PROCEEDINGS OF THE SECTIONS. 
Section A. 
ASTRONOMY, MATHEMATICS, AND PHYSICS. 
—_—_—_—. 
1.—THE ANNUAL MARCH OF TEMPERATURE AT 
MELBOURNE. 
By R. T. A. Barnarp, M.A. 
(Printed in “ Philosophical Magazine,” October, 1900.) 
2.—THE LUNAR ECLIPSE OF JUNE, 1899. 
By A. B. Biaas. 
3.—ON THE PRODUCTION OF MICROMETRIC AND 
DIFFRACTION RULINGS. 
By Henry J. Grayson. 
[ Abstract. | 
Axsout six years ago I had occasion to use some finely-ruled 
glass plates, not exceeding the .01 in. in thickness, the lines 
upon them ranging from .02 in. to .004 in. apart. These, I 
found, were not readily obtainable commercially, so that I had 
to devise some method of producing them for myself. After 
a few experiments, I soon found I had no difficulty in ruling 
lines greatly exceeding in fineness and accuracy any of the 
kind I had hitherto seen, and as the matter was interesting to 
me, from a microscopical standpoint, I pursued it apart from 
my immediate requirements. 
