APPENDIX F CIX 
Dec. 7, 3 p.m.—The Solar Rotation (illustrated) by J. S. Plaskett, 
B.A. 
Dec. 21, 8 p.m.—Annual Meeting. 
SPRING Term, 1912. 
Meteorological Phenomena, (illustrated) by Otto 
Klotz, LL.D. 
Feb. 8, 8 p.m.—The Making of a Great Telescope, by J. A. Brashear 
me. D: 
Feb. 15, 3 p.m.—(1) Notes from the Washington Meeting of the 
APCE US As by Wo Fo King °C MEG: and Js: 
Plaskett, B.A. 
(2) Some Surveying Experiences, by J. J. 
McArthur, D.LS., Wm., Ogilvie, D.L.S., and 
J Crate DAS: 
Feb. 29, 8 p.m.—The Moon (illustrated), by Otto Klotz, LL.D. 
Mar. 14, 3. pm.—Precise Levelling in Canada, by F. B. Reid, D.L.S. 
Mar. 28, 8 p.m.—The Heavens Through a Field Glass (illustrated) 
bya Parker MA 
3 p.m.—Review of Current Progress in Astronomy, by 
Members of the Observatory Staff. 
.—The Planet Jupiter (illustrated), by Sir Joseph 
Pope, K.C.M.G. 
May 9, 3 p.m.—The Solar Rotation, by R. E. DeLury, Ph. D. 

Jane IS 3. p.m: 
April 4 
? 
April 25, 
co 
io) 
5 
The following is a brief abstract of each of the technical papers 
presented. 
1.—“‘ Methods of the Allegheny Observatory,” by R. J. McDiarmid, 
M.Se., dealt chiefly with the instruments and methods used in 
spectroscopic work at this observatory. 
2.—“ More Crumbs from Europe,” by Otto Klotz, LL.D., F.R.A.S., 
was a sequel to his Lecture of two years ago, entitled “Scientific 
Crumbs from Europe,” and gave in the same delightful way matters 
of great scientific value gathered on a recent trip. . 
3.—-“The Solar Rotation,” by J. 8. Plaskett, B.A., was a description of 
the instrumental equipment employed, the methods of observation 
followed and the precautions necessary to obtain accurate values 
in determing the solar rotation by the Doppler displacement of the 
spectral lines at opposite limbs of the sun. The results of the 
measures of a large number of rotation plates were also given and 
some interesting conclusions derived from these measures were 
discussed. 
