 Beneath this barren mass of rock and snow, 14,000 feet up in the Peruvian Andes lies the lost city of Ranrairka. There are many lost cities in Peru, but Ranrairka is unique. For until 613, on the evening of January 10, 1962, it was a thriving community of three or four thousand human souls. At that instant, Towering Mount Wascaran hurled into the valley below three million tons of ice, snow, rock, and mud, engulfing in just seven minutes the town and all it contained. Today, Ranrairka is the site of a modern scientific detective story, part of the continent-spanning story of today's big picture. This is the canal zone headquarters of one of the most interesting organizations of the United States Army, the Inter-American Geodetic Survey. It is familiar throughout Latin America as the Servicio Geodesico Interamericano. This is the IAGS director, Colonel John E. Unverforth of the Corps of Engineers. During World War II, U.S. forces learned the hard way what it is to fight in lands not covered by accurate maps. In fact, even in the United States, less than half of the area is covered by accurate large-scale maps. In 1946, the Inter-American Geodetic Survey was activated to assist Latin America in solving this problem. The bulk of the mapping work being performed in each of the 16 Latin American countries is being performed by indigenous personnel of each country. The IAGS is an engineer unit assigned to the United States Army Southern Command. Our most important objective is to establish in each country a self-sufficient mapping organization. In terms of dollars, the Latin American countries spend more on the program than we do, whereas we have 640 employees, the Latin American countries have over 4,000 people participating. Most of these Latin American technicians are trained right here in our IAGS cartographic school in the Canalzo. The school is the technical training center of the 8,000 square miles of territory over which our program currently operates. I'm Ken Reinhart, an instructor here at the Cartographic School, and this is one of the classrooms where students from all over Latin America are assembled every few months to receive intensive instruction in the extremely complicated techniques of modern map-making. In this single group, for example, are technicians from 11 different countries. The classes in the school are all of course conducted in Spanish. The linguistic ability is only one of the many special skills required of our personnel. Now you take the average man who drives into a filling station and picks up a road map. He has little, if any, idea of what goes into the making of that map. The aerial photographs the students are working with are the first, and in some ways the easiest, step in modern topographical map-making. They are only the beginning of the process, yet they require something in the neighborhood of a million dollars worth of specialized equipment and training incorporated into this Air Force C-130 on an airstrip in Peru. I am Captain Miller. I am a photo aircraft commander on a Lockheed RC-130. This C-130 has been modified by the addition of highly accurate photographic equipment to provide the type of photographs with which modern-day map-making begins. The special high-speed cameras within this aircraft enable us to shoot one picture every 45 seconds while flying at speeds up to 300 miles an hour. They can distinguish a ditch or a fence line from altitude of more than 30,000 feet. The strips from our cameras become the basis of the map-maker's art, saving not only millions of dollars, but thousands of man-hours of wading rivers, climbing mountains, and hacking through jungles. Here in Peru, due to a strange coincidence, our plane actually made it possible for the cartographers to map a city which no longer existed. The officer-in-charge of the IHS Peru project. This is Colonel Luis Montezuma Delfin, the director of the Instituto Geográfico Militar of Peru. Films of Ron Rayerca, mentioned by Captain Miller, were taken as a regular part of our mapping program just one day prior to the avalanche. Immediately after this catastrophe, the U.S. Air Force returned for another set of photos, giving us the only scientific before and after photography of a glacial landslide ever taken. We can't say that Ron Rayerca was wiped off the map because Ron Rayerca was never on a map in the first place. Although the village was completely obliterated, we were able to determine what was buried beneath the 30 to 60 foot of rock and mud. When the aerial photographs were brought to the Institute, the technicians worked through many laborious processes to the final stages of training a finished map of Ron Rayerca. This is possibly the first time that map makers have ever been required to draw a map down to the last building in Fencepost of a city that no longer exists. We can now estimate the damage. In addition, scientists all over the world can study these documents in an attempt to learn more about the critical point at which an avalanche occurs and the time that it might occur. And modern techniques certainly have advanced the art of map making. For example, Senor Hernandez of Venezuela is using a device called a kelch plotter to convert a set of aerial photographs into a contour map. The instrument projects images from overlapping pictures onto a drawing table, colored lights and matching lenses in the glasses he wears give him a three-dimensional image which enables him to begin tracing contours. To complete his job, however, the operator must know the exact altitude and location of four points identifiable in his photographs. This is where the sweat and sometimes the adventure comes in. In the rugged terrain which characterizes most of Latin America, the helicopter has become an almost indispensable tool of the modern surveyor, often carrying him in hours to sites which once could be reached only after days or weeks of backbreaking effort. Places remain, however, whose remoteness defies even the