, it reverts to liquid form. Now, take ammonia gas. The spirits of the hearts horn we buy at the chemists is water impregnated with this gas. At ordinary living temperatures, the water gives out the gas as a sniff at the bottle proves in a most effective manner. If this gas were cooled to 37.3 degrees below zero, it would assume a liquid state, that is that temperature marks its boiling point. Similarly, steam cooled to 212 degrees Fahrenheit becomes water, boiling point therefore, merely means the temperature at which the change occurs. Ammonia liquid, when glassifying, absorbs a great amount of heat from its surroundings, air, water or whatever they may be. So that if we put a tumbler full of the liquid into a basin of water, it would rub the water of enough heat to cause the formation of ice. The refrigerating machine generally employed on ships is one which constantly turns the ammonia liquid into gas and the gas back into liquid. The first process produces the cold used in the freezing rooms. The apparatus consists of three main parts. One, the compressor for squeezing ammonia gas. Two, the condenser for liquefying the gas. Three, the evaporator for glassifying the liquid. The compressor is a pump. The condenser, a tube or series of tubes outside which cold water is circulated. The evaporator, a spiral tube or tubes passing through a vessel full of brine. Between the condenser and evaporator is a valve which allows the liquid to pass from the one to the other in proper quantities. We can now watch the cycle of operations. The compressor sucks in a charge of very cold gas from the evaporator and squeezes it into a fraction of its original volume, thereby heating it. The heated gas now passes into the condenser coils and as it expands, encounters the chilling effects of the water circulating outside which robs it of heat and causes it to liquefy. It is next slowly admitted through the expansion valve into the evaporator. Here it gradually picks up the heat necessary for its gaseous form taking it from the brine outside the coils which has a very low freezing point. The brine is circulated by pumps through pipes lining the walls of the freezing room and robs the air there of its heat until a temperature somewhat below the freezing point of water is reached. The room is well protected by layers of charcoal or silicate cotton which are very bad conductors of heat. How the chamber strikes a novice can be gathered from the following description of a cuner liner's refrigerating room. It is a curious and interesting site. It may be a hot day on deck nearing New York and everyone is going about in sunheads and light clothes. We descend a couple of flights of stairs, turn a key, and here is winter sparkling in glassy frost upon the pale carcasses of fowls and game and ruddy joints of meat crystallizing the yellow apples and black grapes to the likeness of sweet meats in the grocer's shop gathering on the wall pipes in scintillating coats of snow nearly an inch deep. You can make a snowball down here if you like and carry it up on deck to astonish the languid loungers sheltering from the sun under the protection of the promenade deck roof such as the modern substitute for the old-time salt beef cask and bags of dried peas. The lodge is so near the kitchen that while below decks we may just peep into the kitchens where a white-capped chef presides over an army of assistants. Inside a huge oven are dozens of joints turning round and round by the agency of an invisible electric motor but what most tickles the imagination is an electrical egg boiling apparatus which ensures the correct amount of cooking to any egg. A row of metal dippers with perforated bottoms is suspended over a trough of boiling water. Each dipper is marked for a certain time one minute, two, three, four, and so on. The dippers filled with eggs are pushed down into the water. No need to worry lest they should be done to a bullet for at the expiry of a minute up springs the one minute dipper and after each succeeding minute the others follow in due rotation where 2,000 eggs or more are devoured daily. This ingenious automatic device plays no mean part. The search light. All liners and war vessels now carry apparatus which will enable them to detect danger at night time whether rocks or an enemy's fleet, icebergs, or a waterlogged derelict. On the bridge or on some other commanding part of the vessel structure is a circular glass-fronted case backed with a mirror of peculiar shape. Inside are two carbon points almost touching across which at the turn of a handle leaves a shower of sparks so continuous as to form a dazzling light. The rays from the electric arc as it is called either pass directly through the glass lens or are caught by the parabolic reflector and shot back through it in an almost parallel pencil of wonderful intensity which illumines the darkness like a ray of sunshine slanting through a crack in the shutter of the room. The search light draws its current from special dynamos which absorb many horsepower in the case of the powerful apparatus used on warships. At a distance of several miles a page of print may be easily read by the beams of these scrutinizers of the light. The finest search lights are to be found ashore at naval ports where in case of war a sharp lookout must be kept for hostile vessels. Portsmouth posts a light of over a million candle power but even this is quite eclipsed by a monster light built by the Schuchert company of Nuremberg, Germany which gives the effect of 816 million candles. An instrument of such power would be useless on warship owing to the great amount of current it devours but in a port connected with the lighting plant of a large town it would serve to illumine the country round for many miles. In addition to its value as an eye the search light can be utilized as a year. Ernst Rumer a German scientist has discovered a method of telephoning along a beam of light from a naval projector. The amount of current passing into the arc is regulated by the pulsations of a telephone battery and transmitter. If the beam be caught by a parabolic reflector in the focus of which is a selenium cell connected with a battery and a pair of sensitive telephone receivers the effect of these pulsations of light is heard. Selenium being a metal which varies its resistance to an electric circuit in proportion to the intensity of light shining upon it any fluctuations of the search lights beams cause electric fluctuations of equal rapidity in the telephone circuit and since these waves arise from the vibrations of speech the electric vibrations they cause in the selenium circuit are re-transformed at the receiver into the sounds of speech. This German apparatus makes it possible to send messages nine or ten miles over a powerful projector beam in the United States Navy and in other navies as well. Night signals are flashed by the electric light. The pattern of lamp used in the United States Navy is divided transversely into two compartments the upper having a white the lower a