THE HAMILTON ASSOCIATION. 91 
few astronomers who have given attention to this subject was 
shown by diagrams in which I reproduced Prof. A. Wolfer’s 
(Zurich) curves of spottiness for each month for several years 
past, and drew under them the magnetic curves of H. F. given 
me by the Toronto Observatory. There seems to be a fairly 
regular “lag” in the curve of magnetic disturbances; 1. e., tha 
magnetic effect is often from two to three days behind the spot 
record. Pro. Wolfer and I have not yet arrived at a concord- 
ant view as to the cause of this lag—indeed, it is too novel a fea- 
ture to be yet definitely accounted for, but we are both working 
on the subject and may in a few vears arrive or help others to 
arrive at a conclusion. 
In my address I touched on the discovery that the Sun’s ro- 
tating rate is not the same in all latitudes, but that spots near 
the equator move around more rapidly than those at a distance 
from it. [I showed maps of the spot zone, with all the spots of 
several years marked upon it. The whole of the zone was 
shown to have been ina state of violent agitation, but that there 
were regions of special activity seemed clear. Spots breaking 
out in such regions would repeat again and again, for six or 
seven rotations, often with an interval of one or more rotations 
between each outbreak. And one drift appeared to be towards 
the equator, especially when the Sun-spot period was progress- 
ing towards a minimum. It seemed likely that in the imme- 
diate neighborhood of the equator, but not always coinciding 
with it, there was a strong current which prevented spots from 
bein frequent there. Very few spots, indeed, were placed 
just on the equator. 
The prominences were shown to be distributetd in belts, some- 
what resembling those of Jupiter and Saturn, and these belts 
moved in the reverse way to the region of spot pregnancy, 
which approached the equator towards minimum, whereas the 
prominences receded from it at that time. 
Such composite charts of the solar features have not before 
been made, and they are curiously interesting. They suggest 
convincingly that the Sun’s atmosphere is very tanuous, that 
there is no solid beneath it, but that the whole great Sun is a 