modern aircraft. To reach their destination, this Nicaraguan crew will travel by boat and by foot through the jungle heartland of Central America. The survey party carry in their duffel bags the most modern of scientific mapping equipment, but their living conditions along the route are more rugged than anything encountered by surveyor George Washington on the frontiers of North America two centuries ago. Intense heat and tangled undergrowth so thick in places that paths must be carved out with machetes a few feet at a time are handicaps which the surveyor in this part of the world soon learns to take for granted. The traveler in this particular jungle must move with exceptional care for the tropical forests of Nicaragua contain possibly the most extensive collection of poisonous snakes in the western hemisphere. Here is one reason why foot power in some parts of the world still holds its own in competition with air power. The refueling problem is a great deal easier. Blood, sweat, and tears which go into the making of a map are among its most important ingredients although usually unknown to everyone except the unsung heroes who supply them. This is a leveling party. Their job is to determine the elevations of various key points along the survey route. By taking successive readings on the level rods held by his companions the observer can determine the relative elevations of all important terrain points in the area. Officer in charge of the Nicaraguan project is Major Jonathan Miner. Now every mapping problem doesn't involve a trip like the one that we just finished. There are however plenty of them and enough of them to make the job very interesting. And as Ken Reinhart said that much of this mathematical data that we have can be run through or crank through a cartographer's machine in just no time at all. However even in the advanced age that we're in these days the fact remains that sooner or later a man is going to have to shoulder a tripod and go out into the bush. And as a lot of my people say IAGS stands for I'm always going somewhere. These are the Bolivian Andes and this IAGS crew is 2,300 miles south of Major Miner's group in Nicaragua and 16,000 feet higher up. I'm Major Art Ellion. I'm in charge of the IAGS Bolivia project. Our climate is different here whereas Major Miner's problems are with the heat and snakes. Ours is the cold and at this altitude in the Andes the difficulty of getting enough oxygen to keep going. Our basic job however is the same. In Bolivia we have these extensive mountains that we're surveying at this moment. The large population of the country lives on the Altiplano. A plateau at about 13,000 feet and these beautiful mountains are a barrier. Our maps will permit the construction of the roads across these mountains and the movement of these people as colonizers down into the more fertile parts of this country. The IAGS is also helping to create a natural resource in the form of scientific technicians as our work progresses in each country. This Peruvian officer in his base camp high in the Altiplano of Peru uses the remaining hours of daylight to correlate results of the day's survey with aerial photographs of the area. The job of cartography is one for resourceful, energetic men. In addition to their technical skills they must bring to their work all the craft of the experienced outdoorsmen. In this part of the world there is often no quartermaster, no mess hall. A survey party often lives off the land on the same food and under the same conditions as the local population or compensations. A life filled with days and weeks in the midst of great scenic beauty and of many hours spent with men of different backgrounds and unfamiliar customs with whom affords those bonds of friendship known only to men who have shared a common, challenging experience. Geodesy measuring stations like this one in the Peruvian Andes have been set up and accurate measurements are being taken throughout the hemisphere. The force of gravity varies slightly from place to place on the Earth's surface and accurate measurements are crucial in the sciences of geodesy and geophysics. It is only through the correlation of scientific investigations such as these throughout the world that a true picture of the size and shape of the Earth can be developed. A AGS also maintains tide gauge stations in 70 coastal locations. These are extremely important in the business of map making for the elevation of any point on any map is ultimately determined by the average sea level along the sea coast. To determine this level accurately requires a continuous recording of tidal changes for almost 19 years. Tide gauge stations also maintain constant checks on the density and temperature of the local seawater. Such information while of no value to the map maker is immensely useful to marine biologists and other scientists. Another example of an important byproduct of the IAGS mapping program. Peruvian Andes so high as to seem part of the sky itself stand the ruins of the ancient Incan city of Machu Picchu. For centuries Indian legend maintained that the last of the Incan leaders had escaped captured by the Spanish conquistadores and retreated to a secret city above the clouds. In modern times has the legend proved to have a basis in fact with the discovery of Machu Picchu. A favorite tourist attraction this legend come to life is just one more target for mapping to a geodetic surveyor. Early travelers seeking the kingdom of the Incas looked not for mountains but desert. Sail the coast southward. When there are no longer any trees you are in Peru. Such were the sailing directions given 16th century navigators. While hardly sufficient for the modern geographer the directions were surprisingly accurate. For beginning in Peru the seat ghost of South America becomes a desert which is almost without visible plant life for a stretch of over 2,000 miles. Map making in such almost featureless terrain requires utmost accuracy since there