red lens. Four of these lamps are hung one above the other from a mast. A switchboard connected with the eight incandescent lamps in the series enables the operator to send any required signal one letter or figure being flashed at a time. During the Spanish-American war the United States fleet made great use of this simple system which on a clear night is very effective up to distances of four miles. Large arc lamps slung on yards over the deck give great help for calling and unloading vessels at night time. The touch of a switch lights up the deck with the brilliancy of a well-equipped railway station. The day of the lantern dimly burning has long passed away from the big liner cargo boat and warship. Wireless telegraphy instruments. Solitude is being rapidly banished from the Earth's surface. By solitude we mean entire separation from news of the world and the inability to get into touch with people far away. On the remote ranches of the United States in sequestered Norwegian fjords in the foes of the eternal hills where the only other living creature is the eagle men may still be as conversant with what is going on in China or Peru as if he were living in the busy streets of a capital town. The electric wire is the magic newsbringer. Wherever man can go, it can go too and also into many places besides. We must make one exception, the surface of the sea. Cables rest on oceans bed but they would be useless if floated on its surface to act as marine telegraph offices. Winds and waves would soon batter them to pieces even if they could be moored which in a thousand fathoms may be considered impracticable. So until a few years back the occupants of a ship were truly isolated from the time that they left port until they reached land again except for the rare occasions when a passing vessel might give them a fragment of news. This has all been changed so let's draw into the saloon of one of our large Atlantic liners and you will see telegram forms lying on the tables. In the 90s they would have been about as useful aboard ships as the Macintosh Coat in the Sahara. A glance, however, at pamphlets scattered around informs you that the ship carries a Marconi wireless installation and that a Marconi telegram handed in at the ship's telegraph office will be dispatched on the wings of either waves to the land far over the horizon. Inside the cabin streams of sparks scintillate with a cracking noise and your message shoots into space from a wire suspended on insulators from one of the masked heads. If circumstances favor you may receive a reply from the unseen before the steamer has got out of range of the coast stations. The immense installations at Poldu, Cornwall and in New Finland could be used to flash the words to a ship at any point of the transatlantic journey. Owing to lack of space and consequently power the steamer's transmitting apparatus has a limited capacity. The first shipping company to grasp the possibilities of the commercial working of the Marconi system was the Norddeutscher Lloyd whose mail steamer, Kaiser Wilhelm Diergroza, was fitted in March 1900. At the present time many of the large Atlantic steamship companies carry a wireless installation as a matter of course ranking it among necessary things. The Cunard, American Atlantic Transport, Allen, Company Transatlantic, Hamburg American and Norddeutscher Lloyd lines make full use of the system as the conveniences it gives far outweigh any expense. A short time since Maritime signalling was extremely limited in its range being affected by flags, semaphores, lights and sounds which in stormy weather became uncertain agents and in foggy useless. Also the operations of transmitting and receiving were so slow that many a message had to remain uncompleted. The following paragraph which appeared in the times of December 11th 1903 is significant of the very practical value of marine wireless telegraphy. The American steamer Crewland from Antwerp for New York which as reported yesterday disabled her steering gear when west of the fastnet and had to put back arrived yesterday morning at Queenstown. The saloon passengers speak in the highest terms of praise of the utility of the Marconi wireless telegraphy with which the liner is fitted and of the facility with which when the accident occurred the passengers were able to communicate with their friends in England, Scotland and the continent and even America and get replies before the Irish coast was cited. The accident occurred on Tuesday about noon when the liner was 130 miles west of the fastnet and communication was at once made with the Marconi station at Crookhaven. Captain Doxrod was enabled accordingly to send messages to the chief agents of the American line at Antwerp stating the nature of the damage to the steering gear of the steamer and that he would have to abandon the idea of prosecuting the Western voyage. Within an hour and a half a message was received by the captain from the agents instructing him what to do and at once the crew land was headed for Queenstown. Three fourths of the total number of the saloon passengers and a goodly number of the second cabin sent messages to their friends in various parts of the world and replies were received even from the continent before the fastnet was cited. Seven or eight passengers telegraphed to relatives for money and replies were received in four instances authorizing the purser to advance the amounts required and the money was paid over in each case to the passengers. The possibility of those communicating between vessel and land or vessel and vessel removes much of the anxiety attending a sea voyage. Businessmen for whom even a few days want of touch with the mercantile markets may be a serious matter can send long messages in code or otherwise instructing their agents what to do while they can receive information to shape their actions when they reach land. The uncommercial traveler also is pleased and grateful on receiving a message from home. The feeling of loneliness is eliminated. The ocean has lost its right to the term bestowed by Horace dissocial billus the separator. Steamship companies vie with one another in their efforts to keep their passengers well posted in the latest news. Bulletons or small newspapers are issued daily during the voyage which give in very condensed form accounts of events interesting to those on board. The amount of fresh news a steamer gathers during a passage is considerable and is greatly relished by the passengers who are invariably ravenous for signs of the busy life they left behind more especially when they have departed on the verge of some important event taking place and the bulletins are eagerly sought for when it is announced that an inward bound ship is in communication. The ship owners realize the importance and usefulness of being able to communicate with their commanders before the huge vessels enter narrow waters and issue instructions concerning their movements. The stations which are placed at carefully selected points at well adapted distances around