 Stephen, you're standing in front of a relatively old map. Tell us a little bit about this and what the Neptune was designed to correct. Well, this is a map from the late 1740s by John Thornton, and it shows northeastern North America. And I think you can see, just by glancing at it, that it doesn't look much like a modern map at all. We have lines of latitude on here, but we don't have longitude. And so the geography of the area shown on the map is somewhat distorted. And to understand the revolution brought about by the Atlantic Neptune and the surveys that led up to the Atlantic Neptune, you've got to see this map of the 1740s, and then when you see what the surveyors did for the Atlantic Neptune, you get an understanding of the great revolution in surveying and mapping that took place in the 1760s and 1770s. Stephen, we're standing in front of a map from the Neptune. Now tell us how this compares to the one we just saw. Well, this is one of the most magnificent charts from the Atlantic Neptune, dates to about 1780. And as you see, it covers the same geographic area as we saw in the Thornton map, but you can immediately recognize that this looks like a modern map. We don't have that great distortion of geography that we saw in the Thornton map. The revolution that's occurred here is not only do we have accurate reading of latitude, but we now also have reading for longitude. And this was done through using telescopes and comparing observations here in northeastern North America with observations back in London, which allowed the establishment of longitude. And so we could get the east-west distance correct on this map, as well as the north-south distance. And that allows the geographical shapes to look as they should do to us today. And so I think this is an instantly recognizable part of northeastern North America, whereas the Thornton map, you can see that it was somewhat distorted. And talk about the genesis of the Neptune. How did it start? Was it a commission? How did it begin and who paid for it? It's quite a long process in the development of the Neptune. It began in the early 1760s during the Seven Years War. The British were fighting the French in northeastern North America. And after they captured Quebec, they realized they needed accurate maps of the St. Lawrence Valley. And they did a great survey of the St. Lawrence. And then after the peace treaty in 1763, when they took over former French and Spanish territory and then controlled the territory from Hudson Bay down to the Gulf of Mexico and from the eastern seaboard to the Mississippi River, they realized they needed maps of these vast areas that were now under British control. And so surveys were instituted from Labrador and Newfoundland right down to the Gulf of Mexico to figure out what they now had. Let's talk a little bit about the people who made the Neptune. There were two principal characters. One was Samuel Holland. The other was Joseph Frederick Wallet de Barre. And we're looking at a reproduction of a painting of de Barre here. They were both army officers. They were both from the continent of Europe. Samuel Holland was from the Netherlands. De Barre was from Switzerland. The outbreak of the Seven Years War, Britain, was short of army engineers and surveyors. And so they recruited actively on the European continent and brought these two surveyors into the Royal American regiment and they were promptly shipped out to North America to begin the survey and mapping work. Holland was the more senior officer and de Barre his junior. They had divided responsibilities for the surveys. Holland did most of the surveying work from Quebec round to Newport, Rhode Island. De Barre did Nova Scotia, surveyed Nova Scotia. We know more about de Barre because it's de Barre who gets the charts published, engraved and published in London. So de Barre's name is on the Atlantic Neptune rather than Samuel Holland. Stephen, the charts in the Neptune were not just used for scientific purposes. There was economic and military uses for them as well. Talk about that for a bit. That's correct. We're looking at a map here of Egmont Harbour on the coast of Nova Scotia. And this is one of de Barre's surveys. He did Nova Scotia. He was working for the Admiralty. So he was most concerned about providing accurate charts of harbours and potential harbours along the coast of Nova Scotia and also identifying areas that could be used for the fishery, particularly the cod fishery which is, as you know, so important in the Gulf of Maine on the coast of Nova Scotia. So this wonderful chart is showing several important pieces of information for a mariner. Not only do we have the very careful delineation of the coastline, but we also have soundings so a mariner would know the depth of water. And at the bottom of the chart you can see a coastal profile that's been incorporated into this particular plate from the Atlantic Neptune. So if you're at sea, a mariner could see the headlands and identify where he was along the coast. So this particular map from the Atlantic Neptune shows these different types of information, which will be of use to a naval officer or indeed a commercial mariner working along the coast. This map also has this charming vignette in the centre of the map and it's showing a settler's clearing and a log cabin and gives some sense of the beginnings of European settlement along this coast. It has no really geographical or military information but it is just sort of enlivening the chart and adding a sort of human dimension to the overall image. And this chart is in black and white and some of them are colour and those were hand coloured? Yes, these would have been coloured with a hand wash and so you can get various shades