It is long since any occasion presented itself of addressing a letter to you. I avail myself with pleasure therefore of that offered by the papers I now inclose you. they were intended for the society as I judge from the superscription. a long journey soon after their reciept from which I am but just returned, prevented my earlier transmission of them. I was very sensible of the solidity of the difficulties, stated in your letter of Jan. 10. as opposed to our idea of endeavoring to introduce a voluntary uniformity of measures & weights. the only succesful example of that in my recollection is in the introduction of Botanical names, & even that has not extended to the lower class of people. of the very extensive reformations attempted in France, and with the aid of governmental authority, that alone of measures & weights will probably succeed. their new divisions of time, & of the circle, new names to their cities Etc are already nearly fallen into desuetude. their measures & weights will be continued of necessity, because of the infinitely perplexing varieties they had before in the different parts of the kingdom, so as to be entirely unintelligible to one another. perhaps the most probable course is that the world will in the long run adopt their system, using the pendulum as a common term of comparison between that & their municipal system. I presume mr Voigt is going on with my clock. perhaps you may be able to have sent with that the artificial horizon of your invention which you were so kind as to mention to me formerly, so that I may include both in the same remittance. accept the assurance of my constant esteem & respect.

Th: Jefferson