the coast are connected with either the land telegraph or telephone line or are closed to a telegraph office. They're kept open night and day as the times of the ships passing are of course greatly dependent on the weather encountered during the voyage. For those unsure who are anxious to greet their friends on arrival with good or bad news as the case may be this arrangement enables them to be informed of the exact time of the ship's expected arrival and they are left free to their own devices instead of enduring long ways on droughty piers and docks which on a wet or windy day are almost enough to damp the warmest and most enthusiastic welcome. Cases have occurred where a telegram sent from the American side to an outlying English land station two days after a ship has left has been transmitted to an outgoing steamer which in turn has retransmitted it to the astonished passenger two days prior to his arrival off the English coast and it has now become quite a common thing for competing teams on vessels many miles apart and out of sight of each other to arrange chest matches with each other some of these interesting events taking two or more days to be played to a finish. For naval purposes wireless telegraphy has assumed an importance which can hardly be overestimated as the whole efficiency of a fine fleet may depend upon a single message flashed through space. All navies are fitting instruments the British Admiralty being well to the fore. Even in maneuvers and during the execution of tactical formations the apparatus is constantly at work the Admiral gives the word and a dozen paper tapes moving jerkily through Moore's machines pass the message round the fleet. The Japanese naval successes have doubtless being largely due to their up to date employment of this latest development of Western electrical science. No one knows how soon the time may come when the fate of a nation may depend on the proper working of a machine covering a few square feet of a cabin table for rapid as has been the growth of wireless telegraphy it is yet in its infancy safety devices. A ship is usually divided into compartments by cross bulkheads of steel in the event of a collision or damage by torpedoes or shell. The water rushing through the break can be prevented from swapping the ship by closing the bulkhead doors. Messers J Stone and company of depth for have patented a system of hydraulically operated bulkhead doors which is finding great favor among ship builders on account of its versatility. Each door is closed by an hydraulic cylinder placed above it. The valves of the cylinder are opened automatically by a float with the water rises in the compartment and every cylinder is also controllable independently from the bridge and other stations in the ship and by separate hand levers alongside the bulkhead. The doors can therefore be closed collectively or individually. Should it happen that when a door has been closed someone is imprisoned the prisoner can open the door by depressing a lever inside the compartment and make his escape. But the door is closed behind him by the action of the float. The transmission of power on the ship. There are four power agents available on board ship all derived directly or indirectly from the steam boilers. They are one steam to high pressure water three compressed air for electricity. On some ships we may find all four working side by side to drive the multifurious auxiliaries since each has its peculiar advantages and disadvantages. At the same time marine engineers prefer to reduce the number as far as possible since each class of transmission needs specially trained mechanics and introduces its special complications. Let us take the four agents in order and briefly consider their value. Steam is so largely used in all departments of engineering that its working is better understood by the bulk of average mechanics than hydraulic power, compressed air or electricity. But for marine work it has very serious drawbacks especially on a war vessel. Imagine a ship which contains a network of steam pipes running from end to end and from side to side. The pipes must on account of the many obstacles they encounter twist and turn about in a manner which might be avoided on land where room is more available. Every bend means friction and loss of power. Again the condensation of steam in long pipes is notorious. Even if they are well jacketed a great deal of heat will radiate from the ducts into the below deck atmosphere which is generally too close and hot to be pleasant without any such further warming. So that while power is lost discomfort increases with a decided lowering of human efficiency. We must not forget either the risk attending the presence of a steam pipe. Were it broken by accident or in a naval engagement a great loss of life might results or at least the abandonment of all neighboring machinery. For these reasons there is therefore a tendency to abolish the direct use of steam in the auxiliary machinery of a modern vessel. High pressure water is free from heating and danger troubles and consequently is used for much heavy work such as training guns, raising ashes and ammunition and steering. One of its great advantages is its inelasticity which prevents the overrunning of gear worked by it. Water being incompressible gives a positive drive thus if the pump delivers a pint at each stroke in the engine room a pint must pass into the motor assuming that all joints are tight and the work due from the passage of one pint is done. Air and steam and electricity too if not very delicately controlled are apt to work in fits and starts when operating against varying resistance and run away from the engineer. An objection to hydraulic power is that all leakage from the system must be replaced by fresh water manufactured on board which as we have seen is no easy task. Compressed air like steam may cause explosions but when it escapes in small quantities only it has a beneficial effect in cooling and freshening the air below decks. The exhaust from an air-driven boulder is welcome for the same reason that it aids ventilation. On the fighting ship it is of the utmost importance that the personnel should be in good physical condition and when the battle hatches have been battened down for an engagement any supply of fresh oxygen means an increased staying power for officers and crew. Poison air brings mental slackness and weakening of resolve so that if the motive power of heavy machinery can be made to do a second duty so much the better for all concerned. Compressed air also proves useful as a water excluder. If a vessel contain as it should a number of water-tight compartments any water rushing into one of these can be expelled by injecting air until the pressure inside is equal to that of the drought of water of the vessel outside. On land compressed air installations include reservoirs of large size in which air can be stored till needed and which take the place of the accumulator used with hydraulic power. On shipboard, want of space reduces such