42 



MAGNETIC INTENSITY, FERN ROCK OBSERVATORY 



January 17, 1854. Fern Rock Observatory, Tan Rensselaer Harbor. 



A. 67 suspended. E-xperiments of vibrations. (From right to left.) 



Time by pocket chronometer. 



b'^ 58"" 37^3 

 52.9 

 59 08.0 

 23.8 

 38.7 

 54.5 



6 00 09.9 

 25.9 

 40.2 

 55.8 



46 

 47 

 48 

 49 

 50 

 51 

 52 

 53 

 54 

 55 



Time by pocket chronometer. 



6'' 10- 



12 



10^8 

 26.3 

 41.4 

 57.0 

 12.7 

 28.0 

 43.3 

 58.4 

 14.0 

 29.6 



Time of 45 double vibrations. 



11" 



33^5 

 33.4 

 33.4 

 33.2 

 34.0 

 83.5 

 33.4 

 32.5 

 33.8 

 33.8 



Mean ll"'33^45 



Arc at beginning 4° 40'. 

 " end 1 28 



Temp. 50°. 



Time of 2 vibrations 

 15^410. 



The vibrations from left to right could not be observed. 



January 18, 1854. Fern Rock Observatory. 



Experiments of vibrations. (From right to left.) 



Time by pocket chronometer. 



5'> 30° 



31 



32 



33 



Time by pocket chronometer. 



5'^ 43° 



44 



45 



46 



37^5 

 53.8 

 08.8 

 23.9 

 39.8 

 54.0 

 10.8 

 25.8 

 41.8 

 57.0 

 12.5 



Time of 50 douhle vibrations. 



12'" 54.5 

 55.0 

 54.8 

 54.6 

 55.4 

 54.0 

 65.5 

 54.8 

 55.3 

 55.0 

 54.5 



12 54.81 



Arc at beginning 4° 40'. 

 " end 1 12 



Temp. 68. 



Time of 2 vibrations 

 15^496. 



January 18, 1854. Fern Rock Observatory. 



E.xperimcnts of vibrations. (From left to right.) 



Time by pocket chronometer. 



5" 30™ 50 \ 8 

 31 06.7 

 22.0 

 36.9 

 52.9 

 08.0 

 23.8 

 39.2 

 54.8 

 10.3 

 26.0 



32 



51 

 52 

 53 

 54 

 55 

 56 

 57 

 58 

 59 

 60 

 61 



Time by pocket chronometer. 



5'' 43" 

 44 



46 



46^7 

 02.0 

 18.4 

 32.7 

 49.0 

 04.8 

 20.0 

 35.3 

 51.0 

 07.0 



99 9 



Time of 50 double vibrations. 



55^9 



55.3 

 56.4 

 55.8 

 56.1 

 56.8 

 56.2 

 56.1 

 56.2 

 56.7 

 56.2 



12 56.15 



Arcs and temp, as before. Time of 2 vibrations 15^523. 



(Dr. Hayes assisted in these observations.) 