are so few physical details against which to double check the observers findings. The difficulties are somewhat compensated for by the extraordinary visibility which the desert affords. At least here there is no mile of jungle to be cut down before the observer can get a clear view of his sighting point. The basis of map making is today much the same as it was in ancient Greece or Egypt. The problem is to determine distances and directions between recognizable points. Technological advances of today however have added speed and efficiency to the application of ancient mathematical rules. By means of portable radios the surveyors can coordinate their efforts over great distances. At each location the mirrors of a heliotrope provide a sighting point for the theodolites of the other party. Direction or azimuth is controlled by a theodolite which is used to determine angular measurement. This party is also equipped with a teleurometer. A device which applies electronics to distance measurement and gives direct information which otherwise would require much more laborious geometric calculations. A teleurometer uses the radar principle sending out a radar impulse which is received at a distance station and returned. Measurement of the time required for the round trip and knowledge of the speed of the radar impulse permit computation of the distance. It looks simple but in practice according to one IAGS engineer surveying is half mathematics and half endurance. The training of technicians in the field of map making is as important a part of the IAGS mission as the maps themselves. With the bulk of the work being done by citizens of the collaborating countries the result will be a legacy of scientifically trained manpower which may have a profound effect on the future economic development of the hemisphere. And while laying the groundwork for future development of their own country's resources such technicians are contributing to the expanding body of the world's scientific knowledge. The map maker's art takes him wherever the science of cartography dictates. It is not always desert or the jungle. It may take him for instance through the heart of Lima one of the great cities of the western hemisphere. Here the surveyor sometimes feels more like a movie star than a cartographer and there are those who have been known to prefer the privacy of mountain jungle or desert. So far we have seen just a few of the major efforts which go into that impressive looking map you find in your atlas. But locations on a map have names somebody has to put them there and that can be quite an adventure in itself. This job falls to a man known as a field classifier. The field classifier is part explorer part cartographer part detective and part linguist. He must not only determine the local name for the islands villages or waterways which appear on his map but frequently decide such matters as the appropriate spelling for a designation furnished by a native who has no written language. The field classifier is not the final judge of this nomenclature which may require months of study and debate by learned scholars in the country involved. But it is his responsibility to give them alternatives from which to choose and he usually finds it an interesting job. Who report on the inter-american geodetic survey could be complete without a very special mention of the 937th engineer company, a group of army aviation pilots who routinely perform one of the most adventurous jobs in flying today. The tools of their trade are 42 aircraft including 16 helicopters. The pilots many of whom are members of corps of engineers not only fly technicians in and out of some of the most inaccessible locations in the world but frequently assist in the technical jobs of map making. Pilots of the 937 flying at low altitudes over unexplored terrain are among the last of the real bush pilots. Ironically for men who are part of the largest mapping enterprise ever undertaken, their job is made especially hazardous by the fact that where they fly there are no reliable maps, otherwise they wouldn't be there. It would be hard to exaggerate the role of a modern helicopter in the work of men who must go to remote places and survive there long enough to do a job. And the job required for an accurate detailed topographic map is far more exacting than anything which goes into the simple road map with which most people are familiar. How much of the Earth's surface particularly in the western hemisphere remains as much terra incognito as it was when Columbus set sail for the new world. The time is now in sight when doubt and uncertainty can be replaced by scientific knowledge. This achievement will owe a large debt not only to cartographers but to the versatility of army aircraft and to the army aviators who pilot them. DGS aircraft are often the only light aircraft available in the interior. They are frequently called upon to perform mercy missions. Their record of service in time of national and personal disaster is second to none. The important thing to remember about our program is that we are not mapping Latin America. We are merely assisting the 16 Latin American countries in mapping their own national territory. We lend them equipment, we train their people, and we give them technical advice. But it's their program. The demand for large scale maps is increasing every day. They are needed for the construction of their roads, building their power projects, colonization projects, and for the inventory of their natural resources. We are assisting the Agency for International Development in this program. IAGS has been supporting mapping operations in Latin America since 1946. During this time, our officers, our engineers, and our pilots have been working day in and day out with their Latin American counterparts. It is hard to imagine any program which has promoted more good will and understanding between the citizens of the United States and our friendly neighbors in Latin America.