ATMOSPHERIC MAGNETISM. 
79 
proportion of paramagnetic force at different temperatures and different degrees of 
rarefaction, will require to be accurately ascertained, and this I hope to effect by a 
torsion balance, in course of construction (2783.). Indeed, I hope that this great sub- 
ject may be largely touched and tried by experiment as well as by observation, and 
therefore gladly make it part of these experimental researches. 
2968. One can scarcely think upon the subject of atmospheric magnetism without 
having another great question suggested to the mind (2442.), What is the final pur- 
pose in nature of this magnetic condition of the atmosphere, and its liability to annual 
and diurnal variations, and its entire loss by entering into combination either in com- 
bustion or respiration ? No doubt there is one or more, for nothing is superfluous 
there. We find no remainders or surplusage of action in physical forces. The smallest 
provision is as essential as the greatest. None are deficient, none can be spared. 
Royal Institution, 
September 14, 1850. 
APPENDIX. 
Received November 12, 1850. 
The following Tables of data obtained at Toronto, St. Petersburgh, Washington, 
Lake Athabasca and Fort Simpson, supplied to me by the kindness of Colonel 
Sabine, have not yet been published. The data for Hobarton and Greenwich are in 
the volumes of observations for those stations. 
