I've been doing some research back before the 1840 era in land records, and I've found the term "perches" often used. The United States, although independent from Great Britain, still held on to many of the traditions of the home country. This article from the The Adams Sentinel, Gettysburg, Pennsylvania published in October, 1830, shows the use of the term, "perches."
So far, my research has shown that a perch is basically the same as a rod or 16.5 feet. One rod = one perch, easy? A perch is also the same as a pole. So, in the above advertisement, 105 perches = 1,732.5 feet. So, it couldn't be measured in acres? It was an odd shaped piece of ground?
1 Acre = 43,560 square feet
1 Acre = 160 square rods
1 Acre = 160 perches
1 Acre = is about 208 3/4 feet square
I'm still having trouble visualizing this piece of land, but I think I'm a little closer!