THE DOMINION ASTRONOMICAL OBSERVATORY 
The work of the observatory may be described under the following 
heads :-— 
Astronomy. 
Astrophysics. 
Time Service. 
Geophysics. 
Miscellaneous. 
With the observatory are associated certain surveys, namely the 
Trigonometrical Survey, and the International Boundary Surveys. 
The principal work done under the different heads is as follows: 
1. Astronomy, 
The present equipment in this department consists of three portable 
transit instruments with chronometers, chronographs, etc., which have 
been used for the determination of time at the observatory, and for 
determination of geographic positions of distant points. 
Tt is proposed to add « meridian circie of six inches aperture and 
? feet focal length, with a circle 36 inches in diameter. ‘This is in 
course of construction at the works of Messrs. Troughton & Simms, and 
it is hoped will be installed in a few months. 
A wing to the present building has been constructed to accommodate 
this instrument as well as two of the portable transits above referred té: 
This wing is built of stone, like the main building, but has an inner wall 
and roof of sheet iron. Free circulation of the outer air between the 
two walls is secured by louvre openings in the outer wall. In the design, 
provision is made for two four-inch telescopes as collimators for the 
meridian circle. Collimators are also provided for one of the transit 
instruments which are to be housed in the same wing. 
The portable transit instruments spoken of were made by Messrs. 
Cooke & Sons. They are of about three inches aperture and thirty-four 
inches focal length. The telescopes rest upon solid iron stands, with 
reversing apparatus. Two of them are provided with registering or 
“ Repsold ” micrometers, for automatic record of transits. The third 
is now being fitted with a micrometer in the observatory workshop. 
These micrometers may be revolved ninety degrees, and used for 
measuring zenith distances. 
Latitude levels are attached so that the instruments may be used 
as zenith telescopes. Thus one instrument serves for the determination 
of the two co-ordinates of a place. 
