TRANSIT OF MERCURY. 165 
and able to estimate or measure the amplitude of the vibrations, 
so that we can tell how far they would affect the observations. 
am not at present prepared to say what is the best thing for the 
observer to do under these circumstances, but I hope to return to 
it after further experiments, 
TanvLar STATEMENT oF THE OBSERVED Times oF TRANSIT OF Mencury. 
1st External ist Internal 2nd Internal | 2nd External 
Contact. Contact. Contact. Contact. 
he he Se, Bom a hs th, 8 a he oe 
We vents 8 21 44°64 | 8 23 39°14 | 1 40 26°65 | 1 42 8°95 
Se 22 8-00 43°00 29°25 4°25 
eee 21 20°00 10°00 23°00 3°00 
ee 22 15°00 46°00 16°00 16°00 
latgrave ....2.5........ 22 066 41°38 10°40 0-09 
Brentano cs ay 34 42°84 44°34 23°64 
See 22 5:00 35°75 geaee ee pea bce 
> SEAS eres 22 3°60 36°45 26°48 8°59 
Means ............ § 21 57°53 | 8 23 36°82" 1 40 25:16 | 1 42 9-217 
Computed ......... (821 14, | 8 22 59 14028 14211 
* Without Wright, 40°65. 
Report on Transit or Mercury. ; 
Observed at Sydney, November 8th, 1881, by H. C. Russell, 
Government Astronomer. 
At Sy dney the morning was very fine and seemed to promise 
good definition for the transit, but the first glance through the 
conditions existed at Katoomba and Bathurst. At ingress I was 
unable to use the large refractor because the time-ball tower 
nted me from seeing the sun at the time of ingress; I there- 
fore used the 7Hinch Merz refractor in the north dome, time was 
taken by having Poole mean-time chronometer so close to the 
©yepiece that I could hear the ticks and see the dial directly I 
turned from the telescope. I was ready to obse: me : 
before the predicted time, and found the definition of the sun's 
limb very bad indeed, at Sh. 21m, 34-648, thought I saw first 
“entact, but had to wait ten seconds before I was sure; making 