reservoirs to minimum dimensions so that the compressors must squirt their air almost directly into the cylinders which do the work. When the load or work is constantly varying this direct drive proves somewhat of a nuisance since the compressors if worked continuously at their maximum capacity must waste large quantities of air while if run spasmodically as occasion demands they require much more attention. It is therefore considered advisable by some marine engineers to make compressed air perform as many functions as possible when it is present on the vessel. The United States monitor terror is an instance of a warship which depends on this agency for working her guns and Tourette's handling ammunition and a somewhat unusual practice controlling the helm. The last operation is performed by two large cylinders placed face-to-face throughout the ship. They have a common piston rod in the middle of which is a slot for the tiller to pass through. Air is admitted to the cylinders by a valve which is controlled by wires passing over a train of wheels from different stations on the ship. An ingenious device automatically prevents the tiller from moving over too fast and also helps to lessen the shocks given to the rudder by a heavy sea. We now come to electricity the fourth and most modern form of transmission. Its chief recommendation is that the wires through which it flows lend themselves readily to a tortuous course without in any way throttling the passage of power. And as every ship must carry a generating plant for lighting purposes, the same staff will serve to tend a second plant for auxiliary machinery. Electric motors work with practically no vibration or light for their power and can be very easily controlled from a distance. They therefore enjoy increasing favor and are found in deck winches, anchor captains, ammunition hoists, ventilation blowers and cranes. They also control the movements of gun turrets having been found most suitable for this work. If the current were to get loose in the ship it would undoubtedly cause more damage than an escape of compressed air or water. Electricity, even when every known means of keeping it within bounds has been tried, is suspected of causing deterioration to the metalwork of ships. But these disadvantages are not serious enough to hamper the progress of electrical science as applied to marine engineering and the undoubted economy of the electric motor, its noiselessness, its manageableness and comparatively small size will no doubt in the future lead to its much more extensive use on board our floating palaces and floating forts. End of section 15. Section 16 of the Romance of Modern Mechanism. This is a LibriVox recording. A LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org. Recording by Betty B. The Romance of Modern Mechanism by Archibald Williams. The Nurse of the Navy. Just as a Navy requires floating distilleries, floating coal stores and floating docks, so does it find very important uses for a floating workshop which can accompany a fleet to sea and execute such repairs as might otherwise entail the return of a ship to port. The British Navy has a valuable ally of this kind in the torpedo depot ship Vulcan which contains so much machinery in addition to the auxiliaries already described that a short account of this vessel will be interesting. The Vulcan known as the Nurse of the Navy was launched in 1889. She measures 350 feet in length, 58 feet in beam, and has a displacement of 6,830 tons. Her bunkers, of which there are 21, hold 1,000 tons of coal, independently of an extra 300 tons which can be stowed in other neighboring compartments. When fully cold, she can cruise for 7,000 miles at a speed of 10 knots or travel at first class cruiser speed for shorter distances. The most striking objects on the Vulcan are two huge hydraulic cranes placed almost amid ships abreast of one another. They have a total height of 65 feet and overhang 35 feet so as to be able to lift boats when the torpedo nets are out and the sides of the vessel cannot be approached. The feet of the crane sink 30 feet through the ship to secure rigidity and the upper deck which bears most of the strain is strongly reinforced. Inside the pillar of each crane is the lifting machinery and hydraulic ram 17.5 inches in diameter and of 10-foot stroke. By means of four-fold pulleys, the lift is increased to 40 feet. When working under the full pressure of 1,000 pounds to the square inch, the cranes have a hoisting power of 20 tons. In addition to the main ram, there is a much smaller one, the function of which is to keep the slings or cables by which the boat is hoisted taught after a boat has been hooked until the actual moment of lifting comes. But for this arrangement, there would be a danger of the slings slackening as the boat rises and falls in a seaway. The small ram controls the larger and the ladder cannot come into action until its auxiliary has tightened up the slings so that no dangerous jerk can occur when the hoisting begins. The cranes are revolved by two sets of hydraulic rams which operate chains passing round drums at the feet of the cranes and turn them through three-quarters of a circle. On the Vulcan's deck lie six torpedo boats and three dispatch boats. The former are 60 feet long and can attain a speed of 16 knots an hour. When an enemy is sighted, these will be sent off to worry the hostile vessels with their deadly torpedoes and on their return would be quickly picked up and restored to their berths ready for further use. The cranes also serve to lift on board heavy pieces of machinery from other vessels for repair. Down below decks is the workshop wherein jobs are done on the high seas. It has quite a respectable equipment, five lathes ranging from 15 feet to three and a half feet in length. Drilling, planing, slotting, shaping, punching machines, a carpenter's bench, fitter's benches and a furnace for melting steel. There's also a blacksmith's shop with a hydraulic forging press and a forge blown by machinery not to mention a large array of tools of all kinds. Special engines are installed to operate the repairs department. The Vulcan also carries search lights of 25,000 candle power, bilge pumps, which will deliver over 5,000 tons of water per hour. Two sets of engines for supplying the hydraulic machinery, air compressing engines to feed the whitehead torpedoes, a distilling plant and last but by no means least main engines of 12,000 HP drawing steam from four huge cylindrical boilers 17 feet long and 14 feet in diameter. Altogether the Vulcan is a very complete floating workshop sufficiently speedy to keep up with the fleet and even to do scouting work. Her guns and her torpedo craft would render her a very troublesome customer in a fight. Though being practically unarmored, she would keep as clear of the conflict as possible acting on the offensive through the proxy of her hornets. She constitutes the first of a type of vessel which has been suggested by experts. These one of high speed and unarmored but