Researches on Solar Physies. 191 
to be rejected. ee 
No doubt, if we knew of a case of the production of low tem- 
perature, and had at the same time an independent proof of 
consider the third hypothesis, which supposes that the reduction 
1s produced by matter coming from a colder region. Now, in 
Most so nearest the equator; and this is precisely the motion of 
* Does not the observation by Lockyer of the facula “giving out” appear also 
to indicate that the lower vegodie of a spot are in reality froater than the surface, 
leaving the inferior luminosity to be accounted for by the downrush of a cold at- 
mosphere from above? 
