982 REMARKS ON THE TEMPERATURE COEFFICIENTS, ETC. 
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Whence =33q.+9 
or the temperature coefficient g will be the arithmetic mean between 
g, and q,, the values derived from the experiments in which the 
North and South Poles respectively are presented. 
The probability that an alteration in the distribution of magnetism 
does sometimes accompany a change in the temperature of a magnet, 
was suggested by the results of temperature experiments made by 
me in March, 1861, on two magnets in use at the Toronto Observa- 
tory. With one of these—the magnet of our small bifilar—the re- 
sults were as follows : 
aT Ot+ Ge 
North pole presented ..................... J =0000608 ; 
South go Sitededastnaecer reece) (9 OUOLLO ais 
Giving) jcc cse 5: ‘diieceedacsoeee'enets. Qy'=0000854.; 
But the scale Sociicieut J aioveeceueedyice OOOMESE: 
WIEN CE ee ce se tse cee oscaslsnaoacs 7 =0°74 nearly. 
But from the observations in the period to which the foregoing 
value of & belongs, and by the method on pp. xxiii. and xxiv. of the 
Introduction to the third volume of the Zoronto Observations, the 
equivalent in scale divisions for a change of one degree of tempera- 
ture, was 0°66 nearly, a result with which the above value of 7 shews 
a very tolerable accordance. 
The value of g, = 0001105, which is given above, agrees very 
fairly with the results of a series of experiments in 1843 and another 
in 1845, which gave respectively g—0001032 and g—0001138. 
Again, in page xxvii. of the third volnme of the Toronto Observa- 
tions, we find that by experiments in 1843-44, on the magnet of 
Lloyd’s Vertical Force Magnetometer, 
g = 000112; 
and by experiments in 1846, 
y = 00007. , 
But in March, 1861, when the North Pole of this magnet was pre- 
sented, I found the partial value of the temperature coefficient to be 
J, = 000106 ; 
