122 
COLONEL SABINE ON PERIODICAL LAWS DISCOVERABLE 
M. ScHWABE has not been able to derive from the indications of the thermometer 
or barometer any sensible connection between climatic conditions and the number 
of spots. The same remark would of course hold good in respect to the connection 
of climatic conditions with the magnetic inequalities, as their periodical variation in 
different years corresponds with that of the solar spots. But it is quite conceivable 
that affections of the gaseous envelope of the sun, or causes occasioning those affec- 
tions, may give rise to sensible magnetical effects at the surface of our planet, without 
producing sensible thermic effects. 
It may be confidently anticipated that so remarkable a coincidence in the degree 
of energy with which the causes producing obscurations in the luminous disc of the 
sun, and those producing the magnetic variations at the surface of our planet, appear 
to have acted in the different years between 1843 and 1848, will receive due atten- 
tion at those observatories which, by their more permanent character, are more 
particularly adapted for the investigation of problems requiring several years for 
their solution. 
As the physical agency by which the phenomena are produced is in both cases 
unknown to us, our only resource for distinguishing between accidental coincidence 
and causal connection seems to be perseverance in observation, until either the 
inferences from a possibly too limited induction are disproved, or until a more 
extensive induction has sufficed to establish the existence of a connection, although 
its precise nature may still be imperfectly understood. For such continued investi- 
gation we must look to those observatories which are permanent in their institution ; 
and in this particular problem, to those especially which combine astronomical and 
magnetical research. The hourly observations at the British Colonial Observatories, 
which, combined with M. Schwabe’s observations of the sun in Germany, have led 
to the discovery of the existence of the coincidence during the years 1843-1848, 
ceased in 1848, having accomplished the special objects for which they were insti- 
tuted. There are yet remaining for analysis, in reference to the disturbance-varia- 
tions, the hourly observations at Hobarton in 1841 and 1842, and the 2-hourly at 
Toronto in the same years, which will show whether the aggregate values of the dis- 
turbances were greater in those years than in 1843, as they should have been in con- 
formity with a periodical inequality having 1843 as a minimum epoch. 
Woolwich, March 16, 1852. 
