38 Lovering and Bond on Magnetic Observations at Cambridge. 
Magnetic Table. 
‘Time of Mean ‘Time of Mean 
F | mber Age . pading hi - . | Reading of the “1 
Months. pier aioimdim Deal Bode fr Moxa pecimnmar eo: Scale for Mean agp ee 
observed. Cambridge M. T. Minimum. Cambridge M. T. Maximum. Be 
May 3 6h 26 A. M. 114.523 1h 06’ P. M. 100.208 14.315 
June 10 (omelet is 110.528 1 6) 7st 100.875 9.653 
August 5 (iyeelay 126.564 Ly Ades, KE 115.135 11.429 
September* 5 111.925 |11 36 A.M. 96.452 15.473 
October 5 epeisiy 102.250 3) 0 Se: 94.368 7.882 
\November 3 SOL 111.958 i Spat Coe 95.927 16.031 
December 3 fe} (Ney. 100.767 3 16 «& 92.226 8.541 
January 3 Doge! Mh 3 98.871 3° 26° ee 90.062 8.809 
February 3 Bie nes 99.816 3 16, 16 91.090 8.726 
Means 6a) 7% 108.578 204. vie 97.371 11.206 
The times of the monthly mean minima of temperature for the 
seven months from August inclusive, December being rejected as 
anomalous, range between 4" 56’ and 6" 36’ A. M. so as to be all 
comprised in the space of 1°40’. Similar times for the maxima 
points are included within 2" 20’ from 0" 36’ to 2 56’ P. M. It also 
appears that the times of the monthly means of minimum declination 
for the same months together with May and June, if we leave out 
September, come between the limits of 6" 16’ and 9" 16’ or an inter- 
val of 3 hours, while the times of mean maximum declination, if we 
exclude September, are confined within the limits of 1" 06’ and 3° 26’ 
or 2 20’. All circumstances being considered, these results are 
favorable to the theory which assigns to the daily changes of mag- 
netic declination as precise a dependence on solar time as can be 
claimed for the corresponding variations of temperature. As far as 
coincidence of time between two phenomena proves one to be the 
cause and the other the effect, the daily oscillations of the magnetic 
meridian are as clearly referrible to the sun’s agency as the familiar 
rise and fall of local temperature during the same period. It should 
* The time of mean minimum for September is by the observations 8" 31’ 
P. M. Cambridge M. T. From this time the western deviation increases till 
11" 36’ A. M., the time of maximum declination. 
