Rev. C. *S*. Lyman on the Pendulum Exj)eriment 



403 



periments, an arc of vibration of about seven feet, but in his 

 later ones, of one or two feet only. Mr. B. appears to have taken 

 much pains to note the amount of elliptic motion which the pen- 

 dulum acquires, and applied to the observed angular motion of 

 the plane of vibration certain corresponding correctionSj to ob- 

 tain his tabulated results. 



The following table contains the observed rate of motion, and 

 other particulars of the experiments, at the several places named. 

 We regret that the results of the experiments of Prof. Horsford, 

 at the Bunker Hill Monument, are not within our reach. 



Place. 



Bristol, Eng., 

 (T. a Bunt,) 



a. 





g"f > 



^ Cm 



3 



W4 O 





I ^ c 



53 ft.,Sft. 12097 



11-945 



Dublin, . . . 



York 



(J.Phaiips,) , \ 



Geneva, Sw., . . 

 (Dufour 6l Wartrannn) 



New York City, . 



Providence, R. I, . 



tN^e^v Haven, Ct^ , 



« 



35 ft. 



4ft. 



PC.. 



<d - o 



n'763 



=J CI 



5127 



I.- 



^ 



11-677 



Uin. 11*651 

 short 11-750 



ti 



« 



f< 



u 



u 



hours 

 26i. 



a A 



S7 



4 ft. 11-900 12-073,53 23 



4 



326i 



X H 



Mean of preceding 

 with additional ex- 

 periments. 



Corrected for ellipticit j 



52 

 66i 



U 



9 ft. 

 97 



14 ft. 13-12 

 18 in. 11-94 

 lift. 11-848'10-856 46 12 



12-163 53 58 



<t 



5 ft. 



U 



10-522 



9-733 9-815 



44 



40 44 



9-956 10-03041 49i 



41 trials uncorrected 



for ellipticity. 

 (Galbraith and Haugh- 



ton.) 

 4 trials. 

 4 " 



9 

 9 



4 

 4 





vreight l^^lbs, 

 E. and W, 



N, and S. 



(Prof. Loomis.) 



16 trials, (Profs. Cars- 



171 



... well and Xorton.) 

 Is ft. ( 9-970l 9-928'41 18i! 18 ! 16 trials. 



The calculated motion per hour in the fifth cokimn, is the ac- 

 tual angular motion of the earth, considered as around the verti- 

 cal, in one hour of mean solar time, and of course is somewhat 

 greater than the product of 15° into the sine of the latitude, 

 which gives the motion in one hour of sidereal time. 



From this table it will be seen that the observed rate of mo- 

 tion of the plane of vibration per hour, as nearly coincides with 

 the product of the hourly motion of the earth on its axis into the 

 sine of the latitude of the place as could reasonably be expected, 

 considering the many obstacles in the way of accurate results. 

 Some of the observations noted in the table appear not to have 

 been very skillfully conducted, particularly those at York, where 

 the ellipticity sometimes amounted to three or four inches for the 

 Giinor axis, and was not considered measurable unless it exceeded 



^H mm ^i_ _■ ^^M ^ ^ B H ■ B 



one-fourth of an inch. 



observations was accordingly very great. 



tb 



expe 



pendul 



A' 



