-^u. 



\ J 



I 



p 



p 



-Rev. C. S. Lyman ^ the Pendulw^ Experiment 



405 



series.?<if 

 11 J *i. \ 



motion of the apses of the.pjfpse was least^ and ■.st)metimes even 

 f^^u ^1^.. j:„__.i_. •„ t^iffti to the effects of 4hat motion. 



/a<?e and with the 

 same pendulum, there is ob^Sed, as was remarkld before, con- 



Mr. Bant^ilfenlts for the hoaljy rate of mo- 



from each other — though his 



in diiferent trials. 



tion sometimes differ nearl 



experiments appearfto have beS^very carefully c(iiducted. 



ps at York; present still greater 

 discrepancies. At New Haven the rate of motion per hour in 

 different trials, always fell within half a degree^of the mean, as 

 will be seen from the following table, which presents more in 

 detail the observations of which some general results were given 

 m a previous paper. 



Tinj 



e. 



Part of azi-; Length of 1 



muthal cir- arc of vi- 

 de passed bration at 



Minor 



over. 



1. 



2. 

 3. 

 4. 

 6. 



6, 



7. 



8. 



9. 

 10. 

 11. 

 12. 



13. 

 14, 



15. 

 16. 



111111. 

 41-5 



36-3 



184-2 



60-8 



61-5 



63-0 

 l'72-8 

 29-0 

 61-5 

 29*5 

 95-2 

 17-3 

 23 7 

 36-3 

 49-7 



Length 

 of arc j axis of 



Direc- | Motion of Motion of 

 tion of plane of vi- apses of 



bration per ,the ellipse 



motion 





o o 



0-7 



0-20 

 0-6 

 0-80 

 0-10 



0-10 

 10-20 



90-120 

 90-95 



130-140 



40-45 



170-185 



130-133 



41-45 



89-95 



0-8 



inches, inches. 



48-0 

 55-0 

 50-8 

 SG-6 

 40*4 

 40-6 

 4 GO 

 440 

 43-4 

 44-8 

 48-6 

 390 



46-0 

 43-0 



2S'0 

 11-6 

 27-2 

 6-0 

 17-4 



17-4 



18-6 



7*2 



26-8 

 18-6 

 29-8 

 122 

 34-4 

 300 

 26-0 

 20-6 



i 



m. 

 0-02 

 -01 

 •06 

 '10 

 •20 

 •10 

 ■SO 

 ■16 

 '12 

 '04 

 •10 

 •08 

 •08 



•00 

 •06 

 •06 



R 



R 

 R 

 R 

 L 

 L 

 L 

 R 

 R 

 R 

 L 

 L 

 B 



■ 



R 

 L 



dec. 



9-92 



lO'OO 



9-87 



9-75 



9-52 



10-41 



10-34 



9-75 



10-17 



9-46 



10-28 



10'13 



9-92 



9-66 



per hour. 



+ 

 + 



+ 



+ 



+ 



o 



0-01 



•01 

 •02 

 •03 

 •06 

 •03 

 •OS 

 •04 

 04 

 01 

 04 

 02 



03 

 00 

 02 

 02 



Motion of 

 plane cor- 

 rected for 

 cllipticity. 



lO'll 



10-25 



9*90 



9-97 



9-93 



9-'^8 



9-60 



10-37 



10^30 



9-74 



10-21 



9-48 



10-26 



10-13 



9-92 



9-68 



9-97 



997 



The zero of the horizontal circle was nearly in the meridian. 

 The mean rate of motion, it will be observed^ a little exceeds 

 that given by the rule of the sine of the latitude, which is 9^-928, 

 or 90 55' A3'' per hour of mean solar time. The number of ob- 

 servations made was not sufficiently great to eliminate entirely 

 the effects of errors of^ observation, or give anything more than 

 ^n approximate mean resul^. 



sii 



dency 



row ellipse, instead of a straight line, has been remarked by all oD- 

 servers ; and the degree of eMipticity has, it is believed, been uni- 

 formly observedf'to increase during the progress of the experiment, 

 at l,^ast until itis arc of vifiration had become very short. The 

 ellip:icity may be conside^d of two kinds, the necessary, and 

 the accidental. 



Th'i slight eUipticity which must necessarily be given to the 

 motion of the-^ndulum by the rotation of the earth itself, has 



Second Seeies. y'oL XII. No. S6,- 



»,- 



i". 



■Ifov., 1851. 



£2 



V 



