I yesterday received your Favor of the 21st on the Road, and thank you much for the Ordinance respecting the Royal Corps of French Engineers. I cannot give it a serious perusal at this time, but doubt not, I shall find in it several interesting and useful hints. I hope the Gentlemen you allude to, will be of great service, but I am totally unacquainted with the rank they held in France. We are extremely deficient in our knowledge in this important branch of War, and it is not to be wondered at.

As soon, as I had authentic information of Genl Prescots Captivity, I wrote to Genl Howe and proposed to exchange him for Genl Lee.1 I have received no Answer to the Proposition, though My Letter must have got to hand some days before the Fleet sailed from the Hook. Most probably, he will take some time before he agrees to it, having declared him unexchangeable in one instance, and Only argumentatively to be in the same predicament of Other Officers, in Another. His Objection, most likely, arose from a Supposition we should never have a Major Genl in our possession.

I was provided with the Cartel settled between France & England before the reprinted Copies came out. It is much to be wished One could be settled on liberal & equal Terms, but at present all further Negotiation on the Subject seems at an end. From what I could learn, the Gentleman appointed on the part of Genl Howe, considered the mode proposed by Congress & which was acceded to, entirely competent, as to the mere Exchange of prisoners. Your Observations about Rank are not without weight, but from the present disposition of the Enemy there is little reason to expect, especially as they have a sort of Cartel to found their claim upon, they’l yeild a Single Jot. I am in great Haste Yr Most Obedt Sert