An attempt toward obtaining invariable measures of length, capacity, and weight, from the mensuration of time / [John Whitehurst].

  • John Whitehurst
Date:
1792?]
Catalogue details

Licence: Public Domain Mark

Credit: An attempt toward obtaining invariable measures of length, capacity, and weight, from the mensuration of time / [John Whitehurst]. Source: Wellcome Collection.

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    fure, whofe vibrations in a given time, confift of whole, and divisible numbers; and yet fuels lengths and vibra- tions only, will anfwer the purpofe required. Then fince the affumed length of the feconds pen- dulum in the latitude of London, is 39,2 inches; and according to the refult of the following theorem, pendulums which vibrate 4a and 84 times in a mi- nute coincide with Englifh meafure, viz : 422 : 602: : 39,2: 80 1 , c > Inches. : 6<T: • 39.2: 20 j Such are the lengths and vibrations of the two pen- dulums applied in the conftrudlion of the apparatus, and the difference of their lengths is the meafure pro- pofed to be obtained, viz. 80—20=60 inches; and this, independent of the mechanical operations re- quifite to afeertain the center of ofcillation, or the true length of pendulums. The refult of this reafoning would have been ftridlly true, provided the ball were infinitely final], and the aflumed length of the fecond s pendulum were alfo true, viz =39,2 inches. But fince the accu- D racy