I find among the letters to Mr. Jay, one from Mr. Coxe on the subject of the vibrating rod thought of by you for a standard of measures: and I have received from Mr. Madison a manuscript pamphlet of yours on the same subject. Congress having referred to me to propose a plan of invariable measures, I have considered maturely your proposition, and am abundantly satisfied of it’s ability; so that if I can have your leave, I mean to propose in my report to adopt the rod in preference to the pendulum, mention[ing] expressly that we are indebted to you for the idea. Should they concur with me in opinion it is possible that in carrying it into execution we may have occasion to engage your assistance in the proper adjustment of it, as well on account of your abilities in that line generally, as for the peculiar interest you would feel in the success of the experiment. Mr. Coxe’s letter to Mr. Jay seems to imply that you had communicated your idea, that I might avail myself of it in the subject referred to me; bu[t] I think it justice to ask your express permission, and that you will be so good as to give me an answer by return of post. I am Sir Your most obedt. humble servt.,