Col: Lane informs me1 that Mr. Hassler has selected for the scite of an Observatory which will have relation to the survey of the Coasts, the square North of the Capitol, which includes the spot on which the House formerly Gen. Washington’s stood; and that Mr. H. considers it necessary that the entire square should be exclusively appropriated to the object. I can have no doubt of the intrinsic fitness of the selection. But considering the probable value of that square, and the possible inconveniency of alienating so much ground in that situation from other uses, I have written the two letters inclosed, which I leave unsealed, for your perusal, to be sent after it, according to their directions.2 You will see that I have taken the liberty of asking your aid in obtaining the means of a safe and proper decision, among the best of which I include the remarks and opinion you may yourself form on the subject. Should the request interfere in the least with the time of your meditated excursion from Washington Be so good as to put this into the hands of the Secy. of State who I hope will be able to answer the purposes of it without much avocation from his more important objects. Accept Dr. Sir my cordial esteem & best wishes