DEAR SIR,--Yours of July 30th came to hand yesterday. It has consequently loitered somewhere two posts. I am glad to learn the prompt aid you have afforded the Treasury department. To let you further understand the importance of giving all the aid we can, I pass through your hands my letter of this day to Mr. Gallatin, with those it encloses, which I will pray you, after perusal, to seal and put into the post-office. In the support of the embargo laws, our only limit should be that of the appropriations of the department. A letter of June 5th from Mr. Pinckney informs us he was to have a free conference with Canning, in a few days. Should England get to rights with us, while Bonaparte is at war with Spain, the moment may be favorable to take possession of our own territory held by Spain, and so much more as may make a proper reprisal for her spoliations. We ought therefore to direct the rendezvous of our southern recruits and gun-boats so as to be in proper position for striking the stroke in an instant, when Congress shall will it. I have recommended this to General Dearborne, as I now do to yourself. Mr. Fulton writes to me under a great desire to prepare a decisive experiment of his torpedo at Washington, for the meeting of Congress. This means of harbor-defence has acquired such respectability, from its apparent merit, from the attention shown it by other nations, and from our own experiments at New York, as to entitle it to a full experiment from us. He asks only two workmen for one month from us, which he estimates at $130 only. But should it cost considerably more I should really be for granting it, and would accordingly recommend it to you. This sum is a mere trifle as an encroachment on our appropriation. I salute you with affection and respect. TO THE SECRETARY AT WAR. MONTICELLO, August 12, 1808.