599. ASTRONOMY, Variations of light.—
I think your conjecture that the periodical
variation of light in certain fixed stars proceeds
from maculæ, is more probable than that
of Maupertius, who supposes those bodies May
be flat, and more probable also than that which
supposes the star to have an orbit of revolution
so large as to vary sensibly its degree of light.
The latter is rendered more difficult of belief
from the shortness of the period of variation.—
To Professor J. Madison. Washington ed. ii, 247.
(P.
1787)