30 



RECORD AND RESULTS OP 



The pendulum vibrates nearly at mean solar time, temperature at 71° Fah. 

 The register clock gained daily 2'.9 on sidereal time. 



The "arc" denotes the angle between the extreme right and left positions of the 

 pendulum. 



The geological formation is drift overlying the silurian rocks. 



Pendulum Experiments. 

 Vibrations observed at the Observatory of Harvard College, Cambridge, Massachusetts, July 3 



and 4, I860.* 





G. P. 



3ond, Director of Observatory, observer. 





July 3, 1860. No. 4 faces telescope 



14h07■»29^9 





h. 





and 



swings. 



31.9 



16"06°'39%3 









33.9 





41.3 







R. 



36.0 





43.3 





n^hi 



"15=.2atl2i'5°'npp.tlier.72° 8F. 

 17.2 low. " 69.8 



37.9 





45.3 

 47.4 







19.2 observer, G. P. B. 



R. 





49.4 







21.2 



15 03 34.0at 15M"' \ipp. ther. 71.8 





51.4 







23.2 X 



36.0 low. " 69.8 





53.4 







25.2 



38.0 arc 1.50 





55.4 







27.2 



40.0 





57.4 







29.3 



42.0 





59.4 X 







31.2 



44.0 





7 01.3 







33.2 



46.0 X 

 48.1 





03.4 

 05.4 







L. 



50.1 





07.4 





13 57 



38.2 



52.1 





09.4 







40.2 



54.0 





11.5 







42.3 



56.1 





13.4 







44.3 



58.0 





15.5 







46.3 







17.4 







48.2 X 



L. 





19.4 







50.2 at 13" Sg"- arc 3O.102 



15 04 23.2 











52.2 



25.2 





R. 







54.3 



27.3 



ir 



09 16.3 at 17" 8" 



arc 0.48 





56.3 



29.3 





18.4 







58.2 



31.2 





20.4 





58 



00.3 



38.2 

 35.2 X 





22.4 • 

 24.4 







R. 



37.3 





26.4 X 





14 06 



52.8 



39.3 





28.5 







54.8 



41.3 





30.5 







56.8 



43.3 





32.5 







58.8 



45.3 





34.5 





07 



00.8 at 14" 7"" arc 2.84 



47.3 











02.9 X 



49.3 





L. 







04.8 





\v 



09 51.5 







06.8 



R. 





53.5 







08.8 



16 06 04.0 at 16" 7™ arc 0.81 





55.5 







10.8 



06.2 at 16 9 upp. tlier. 710.7 





57.5 







12.8 



08.1 low. " 69.8 





59.5 







14.8 



10.2 bar. 20.924 inches 

 12.2 at. ther. 740 p. 





10 01.6 



03.6 







L. 



14.1X 





05.6 X 





14 07 



17.9 



16.2 





07.6 







19.9 



18.2 





09.7 







21.9 



20.2 





116 







23.9 



22.2 





13.6 







25.9 



24.2 





15.5 







27.9 X 







17.6 





' Some experiments made .Tnly 2d and 3d, with knife edges No. 3 and No. 1 facing the telescope and swinging, 

 are here omitted. It was found, after reversing the pendulum end for end, that the wooden case interfered with 

 the free action of the pendnlnra (in position, side No. 4 facing the telescope and swinging). The case was screwed 

 closer to the wall, altering by lo or 20 the iuclinati )n to horizontal plane of the faces pn which the knife edges 

 rest when pendulum is oscillating. 



2 Recorded 20.10. s Recorded 16" 



