90 (TRANSIT OF VENUS). PROF. McLEOD: REPORT OF- 
Cobourg had no transit instrument and the time therefore depends entirely upon the 
exchange of signals by telegraph. Interpolating we get for this error, at the time contact 
was observed, chrometer fast on Toronto mean time 2" 28°67. 
May 13, 1883. 

Report of observations at Winnipeg by Prof. McLxon, M.E., McGill University, Montreal. 
[Communicated by A. Johnson, LL.D.) 
(Abstract.) 
The instruments placed under my care were a four inch refracting, alt-azimuth 
telescope ; a portable transit by Messrs. Troughton and Simms and two mean-time chro- 
nometers—664 Tobias and 652 Murray. The telescope is in the possession of McGill 
College ; it has a focal length of 62 inches and was provided with a first surface reflecting 
prism, an Airy eyepiece of power 160, and a neutral tint wedge. 
The eyepiece and prism were made specially for this observation by Mr. Gundlach of 
Rochester, New York, and the wedge, which was obtained from England, is similar to 
those used in the British observations. The telescope has a slow motion worm-gearing 
with handles for both altitude and azimuth. The mounting is very steady. The tripod 
Was unconnected with the floor of the building and rested directly onthe ground. A 
rough, adjustable seat was made at the station. The following will indicate the optical 
performance of the telescope. 
1. The disc of a bright star out of focus is round, but with a somewhat jagged edge. 
There is the usual change of colours as the eyepiece is pulled out, namely :—from greenish 
to a green centre bordered by green changing as it is pulled still farther out to a uniform 
light purple dise. 
2. On a night of not very good definition and full moonlight o Cassiopeiae was easily 
seen double. 
3. The “rice grains” on the sun on the day of the transit were just visible with the 
thin end of the wedge. The “rice grains” are generally easily visible. 
The transit instrument belongs to the observatory at Quebec. It has a clear apreture 
of 1? inches and a focal length of 24 inches. The pier was built from six feet below the 
surface of the ground. 
The chronometer 664 is the property of the McGill College observatory, it was 
repaired and cleaned by the Messrs. Bond at Boston, U.S., for use on this expedition. 
The chronometer 652 is the property of the British Admiralty, being lent for the pur- 
poses of the transit of Venus observations in Canada. 
We arrived at Winnipeg on Wednesday, November 22nd. The pier for the transit 
instrument had already been built and arrangements made—under the direction of 
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