208 
PROCEEDINGS OE SECTION A. 
II.— List of Works Consulted. 
(1.) Report on the Determination of Differences of Longitude in the West Indies 
and Central America. By Lieut. Commander F. M. Green, U.S.N. 
(2.) Smithsonian Contributions to Knowledge, No. 223, vol. 16. 
(3.) A.stronomische Nachrichten, No. 2636. 
(4.) United States Coast Survey Report, App. 18. 
(5. ) Royal Astronomical Society, vol. 51. 
(6.) Report on the Telegraphic Determination of Australian Longitudes, via 
Singapore, Banjoewangie, and Port Darwin. 
(7.) Annals of the Cape Observatory, vol. i., Part II. (Dr. Gill.) 
(8.) Account of Observations of the Transit of Venus of 1874. (Edited by Sir 
George Airy.) 
(9.) Dunecht Observatory Publications, vol. iii. (By the Earl of Crawford 
and Balcarres.) 
(10.) Royal Astronomical Society, vol. 38. (General T. Addison, C.B.) 
(11.) Account of the Operations of the Great Trigonometrical Survey of India, 
vol. ix. (General J. T. Walker, C.B., R.E., F.R.S., &c.) 
(12.) Report of the Great Trigonometrical Survey of India for 1876-77. 
(13. ) Telegraphic Determinations of the Difference of Longitude between Karachi, 
&c., and the Government Observatory, Madras. (By Norman Pogson, C.I.E., 
F.R. A.S., &c., Government. Astronomer.) 
(14.) Astronomishe Nachrichten, No. 2486. (Prof. F. A. C. Oudemans.) 
(15.) Telegraphic Determination of Longitudes in Japan, China, &c. (By Lieut. 
Commanders F. M. Green and C. H. Davis, and Lieut. J. A. Norris, U.S.N.) 
(16.) Royal Astronomical Society, vol. xlviii. (ByMr.elohnTebbutt, F.R. A.S., &c.) 
(17.) Report on the Determination of the Boundary Line of Colonies of South 
Australia and New South Wales. (By Charles Todd, F.R.A.S., Observer and 
Superintendent of Telegraphs, South Australia, 14th December, 1868.) 
2. — TRANSIT OF MERCURY, 1894, November 11. — Egress. 
By J. P. THOMSON, F.R.S.G.S., <tc. 
The instrument used to observe the 'Transit of Mercury was an 
equatorially-mounted refracting telescope, 6 feet focal length, with 
object glass G inches in diameter, built by Sir Howard Grubb in 18S4. 
It is the property of Mr. F. D. G. Stanley, F.K.LB.A. The telescope 
rests on a hollow cast-iron column, 5 feet 9 inches in height and 
18 inches diameter at the base, in which is placed the driving clock. 
The whole metal work is mounted on a. stone and concrete foundation 
carried down to the solid rock 6 feet below the surface of the ground, 
2 >erfect freedom from vibration being thereby secured. The observa- 
tory, which is situated at Ardeneraig, Toowong, the private residence 
of Mr. Stanley, is a wooden building 12 feet square, with roof arranged 
so as to roll entirety off on a railway and framing built to receive it. 
There can be no doubt whatever that in a line climate this arrange- 
ment possesses many advantages to which I shall refer later on. 
Included in the equipment of the observatory is a transit instrument 
by Carl Bamberg, of Berlin (1879). This is placed upon a stone 
pedestal. The observations are taken through the hollow central axis 
of the instrument, the eyepiece being fitted with micrometer. A 
magnifying power of 100 diameters was used in the equatorial for the 
actual observation of the transit, this having been found, after repeated 
tests, to give the most perfect definition. The object glass of the 
telescope was stopped down to 8 inches. 
The party consisted of His Excellency General Sir Henry Wylie 
Norman, Governor of Queensland, Messrs. F. D. G. Stanley and Arthur 
Cleminson (of the Surveyor- General’s staff), time recorders, and myself, 
who observed the transit. There were three chronometers used— 
namely, No. 542, mean time, by Frodsham, in charge of Ilis Excellency 
the Governor; No. 2189, also mean time, by Arnold, in the hands of 
