Your favor of Apr. 10. was recieved in due time as had been some time before the 6. barrels of water proof cement from you. I had already laid in as much Roman cement as did my 2d & 3d Cisterns, with a barrel surplus towards the 4th and last. the 2d and 3d were done under the superintendance of mr Coffee, and with perfect success. we opened a barrel of yours and he tried several fair and careful experiments according to the directions you had given. in every instance this cement dissolved on being put into water, while we saw that the Roman became immediately set and hard on being put into water. I have still one cistern to finish, but after the unsuccesful trials by mr Coffee who understood the manipulation of these things so much better than I do, I am afraid to risk it with yours. it would be giving up a finishing of the success of which we are certain for one which our experience teaches us to doubt at least. there is no call at the University for any thing of the kind nor could I recommend to that what I am afraid to try myself. in this state of things I will make any disposition of the 6. barrels you will direct. but seeing no probability of their being employed in this neighborhood, I think the best would be to send them down to you, which I will do if you think so also. I do not know whether you continue your pottory. if you do I will request of you 50. pots for the sea–kale such as you saw here, which indeed are made on the exact model of mr Wickham’s. if delivered packed in hogsheads to the order of Colo Peyton, he will, on sight of this letter, pay for them. accept the assurance of my great esteem and respect.

Th: Jefferson