of green or indeed brown that would be applied to the land areas. Talk a little bit about the process from going from the original sketches that they made in the field to getting it printed in the Neptune. Well, when both surveyors went back to London just before the outbreak of the American Revolution they took back their manuscript maps, which were very detailed. These were more than just sketches, they were extremely detailed and large scale maps. And Samuel Holland gave his maps over to De Barre and De Barre began the laborious process of turning a manuscript map into an engraved chart. We're very fortunate to have one of the copper plates on display here at the exhibition. It's been lent by the Massachusetts Historical Society and shows this large engraved plate that would have been used in the press to print the map. This particular plate is showing Falmouth, so it's of direct local interest. Falmouth, of course, was the predecessor of modern Portland. The plate itself is showing the last state of engraving. They would have begun with quite a basic outline of the coastline and as they got more information, particularly soundings, they added information. So there are several states to these charts. I think on display here we have two states from the Falmouth chart but other parts of the coast went through even more states. As they got more information, it was applied to the copper plate and so what we're seeing here with this copper plate is the very final addition or the final state of the plate and all the information that amassed and put on the plate at that time. Steve, we've talked about the detail in these charts and maps. We're standing in front of one of the main coast. Talk about the detail that's shown here. If you were to look at the earlier charts such as the Thornton map, the main coast really defeated those map makers and on the main coast, particularly Casco Bay with its very complex geography of peninsulas and islands and reefs and islands and so forth and so it was very crudely represented on the earlier maps and when the surveyors, and this is actually Holland and his deputy surveyors, came into the Gulf of Maine, they were headquartered in Portsmouth and spent several years surveying the main coast and the reason it took them so long of course is the complexity of the coast. They couldn't just leave bits out or represent it crudely. They were very aware that they were producing a scientific hydrographic chart and so they were meticulous in what they were recording on the maps and charts and we can see this in the spectacular example of Casco Bay. This is a chart that actually belongs to the Ocean Map Library and we're very fortunate to have it here in Portland showing of course Casco Bay, Falmouth and so forth. Does a chart or a map with this detail sort of change the people at the time, change their view of the world? These maps were being produced during the American Revolution. They started to be printed in 1775, 1776 and so it's unlikely that the local people would have seen these charts. These were in the hands of the Royal Naval Officers who were imposing a blockade on the New England coast and the last thing they wanted was the Patriots to get their hands on this latest scientific knowledge of the rebellious coast. So something that's highly classified then? Yes, it certainly was. There is a remarkable story in that one of the Naval Officers working for a day bar charting the Gulf of Maine was unaware that the Revolution had broken out and he put into Machias' harbour to wood and water take on supplies essentially and he was captured by the Patriots. It's a very well known incident in the beginnings of the American Revolution. So he was imprisoned and he took all his personal belongings and maps with him and then he was exchanged for an American prisoner and came back to the British side with all his maps with him and there's a wonderful letter from one of the Patriots' leaders in Machias saying oh gosh you know we've let him go back with all those charts and we should have really kept the charts so it was only after the fact they realised that he had all the scientific information with him which he then brought back to the British side. The charts in the exhibition are over 200 years old. Do they still have value today? They most certainly do. They're used by geologists, by archaeologists and indeed by geographers. The geologists find them of great use because they provide our first baseline data for the coastline and the sea level at that time in the 1760s and early 1770s. They're very scientifically accurate and so we can now measure how the land surface or the sea has changed from that period over the past 250 years. Archaeologists use these maps because they often show some human information along the coast. There will be some settlement information and archaeologists have used the maps to find the foundations or indeed existing houses from that period. They're shown on the charts and so they're in a sense a guide for the archaeologists looking for settlement along the coast. Geographers such as Rosemary Mosier have used them to reconstruct what Portland looked like 250 years ago. This particular creation is showing Debar's chart of Falmouth overlaying over a modern aerial photograph and so we can see the outline of the Portland neck or Falmouth neck and the coastline as it was 250 years ago and then the modern infill in Portland Harbour and in the Back Bay area. And the exhibit is here in the Ocean Map Library for how long? It's here until August 14th and it is well worth a visit. It's a magnificent display of maps and there's a number of very fine main maps on show. It's as good as an exhibition of the Atlantic Neptune that I've seen.