E xperime7its on the Vibrations of Pendulums. 281 



It hence appears, that when a pendulum is suspended by a 

 flexible string, a heavier weight and a consequent greater arc of 



vibration, causes the clock to lose. 



The following are the dimensions of the springs which were 



experimented with : 



Number. Breadth. Thickness. 



1 - -350 inch - -001 inch. 



2 - -390 - - -002 



3 - -395 - - -003 



4 - -395 - - -004 



5 - -400 - - -005 



The pendulum being suspended by the weakest spring, No. 1, 

 the times were noted as before, in which the arcs of vibration 

 were reduced from 2° to 1^, and from P to ^°, no maintaining 

 power being applied. 



Arc reduced from 9P to 1° in Ih. 5Sni. 

 Do. do. 1 57 



Do. 1 to i 2 8 



Do. do. i 2 10 



With the same spring, and a maintaining power of 41b. loz. 

 and 21b. 2oz., the following arcs of vibration and rate of the clock 

 resulted from two consecutive days, the effective length of the 

 spring being "92 inches. 



Weight. Arc. Rate. 



41b. loz. 2° 3' -9s. -6 



2 2 1 30 -6 1 



The pendulum heing suspended with spring No. 2, and clipped 

 at -92 inch, without maintaining power, the arcs of vibration 

 were reduced as follows : 



From 2° to 1° in 2h. 20m. Os. 

 Do. 2—1—2 20 44 



Do. 1 — i — 2 26 



Do. 1 — i — 2 26 



as 



power, I found as 



We.„ 



Arc. Rate. 



41b. \oz. ' 2° ^ -Os. -2 



2 2 1 36 +2-5 



Vol. xsxTii, No. 2.— July-October, 1839. 



36 



