[65] In regard to Braddock's movements on July 1st and 2d, the writer desires to offer a plausible solution of some statements in Orme's journal that have led to no little confusion and inaccurate assertion on the part of those who have written on the subject.
"On the first of July," says Orme, "we marched about five miles, but could advance no further by reason of a great swamp which required much work to make it passable." This bivouac, as has already been said, is undoubtedly on the farm of John Truxell. The army, which was close at the heels of the advance or working party, had to halt there till a corduroy road could be thrown across the swamp, a process that required time.
"On the 2d July," continues Orme, "we marched to Jacob's Cabin, about 6 miles from the camp." Notice the words "from the camp." The preceding stop was then a _bivouac, not a camp_. The camp referred to was the encampment one mile on the east side of the Youghiogheny, at Stewart's Crossing. This day's march would be about one mile, and the place of encampment Jacob's Cabin. The two halting places were evidently both on the east side of Jacob's Creek. What is commonly known as the Great Swamp Camp was only the bivouac to which reference has been made.
This view of the matter seems, however, not to have been taken by any of the cartographers: but in estimating the value of maps one must, of course, consider whether the author's first-hand knowledge, as well as his borrowed data, be trustworthy or not, and must also take into account the purpose for which the map was made. Professor Channing has pointed out among other things that, while "a lie in print is a persistent thing," one on a map is even less eradicable, and for three reasons: (1) because the historical evidence on maps is liable to error, and an error once made is copied by other cartographers, with the result that a false impression frequently continues through centuries; (2) because the topography is often wholly wrong, especially on the earlier maps, a fact that is too commonly overlooked by historians; (3) because, as our own national history has abundantly proved, boundaries are frequently delineated imperfectly, inaccurately, and without basis in fact. In a word, Professor Channing thinks that maps are often taken too seriously, that the historical information given by them is liable to error, and that they simply raise a presumption.