160 - TRANSIT OF MERCURY. 
distant from the planet one-third of Mercury’s diameter. All 
who express an opinion think the phenomena recorded are 
subjective. 
It is obvious therefore that with regard to the phenomena of 
Mercury in transit there is much yet to be decided, and every 
opportunity should be taken to clear up these uncertainties, On 
looking about me as to the means at my disposal for observing 
Mercury last month, I found that I could command six teleseo 
having respectively apertures of 114, 74, 43, 43, 44, and 33; and 
in order to secure observations in the event of cloudy weather I 
determined to divide the observers into three parties, and put 80 
others might fairly look for fine. The inland stations selected 
were, (1) a point on the western railway 66 miles from Sydney and 
3,400 feet above the sea, and (2) a spot near Bathurst with an 
elevation of about 2,400 feet. My object in selecting these elevated 
ions was of course to have the benefit of clearer air as well as 
the distance from Sydney. At Bathurst Mr. Conder, chief of the 
Trigonometrical Branch of the Survey Department, used the 
Schréder telescope kindly lent for the occasion by the area 
General ; and Mr. Brooks, trigonometrical surveyor, used a 9412 
which was at one time the transit instrument in the Observatory, 
but was equatorially mounted for the occasion. At Kaas 
Mr. Hargrave, who is double star observer at the Observatory, 
a 4¢inch Simm’s equatorial, and Mr. Bladen used a 41 Coo 
equatorial. In Sydney I used the 114-inch Schroeder refractor 
with polarizing eye-piece, and Mr. Lenehan used 
ecting 
ey e-pieces and two coloured shades which attended nO chang® 
Line, and the Superintendent of Telegraphs had cose 
observing stations with the Observa , L determines & 4 
local observations for time, and by sending cloc Pie accurate 
diately before and after the transit.to secure pe 
Sydney tim 
"iad Sor 4a pserving stations : 
nd for the hical position of the o gn 
matter whi eg wee of Venus involved considerable 