capable of carrying a swarm of torpedo boats which could be launched in pursuit of the foe. Even if 50% of the craft were destroyed the price would be small if the single torpedo were successfully fired at a battleship. The naval motor boat to which reference has already been made would just fill the bill for such a cruiser and in the event of a score of them being dropped into the water at a critical moment they might easily turn the scale in favor of their side. End of section 16 Section 17 of the Romance of Modern Mechanism This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer please visit LibriVox.org Recording by JennyTB from creationpeak.com The Romance of Modern Mechanism by Archibald Williams The Mechanism of Diving Diving being a profession which can be carried on in its simplest form with the simplest possible apparatus merely a rope and a stone its history reaches back into the dim an inexplorable past. We may well believe that the first man who explored the depths of the sea for treasure lived as long ago as the first seeker for minerals in the bosom of the earth. Even when we come to the various appliances which have been gradually developed in the course of centuries our records are very imperfect. Alexander the Great is said to have descended in a machine which kept him dry while he sought for fresh worlds to conquer below the waves. Aristotle mentions a device enabling men to remain some time underwater. This is all the information and a very meager total too that we get from classical times. Stepping across 1,500 years we reach the 13th century about the middle of which Roger Bacon is said to have invented the Diving Bell but like some other discoveries attributed to that middle-age physicist the authenticity of this rests on very slender foundations. In a book published early in the 16th century there appears an illustration of a diver wearing a cap or helmet to which is attached a leather tube floated on the surface of the water by an inflated bag. This is evidently the diving dress in its crudest form and when we read how in 1538 two Greeks made a submarine trip under a huge inverted chamber which kept them dry in the presence of the great Emperor Charles V and some 12,000 spectators we recognize the Diving Bell now so well known. The latter device did not reach a really practical form till 1717 when Dr. Halley, a member of the Royal Society built a bell of wood lined with lead. The divers were supplied with air by having casks full lowered to them as required. To quote his own words to supply air to the spell under water I caused a couple of barrels of about 30 gallons each to be cased with lead so as to sink empty each of them having a bunghole in its lowest parts to let in the water as the air in them condensed on their descent and to let it out again when they were drawn up full from below. And to a hole in the uppermost parts of these barrels I fixed a leathern hose long enough to fall below the bunghole being kept down by a weight appended so that the air in the upper parts of the barrels could not escape unless the lower ends of these hose were first lifted up. The air barrels being thus prepared I fitted them with tackle proper to make them rise and fall alternately after the manner of two buckets in a well. And in their descent they were directed by lines fastened to the under edge of the bell which passed through rings on both sides of the leathern hose in each barrel so that, sliding down by these lines they came readily to the hand of a man who stood on purpose to receive them and to take up the ends of the hose into the bell. Through these hose as soon as their ends came above the surface of the water in the barrels all the air that was included in the upper parts of them was blown with great force into the bell whilst the water entered at the bungholes below and filled them. And as soon as the air of one barrel had been thus received upon a signal given that was drawn up and at the same time the other descended and by an alternate succession provided air so quick and in such plenty that I myself have been one of five who have been together at the bottom in nine to ten fathoms water for above an hour and a half at a time without any sort of ill consequence and I might have continued there so long as I pleased for anything that appeared to the contrary. After referring to the fact that when the sea was clear and the sun shining he could see to read or write in the submerged bell thanks to a glass window in it the doctor goes on to say this I take to be an invention applicable to various uses such as fishing for pearls diving for coral or sponges and the like in far greater depths than has hitherto been thought possible also for the fitting and placing of the foundations of moles bridges etc. in rocky bottoms and for cleaning and scrubbing ships bottoms when foul in calm weather at sea I shall only intimate that by an additional contrivance I have found it not impractical for a diver to go out of an engine to a good distance from it the air being conveyed to him with a continued stream by small flexible pipes which pipes may serve as a clue to direct him back again when he would return to the bell we have italicized certain words to draw attention to the fact that dr. Halle had invented not only the diving bell but also the diving dress though he foresaw practically all the uses to which diving mechanisms could be put the absence of a means for forcing air under pressure into the bell or dress greatly limited the utility of his contrivances since the deeper they sank below the water the further with the latter rise inside them it was left for John Smeaton of Eddy Stone Lighthouse fame to introduce the air pump as an auxiliary which by making the pressure of the air inside the bell equal to that of the water outside kept the bell quite free of water Smeaton replaced Halle's tub by a square solid cast iron box 50 hundred weight in weight large enough to accommodate two men at a time the modern bell is merely an enlarged addition of this type furnished with telephones electric lamps and in some cases with the special airlock into which the men may pass when the bell is raised the pressure in the airlock is very gradually decreased after the bell has reached the surface if work has been conducted at great depth so that the evil effects sometimes attending a sudden change of pressure on the body may be avoided Diving bells are very useful for laying submarine masonry usually consisting of huge stone blocks set in hydraulic cement helmet divers explore and prepare the surface on which the blocks are to be placed then the bell slung either from a crane on the masonry already built above water level or from a specially fitted barge comes into action the block is lowered by its own crane on to the bottom the bell descends upon it and the crew sees it with tackle suspended inside the bell instructions are sent up as to the direction in which the bell should be moved with its burden and as soon as the exact spot has been reached the signal