John Beale Bordley, 1727-1804, was a native of Maryland and a lawyer by profession; several works by him are in this catalogue; see the Index.

A manuscript sent to Jefferson in 1790, but no longer in the Library of Congress.

Jefferson wrote to Leslie in connection with this manuscript in a letter dated from New York, June 27, 1790: “ I find among the letters to m( ^~ r) Jay, one from m( ^~ r) Coxe on the subject of the vibrating rod thought of by you for a standard of measure: and I have received from m( ^~ r) 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 utility; so that if I can have your leave, I mean to propose in my report to adopt the rod in preference to the pendulum, mentioning 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. m ( ^~ r) Coxe’s letter to m( ^~ r) Jay seems to imply that you had communicated your idea that I might avail myself of it in the subject referred to me; but 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 . . . ”

This was acknowledged by Leslie in a letter dated from Philadelphia, July 1, 1790: “I was this day honour ^d with your favour of the 27 ^th ult, in which you are pleased to express your satisfaction with respect to the vibrating rod which I proposed as a standard of measure--I shall think myself still further honour ^d, and you have my hearty consent, that you report the same to Congress as the standard of measure for the U. S. I would just further beg leave to observe that since writing the piece you refer to I have been informed by M ^r Patterson Professor of Mathematics in the University here, to whome I mentioned the project, that in the vibrating rod, the center of oscillation is not strictly and Mathematically at 2/3 of the lenght [sic] of the rod from the end or point of suspension, that this is the case only on the supposition of the rod being a mere inflexible line. He however assures me, upon making the calculation that the error in any rod which would be used for this purpose would be totally insensible. A rod for instance of 40 inches long and 4 tenths of an inch in diameter would have the distance of its center of oscillation below 2/3 of the lenght [sic] of the rod only 1/2000. part of an inch or 1/8000. part of the whole length a fraction scarcely within the power of a Micrometer to measure, and may therefore be Safely neglected. Any assistance which it may be in my power to render respecting the above scheme or any other in which you may be pleased to employ me, you may be assured will be always at your service.”

In his Report on the subject of establishing a uniformity in the Weights, Measures and Coins of the United States, July 4, 1790 [see no. 3760], Jefferson referred to Leslie’s proposal: . . . In order to avoid the uncertainties which respect the center of oscillation, it has been proposed by m( ^~ r) Leslie, an ingenious artist of Philadelphia, to substitute for the pendulum, a uniform cylindrical rod, without a bob . . .