I’ve just finished the North Atlantic crossing of the little schooner at the center of my microhistory-in-progress. Even with the irregular zig-zags representing a sailing vessel’s progress along a track only discernible from a zoomed-out view, the plot, with its crisp, thin black line and red dots at five-day intervals, the visual rendering of this routine death-defying course through some of nature’s most powerful forces looks so precise, so definite.
That is an illusion; the visual representation both reveals and obscures the truth. The historical records upon which the plots are based are the logs of the commander and the master—two different people, each keeping his own journal, such that slight discrepancies are common and irreconcilable inconsistencies occur from time to time. Eighteenth-century ships’ logs are written in table form with labeled columns and consistent conventions for recording, in a special shorthand, the winds, the courses, the day’s run in miles, the estimated position, and the most important occurrences on board that day—sail changes, damage, sightings of other vessels, sightings of land or soundings of the bottom. The logs are neat and orderly, a utilitarian and quotidian human effort to distill what those who made them assumed would be most worth revisiting later—something fixed, in ink on paper, unlike the fickle memories that would not stick in the mind, of experiences so much larger than what was written down but gone forever as soon as they happened. The logs are yet another human attempt to impose order on chaos, written so carefully by someone wedged into a corner of creaking wood, making legible marks on a page by guttering lamp while the vessel that contained him pitched and tossed and rolled and groaned.
The letters and numbers in the log were not only an incomplete record of the day’s reality; they were an imprecise one as well, no matter how skilled the navigator, no matter how benign the conditions in which he worked that day. The compass and the octant, the chip log, and the human hands and brains that worked them all introduced slight deviations from the truth they sought, so that the exact truth—any exactitude at all—remained unattainable. No position ever plotted by an eighteenth-century navigator out of sight of land was exactly where on the surface of the planet his ship was—or, if it was, that was by chance. These navigators knew this. The skill of knowing how much confidence to place in any attempt to determine position was as important as the skill of knowing how to determine that position. Navigators used every means at their disposal to guess at their position—compass heading, corrected for magnetic variation; the angle a celestial body made with the horizon, converted to latitude with the help of an almanac; the speed through the water measured by a chip of wood pulling a knotted cord through a seaman’s hands or floating past the known length of the hull in a certain number of seconds. When currents were detected, they tried to estimate how far, and in what direction, the current might be setting them off course. Cloud patterns, sea birds, and—close to the coast—the depth and composition of the seabed could warn of approaching land. When, as was inevitable, the various techniques pointed the navigator toward slightly differing positions, it was up to his judgment to determine the best estimate. Even now, the positions we call “fixes”—those upon which we have the highest level of confidence—are marked by a dot surrounded by a small circle, because every navigator knows there is no such thing as a fixed point in the sea.
Plotting a voyage from 1768, using a geo-referencing application probably invented a decade ago, forced judgment calls at every point. At the entrance to the English Channel, the wind forced the schooner southward, toward Brest, France. The latitude and longitude recorded for that day put them in Brest, France. We know that’s wrong, but how wrong? We can use recorded bearings to known points, and distances from those points—accepting that those are estimates, made by experienced eyes and judgements, not precise instruments. The plot I made of that day’s run preserves the reality of the southward push, and the approximate location of the schooner’s track relative to the coasts of England and France, and relative to the following segment of the route. I make no claim that the schooner was ever exactly on any point of the track as I have plotted it. To counter the visual illusion that she was, I made notes for each segment, and when I reproduce the image in the book, those notes will be keyed to the red dots, and they will explain the uncertainties, the judgment calls, and how I used the source material to make those judgement calls about those uncertainties.
That these plots are valuable history despite their limitations is beyond question. They illustrate, as the words and numbers upon which they’re based cannot, the reality of crossing an ocean in a vessel that could neither sail anything close to directly into the wind, nor make progress against too high a sea. They remind the observer that, for their own reasons, groups of people routinely sent other groups of people out to sea to face the autumn gales of the North Atlantic from England to America on small wooden vessels sailing against the prevailing winds and currents. It took my little schooner two months to cross the North Atlantic that autumn. Looking at that plot shows you, rather than tells you, why. That’s why it’s worth using all the source material at hand, all the skills and experience I can bring to understanding what that material is telling me, and all the brain work required to make the judgement calls necessary to produce the best interpretation I can out of what I have. The result will never be—can never be—perfect. History is the craft of applying experienced judgment to all the relevant source material we can find. History can never perfectly present the past. That’s not why we do it. We do it because it is far better to have a good approximate idea of where we have been and where we are going than to have no idea at all.