266 
Jottings in Solar Physics, 
[May, 
IV. JOTTINGS IN SOLAR PHYSICS. 
By A. H. Swinton. 
» STRONOMERS have long noticed that one half of the 
sun’s face is frequently very much more spotted over 
than the other half, so that as it rotates on its axis 
every twenty-five days and a fraction the spots turn towards 
and away from our globe, much as a revolving light blinks 
out its warnings to the mariner at sea. If, then, the sun- 
spots indicate progressive changes transpiring in the luminous 
disk of the sun, and revealed to us in the writing of the 
magnetograph, and if these changes are in any way con- 
nected with the amount of light and heat emitted by the 
disk of the sun, we should then certainly expeCt to find these 
sun-phases mirrored in the terrestrial phenomena which 
surround us. At the commencement of last spring I devoted 
considerable attention to watching the sun’s disk, and noted 
down carefully these minor times of spots and no spots, 
which with the telescopic power employed appeared to be 
of very unequal duration, although it is not at all improbable 
that they ran through their appointed cycles and periods. 
Thus when I began my diary at the end of January I ob- 
served no spots. One solitary spot came round on the left 
of the sun’s disk on February ist, and inaugurated a period 
of sun-spottiness that terminated on the 21st of the month. 
The sun’s disk then appeared clear until the 25th, when 
some spots came round again. They continued visible till 
about the 28th, when they were on the point of disappearing 
round the right side of the sun’s disk. Then ensued a 
period of no spots that lasted until March 8th, when the 
great army of spots was round again. They did not dis- 
appear until after April 24th, so that at this time it would 
seem that the entire superficies of the sun was spotted over. 
For a brief period, from April 29th until May 5th, I observed 
no spots. 
We then have apparent times of sun-spots, indicating 
hidden phases of the sun, that doubtless have their cycles 
and periods. In connection with the times of spots and no 
spots I noted down any sudden atmospheric changes and 
any record of earthquake shocks I met with ; and here, I 
think, I fairly detected a coincidence. Thus on February 
28th, when the spots were on the point of disappearing, 