for lowering is given and the stone settles on to the cement laid ready for it the modern diver is not sent out from a bell but has his separate and independent apparatus the first practical diving helmet was that of Kleingert a German this enclose the diver as far as the waist and constituted a small diving bell since the bottom was open for the escape of vitiated air 20 years later or just a century after the invention of Halley's Bell Augustus Sieb the founder of the present great London firm of Sieb Gorman and Company produced a more convenient open dress consisting of a copper helmet and shoulder plate in one piece attached to a waterproof jacket reaching to the hips the disadvantage of the open dress was that the diver had to maintain an almost upright position or the water would have invaded his helmet Mr. Sieb therefore added a necessary improvement and extended the dress to the feet giving his diver a clothes protection from the water we may pass over the gradual development of the clothes dress and glance at the most up-to-date equipment in which the toilets of the deep explore the bed of old ocean the dress legging body and sleeves is all in one piece with the large enough opening at the shoulders for the body to pass through the helmet with front and side windows is attached by a bayonet joint to the shoulder plate itself made fast to the upper edge of the dress by screws which press a metal ring against the lower edge of the plate so as to pinch the edge of the dress at the back are an inlet and an outlet valve between the front and a side window is the transmitter of a loud sounding telephone and in the crown the receiver and the button of an electric bell the telephone wires and also the wires for a powerful electric light working on a ball and socket joint in front of the dress are embedded into the lifeline the air tube of canvas and rubber has a stiffening of wire to prevent its being throttled on coming into contact with any object a pair of weighted boots each scaling 17 pounds 240 pound lead weights slung over the shoulder and a knife worn at the waist belt complete the output of the diver which not including the several layers of under-clothing necessary to exclude the cold found at great depths totals nearly 140 pounds of this the copper helmet accounts for 36 pounds on the surface are the air pumps which may be of several types single cylinder double acting double cylinder double acting or three or four cylinder single acting according to the nature of the work all patterns are so constructed that the valves may be easily removed and examined the pressure on a diver increases in the ratio of about four and a quarter pounds for every 10 feet he descends below the surface a novice experiences severe pains in the ears and eyes at a few fathoms depth which however pass off when the pressures both inside and outside of the various organs have become equalized on rising to the surface again the pains recur since the external pressure on the body falls more quickly than the internal the rule for all divers therefore is slow down slow up men of good constitution and resourcefulness are needed for the profession of diving only a few can work at extreme depth though an old hand is able to remain for several hours at a time in 60 feet of water the record depth reached by a diver is claimed by James Hooper who when removing the cargo of the Cape Horn wrecked off the coast of South America made seven descents to 201 feet one of which lasted 42 minutes in spite of the dangers and inconveniences attached to his calling the diver finds it in compensations and even fascinations which outweigh its disadvantages the pay is good one pound to two pounds a day and in deep sea salvage he often gets a substantial percentage of all the treasure recovered the percentage rising as the depth increases thus the diver Alexander Lambert who performs some plucky feats during the driving of the Sovereign Tunnel received 4,000 pounds for the recovery of 70,000 pounds worth of gold from the Alfonso 12 sunk off Grand Canary divers Rydjord and Pink recovered 50,000 pounds from the Himila Mitchell which lay in 160 feet of water off Shanghai after nearly being captured by Chinese pirates and we could add many other instances in which treasure has been rescued from the maw of the sea the most useful sphere for a diver is undoubtedly connected with the harbor work and the cleaning of ships bottoms for the latter purpose every large warship in the British Navy carries at least one diver after ships have been long in the water barnacles and marine growths accumulate on the below water plates in such quantities as to seriously diminish the ship's speed which means a great waste of fuel and would entail a loss of efficiency in case of war breaking out armed with the proper tools a gang of divers will soon clean the fowl bottom at a much smaller cost of time and money than would be incurred by dry docking the vessel the Navy has at Portsmouth, Sheerness and Devonport schools where diving is taught to picked men the depth in which they work being gradually increased to 120 feet Messers Sieb and Gorman employ hundreds of divers in all parts of the world on all kinds of submarine work and they are able to boast that never has a defect in their apparatus been responsible for a single death this is due both to the very careful tests to which every article is subjected before it leaves their works and also to the thorough training given to their employees in the sponge and pearl fishing industries the diving dress is gradually ousting the unaided powers of the naked diver one man equipped with a standard dress can do the work of 20 natural divers and do it more efficiently as he can pick and choose his material this chapter may conclude with a reference to the apparatus now used in exploring or rescue work in mines where deadly fumes have overcome the miners it consists of an airtight mask connected by tubes to a chamber full of oxygen and to a bag containing materials which absorb the carbonic acid of exhaled air the wearer uses the same air over and over again and is able to remain independent of the outer atmosphere for more than an hour the apparatus is also useful for firemen when they have to pass through thick smoke end of section 17 recording by Jennie T.B. from creationpeak.com section 18 of The Romance of Modern Mechanism this is a LibriVox recording all LibriVox recordings are in the public domain for more information or to volunteer please visit LibriVox.org The Romance of Modern Mechanism by Archbold Williams Chapter 15 Apparatus for Raising Sunken Ships and Treasure it is somewhat curious that while the science is connected with the building of ships have progressed with giant strides little attention has been paid to the art of raising vessels which have found watery graves in comparatively shallow depths the total shipping losses of a single year make terrible reading since they represent the extinction of many brave sailors and the disappearance of huge masses of the world's