Mrs. Moncures 26th Feb. 1768
Since I parted with you, I have upon reflecting on the Bounds proposed in my Memorandum for the Ohio Grant, apprehended that in one particular I am wrong. I have mentioned "Beginning on the River Mohongahaly where the Pensylvania Line crosses the said River; and runing with the Pensylvania Line a due West Course to the Ohio River." Now as we are not certain where Mr. Penns five Degrees of Longitude will end, this description may be disadvantageous to us. If his five Degrees of Longitude reach over the Ohio upon extending his lower West Course, then I am right; but on the contrary, if his five degrees of Longitude are out before his lower West Line reaches the Ohio, then I apprehend Mr. Penn must run a North Course from the end of his West Line; which will strike the Ohio River much higher up than to continue the West Course would do, and take in some very valuable Lands that the Bounds before mentioned would leave out. It is indeed said that the five degrees of Longitude on his lower West Course will reach over the Ohio; but as this is not absolutely certain, we should be cautious in our Descriptions. I therefore think it will stand much better thus, "Beginning on the River Mohongahaly where the Pensylvania Line crosses the said River, and running with the Lines or Boundaries [of] Pensylvania to the Ohio River &c" as before, this will answer in either Case. As I desire Mr. Daniel to whose care this is directed to [leave] immediately, I hope it will come to your hands before you dispatch your Letters to England; for I think the Alteration very material, for some other Reasons which I have not now time to mention.
[P. S.] Or as Mr. Penn's Bounds are yet so uncertain, perhaps the Boundaries of a Grant to the Ohio Company would be better expressed as follows
"Beginning upon the East side of the River Ohio or Allaghany where the Pennsylvania Line crosses the said River, and running down and with the said River Ohio to the Mouth of the Great Conhaway River, alias New River or Woods River, and up and with the said Great Conhaway River to the Mouth of the Great Briar River, from thence by a streight Course to the nearest part of the Boundaries of Pennsylvania, and with the Boundaries or Lines of Pennsylvania to the Beginning upon the Ohio River."
All that Country or tract of Land bounded on the West and North West by the Ohio or Allaghany River; on the South and South West by the Great Conhaway River, otherwise called New River or Woods River; on the East and South East by the Green Briar River and the Allaghany Mountains, on the North and North East by the Mohongahaly River and the Boundaries of Pennsylvania to the Ohio or Allaghany River.