I have duly received your letter of May 10. It is true as you have understood, that Mr. Hassler is ingaged [sic], under an Act of Congress, to make a survey of the Coasts &c of the U.S. and that he procured for the purpose instruments of peculiar excellence. But the survey is not yet commenced, and it is not probable that it will be extended to Virginia during the ensuing summer. You will infer, of course, that neither Mr. Hassler nor the Instruments can be spared for any other service.

A survey of the Potowmac for any distance above its mouth is not likely to fall within the general survey provided for. Particular surveys of York river at least as far as York Town, and of Hampton Roads, have been made under the direction of the Navy Board, by Capt: Sinclair. A copy of his report can at any time be had; and you will be able to avail yourself of any other surveys made under the same direction. Accept Sir my esteem & friendly respects

Isaac Briggs now of the State of Delaware is known to be skilful in every requisite for the most accurate charts. He may perhaps become an auxiliary to Mr. Hassler. If he should not he may claim your attention in selecting an able hand for the contemplated Map.