wealth a life lost is lost forever but cargoes can be recovered if not sunk in water deeper than 180 feet yet with all our modern machinery the percentage of vessels raised from even shallow depths is small there are practically only two methods of raising a foundered ship first to caulk up all leaks and pump her dry and secondly to pass cables under her and lift her bodily by the aid of pontoons or camels the second method is that more generally used especially in the estuaries of big rivers where there is a considerable tide the pontoons having a united displacement greater than that of the vessel to be raised are brought over her at low tide divers pass under her bottom huge steel cables which are attached to the camels as the tide flows the pontoons sink until they have displaced a weight of water equal to that of the vessel and then they begin to raise her and can be towed into a shallower water to feed the process if necessary next tide as soon as the deck is above water the vessel may be pumped empty when all leaks have been stopped in water where there is no tide the natural lift must be replaced by artificial power under such circumstances the salvage firms use lighters provided with powerful winches each able to lift up to 800 tons or huge steel cables nearly a foot in diameter the winches can be moved across a lighter the cables falling perpendicularly through transverse wells almost dividing the lighter into separate lengths so as to get a direct pull if the wreck has only half the displacement of the lighters the cables can be passed over rollers on the inner edges of the pontoons the weight of the raising vessel being counteracted by water let into compartments in the outer side of the pontoons there are ten great salvage companies in the British Isles and Europe the best equipped of these is the Neptune Company of Stockholm which has raised 1,500 vessels worth over 5 million sterling even in their damaged condition among them the ill-fated submarine A1 yet this total represents but a small part of the wealth that has gone to the bottom within a short distance of our coasts turning from the salvage of wrecks to the salvage of precious metal and bulky objects that are known to screw the sea floor in many places we must notice the hydroscope the invention of Cavalier Pinot an Italian in 1702 there sank in Vigo Bay on the northwest coast of Spain 25 galleons laden with treasure from America as a result of an attack by English and Dutch men of war gold representing 28 million pounds was in those vessels down it went to the bottom and there it is still so richer prize has naturally not failed to attract daring spirits among whom was Giuseppe Pino this inventor has produced many devices the most notable among them the hydroscope which may best be described as a huge telescope for peering into the depths of the sea a large circular tank floats on the top of the water from the center of its bottom hangs a series of tubes fitting one into the other so that the whole series can be shortened or lengthened at will through the tubes a man can descend to the chamber at their lower extremity in the sides of which are 12 lenses specially made by Saint Gobain of Paris which act as submarine telescopes Pino's hydroscope has been at work for some time in Vigo Bay its operations closely watched by a Spanish war vessel which will exact 20% of all treasure recovered while the hydroscope acts as an eye the lifting of an object is accomplished by attaching to it large canvas bags furnished with airtight internal rubber bladders these have air pumped into them till its pressure overcomes that of the water outside and the bag then rises like a cork carrying its load with it an elevator nine sacks fixed to one frame will raise 25 to 30 tons so far Valier Pino has salvaged old Spanish guns cannonballs and pieces of valuable old wood and presently he may alight on the species which is the main object of his search another Spanish wreck in Florida which was a unit of the Spanish Armada and sank in Tobremory Bay the Isle of Mole has many times been attacked by divers the last attempt made to recover the treasure which that ill-fated vessel was reputed to bear is that of the steam lighter sea light which employed a very powerful sand pump to suck up any object to counter on the sea bottom many interesting relics have been raised by the pumps and attendant divers coins, bones, jewels timbers, cannon muskets, pistols, swords and a compass which is so constructed that pressure on the top causes the legs to spread one of the cannon 54 inches long has a separate powder chamber the shot and wad still in the gun and traces of powder in the chamber it is curious that what we usually consider so modern an invention as the bridge loading cannon should be found side by side with stone balls the heavier objects were of course raised by divers in this quest also the treasure deposit has not yet been tapped end of section 18 section 19 of the romance of modern mechanism this is a LibriVox recording all LibriVox recordings are in the public domain for more information or to volunteer please visit LibriVox.org the romance of modern mechanism by Archibald Williams chapter 16 the handling of grain the elevator the section pneumatic grain lifter the pneumatic blast grain lifter the combined system on or near the quays of our large seaports, London Liverpool, Manchester Bristol, Hull, Leith, Dublin may be seen huge buildings of severe and ugly outline utterly devoid of any attempts at decoration yet we should view them with respect for they are to the inhabitants of the British Isles what the inland granaries of Egypt were to the dwellers of the Nile in the time of Joseph to strip off the roofs and walls of these structures we should see vast bins full of wheat or spacious floors deeply strewn with the material for countless loaves the grain warehouses of Britain the Americans would term them elevators have a total capacity of 10 million quarters multiply those figures by 8 and you have the number of bushels each of which will yield the flour for about 42 pound loaves and these granaries is stored the grain which comes from abroad with the opening up of new lands in North and South America and the exploitation of the great wheat growing steps of Russia English agriculture has declined and we are content to import 5-6 of our breadstuffs and an even larger proportion of grain foods for domestic animals and arrives from the United States India Russia, Argentina, Canada and Australia and vessels often built specially for grain transport and as it cannot be immediately distributed must be stored in bulk and properly designed buildings these contain either many stories of which the grain is spread to get rid of superfluous moisture which might cause dangerous heating or huge bins or silos in which it can be kept from contact with the air experiments have proved that wheat is more successfully preserved than if left in the open provided that it is dry the ancient Egyptians used brick granaries filled from