ig4< Sir George Shuckburgh Evelyn's Endeavours 
number the vibrations without affecting them, I dropped the 
idea for that time. I learnt, however, some time afterwards, 
that Mr. John Whitehurst, a very ingenious person, had been 
in pursuit of the same object with better success, and had con- 
trived a machine fully corresponding to his expectations and 
my wishes. This he afterwards explained to the world, in a 
pamphlet, entitled, “ An Attempt to obtain Measures of Length, 
“ &c. from the Mensuration of Time, or the true Length of 
c< Pendulums published in 1787. Mr. Whitehurst having 
therein done all that related to the standard measure of length, 
and suggested that of weight, it appeared to me that it remained 
only to verify and complete his experiments. 
(§.3.) For this purpose, by the kind assistance of my friend 
Dr. G. Fordyce, who, at Mr. Whitehurst’s death, had pur- 
chased his apparatus, I was furnished with the very machine 
with which Mr. Whitehurst had made his observations. I 
also procured to be made, by Mr. Troughton, a very excellent 
beam-compass or divided scale, furnished with microscones and 
end. Mr. Arnold made me one of his admirable time-keepers, 
in order to carry time from my sidereal regulator in my obser- 
vatory, with which it was adjusted, to the room wherein I had 
fixed Mr. Whitehurst’s pendulum; and who, having taken a 
journey from London into Warwickshire, was so good as to 
temperature was about 6o°, first to examine the length of the 
pendulum ; when, to my great mortification, I found that the 
sure : as also a very nice beam or hydrostatic balance, sensible 
with the T ^3. of a grain, when loaded with 61 b. Troy at each 
assist in the beginning of these experiments. Thus equipped, 
I went to work in the latter end of August, 1 796, when the 
o$: 
