58 Mr. R. H. M, Bosanquet on 
The temporary effects of changes of temperature on per- 
manent magnets are also well known to be such as would 
certainly vitiate any accurate measurements founded on such 
magnets, in the absence of special precautions. 
‘he following Table contains the mean results of sets of 
observations made at different times during the present year. 
The first two entries contain the observations made use of in 
the paper above referred to, but divided into two groups and 
corrected for an improved value of the moments of inertia of 
the magnets. 
Mean date. SERIES M. Ee Place. 
sets. 
February 18 ... 9 12039 "18044 | Nonmagnetic room. 
Waren asses ac 6 11822 "18075 53 x 
i; Sal dane ee 12 11767 17261 | Laboratory. 
SANOPIL GS eeaaun ccs 11 11620 "17224 = 
September 18... 16 11119 "18020 | Nonmagnetic room. 
- a 14 11121 "17370 | Laboratory. 
2,000 
Ne 
ES 
11,000 5 
0 0 0 0 0 0 0 0 0 
February. March, April. May. June, July. August. Sept. Oct. 