the top and tapped at the bottom in which to judge by the account of a grievous famine given in the book of Genesis the wheat was preserved for at least 7 years during last century the silo fell into disrepute but now we have gone back to the Egyptian plan of closed bins which are constructed of wood brick, ferrule concrete or iron and are of square hexagonal or round section they are set close together many under one roof to economize space as many as 2,985,000 bushels being provided for in the largest English door house such vast quantities of grain require well devised machinery for their transport from ship to bin or floor weighing clearing and for their transference to barges or railway trucks the Alexander grain warehouse of Liverpool may be taken as a typical example of a well equipped silo granary measures 240 x 172 feet and contains 250 hexagonal bins of brick work each 80 feet deep and 12 feet in diameter the grain is lifted from barges by 4 elevators placed at intervals along the edge of the quay the elevators of wooden case 40 or 50 feet high in which an endless band furnished with buckets travels over two rollers placed at the top and bottom these are let down into the hold and scoop up the grain at the rate of from 75 to 150 tons per hour according to their size as soon as a bucket reaches the top roller it empties its charge into a spout which delivers the grain into a bin which it is lifted again 32 feet by a second elevator to a bin in which it flows by gravity to a weighing hopper beneath and as soon as 2 tons is collected the contents are emptied automatically into a distributing hopper after all this the grain still has a long journey before it for it is now shot out onto an endless flat conveyor belt moving at a rate of 9 to 10 feet per second it is carried horizontally by this for some distance along the quay and falls onto a second belt moving at right angles to the first which whisks it off to the receiving elevators of the storehouse once more it is lifted this time 132 feet to the top floor of the building and dropped onto a third belt which runs over a movable throwing off carriage this can be placed at any point of the belt's travel to transfer the grain to any of the spouts leading to the 250 bins here at rest for a time when needed for the market it flows out at the bottom of a bin onto belts leading to delivery elevators from which it may either be passed back to a storage bin after being well aired or shot into wagons or vessels from first to last a single grain may have to travel 3 miles between the ship and the truck without being touched once by a human hand the vertical transport of grain is generally affected by an endless belt to which buckets are attached at short intervals the grain fed to the buckets either by hand or by mechanical means is scooped up world aloft and when it is past the topmost point of its travel and just as the bucket is commencing the descent it flies by centrifugal force into a hopper which guides it to the traveling belt as already described of late years however much attention has been paid to by which a cargo is transferred from ship to storehouse or from ship to ship through flexible tubes the mode of power being either the pressure of atmospheric air rushing in to fill a vacuum or high pressure air which blows the grain through the tube in much the same way as a steam injector forces water into a boiler sometimes both systems are used in combination we will first consider these methods separately the suction pneumatic grain lifter is the invention of Mr. Fred E. Duckham engineer of the mill wall docks London the ships in which grain is brought to England often contain a mixed cargo as well and that the unloading of this may proceed simultaneously with the moving of the wheat it is necessary to keep the hatches clear as long as the grain is directly under a hatch way a bucket elevator can reach it but all that is not so conveniently situated must be brought within range of the buckets this means a large bill for labour even if machinery is employed to help the trimming Mr. Duckham therefore designed an elevator which could easily reach any corner of a ship's interior the principal parts are a large cylindrical airtight tank an engine to exhaust air from the same and long hoses armoured inside with the steel lining connected at one end to the tank and furnished at the other with a nozzle these hoses extend from the receiving tank to the grain which when the air has been exhausted to five or six pounds to the square inch flies up the tubes into the tank at the bottom of the tank are ingenious air locks to allow the grain to pass into a bin below without emitting air to spoil the vacuum the locks are automatic and as soon as a certain quantity of grain has collected tip sideways closing the port which it flowed and allowing it to drop through a hinged door two locks are attached together to one discharging while the other is filling an elevator of this kind will shift 150 tons or more an hour Mr. Duckham claims for his invention that it has no limit in capacity it is practically independent of everything but its own steam power and the labour of one man suffices to keep its flexible suckers buried in grain no corners inaccessible to the nozzle the pipes occupy only a very small part of the hatch way they can be set to work immediately a vessel comes alongside as many as a quarter of a million bushels are handled daily by one of these machines the pneumatic elevator is often installed on a floating base so that it may be moved about in a dock the pneumatic blast grain lifter differs from the system just described in that the grain is driven through the pipes or hoses by air compressed to several pounds above atmospheric pressure a small tube attached to the main hose conveys compressed air to the nozzle to which grain enters the tube the nozzle consists of a short length of metal piping which is buried in the grain one half of it is encased by a jacket into which the compressed air rushes as the air escapes at high speed from the inner end of the piping into the main hose it causes a vacuum in the piping and draws in grain which is shot up the hose by the pressure behind it as already remarked the action of this pneumatic elevator is similar to that of a steam injector the combined system under some conditions it is found convenient to employ both suction and blast in combination suction to draw the grain from a vessel's hold into elevators from which it is transferred to the warehouse by blast special boats are built for this work e.g. the Gary Owen which has on board suction plant for transferring grain from a ship to barges and also blowing apparatus for elevating it into storehouses or into another ship the Gary Owen has the hole in engines of an ordinary screw steamer so that it can ply up and down the Shannon load of vessel to reduce it's drought sufficiently to allow it to reach limerick docks floating elevators of this kind are able to handle upwards of 150 tons of grain per hour end of section 19