298 Janssen Solar Photograph and Optical Studies. : 
of the foliate form and subdivision, specially calling attention 
to them in the plate, where they are found in two squares sur- 
rounded by a heavy outline. It is necessary to insist on the fact 
that purely optical methods had informed us of the nature of 
the constituents of the surface with a minuteness which photo- 
graphy has not even now attained. It was also stated in the 
first of these articles that the estimated mean distances between 
the centers of these composite objects ranged from 2°57 to 1-42 
according to the degree of disintegration introduced by magnify- 
ing power, and the very important conclusion was reached that 
the light of the sun comes to us chiefly from an extremely small 
part of its surface—an indefinitely small part, but which is at 
any rate less than one-fifth of the whole. M. Janssen’s impression 
that the true form and relative area of these has first been shown 
by the Aner is a misapprehension, though arising most 
naturally in part from the vicious nomenclature of the subject. 
: na closer view we see t rse vague macula- 
tions or marblings* (formed as it seems to me by waves in the 
solar a ing regions of greater thickness and 
the plate is hardly possible, but as the individual “ grains” 
* This is seen in the Albertype on removing it five or six yards from the eye 
where details are lost. The ae ie igi 
Brace tho ove itctt) vagueness of the aggregations is in the original 
_t Indicated all over the Albertype lates, and shown in specific details in the 
two designated squares. —" 
