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.

    44/86 (page 16)
    [ '« ] j. Note the quantity of the arc defcribed by the pendnlum, viz 30 20', difengage the wire in c c, and detach the maintaining power from the frame, and Hide it down to reft upon the point of the ferew o, plate I, lig. 1. The apparatus being refixed ■to the frame, and alfo the wire in the moveable point of fufpenlion, proceed to the fecond adjuftment of the pendulum, by means of the ferew o, plate I, fig. 1, having previoully removed the ball b, to vibrate 84 times per minute, $. The movement being thus prepared for a fecond experiment, let the pendulum be adjufted to perform 84 vibrations per minute, or 120960 in the fpace of 24 hours mean time, and draw another line upon, the ruler as before directed, and note the arc of vi- bration, viz. 30: 20 ; it being requifite that the arcs of vibration ftiould be fimilar to the former, and performed in the fame temperature of air. Thus meafures of length, nearly equal to five feet Englifh meafure, may be obtained from the menfura- tion of time, with much more accuracy than has ge- nerally been imagined; and this independent of the me-