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POPULAR SCIENCE REVIEW. 
disappointing to find tliat no provision was made for photographic and 
heliometric work at Cape Town, which was absolutely the best southern 
station of all for mid-transit observation. 
Observations by Lord Lindsay's Party at Mauritius. — Lord Lindsay’s 
preparations were so complete, that a special interest attaches to the ob- 
servations made by his party. We quote nearly in full his account, in a 
letter addressed to the Astronomer Boyal : — 
“ The morning of the 9th was cloudy before sunrise and for a short time 
after. The first external and first internal contacts were missed from this 
cause. We did not see the Sun until 1 h. 2 m. after the first external con- 
tact, when it came out for a few minutes, when photographs and measures 
were obtained. It was not till 8 a.m. (local mean time) that it became 
fairly fine, and remained so, with small periods of cloud obscuration, until 
the end of the transit. 
(( Photography. — I took 271 plates, out of which number perhaps one 
hundred (100) will he of value ; cloud and the very high temperature of 
the camera were much against me. Temperature varying from 96° to 116°. 
11 Heliometer. — Mr. Gill obtained five (5) complete determinations of 
greatest and least distances of the centres of the Sun and Venus, besides 
nine measures of cusps and two separate determinations of the diameter of 
Venus near the end of the transit. 
“ 6-in. Equatorial. — Dr. Copeland obtained with this equatorial and the 
Airy double image micrometer, fifteen (15) measures of least distance of 
Venus from the Sun’s limb, and ten (10) measures of cusps. Dr. Copeland 
also observed the last internal and external contacts with this instrument. 
“The images of Venus, one brought into contact with the other, and then 
slowly rotated by the position-circle, showed no symptom of oblateness 
(ellipticity). Dr. Copeland observed the second internal contact with full 
aperture and first surface reflecting plate. The second external contact was 
observed with the double-image micrometer; the images superposed on 
account of faintness of the images. 
“ 4-m. Equatorial. — The last internal contact was observed with this in- 
strument and the Merz polarising eye-piece by Mr. Gill. He also observed 
the last external contact with the heliometer. 
11 Both Dr. Copeland and Mr. Gill agree that the contacts of Venus and 
the Sun are remarkably similar to those seen on the model. They also 
agree that any phenomena which could be classed under the head ‘ Black 
Drop ’ took place and disappeared within a period of five (5) seconds. 
u Time. — Transit Lnstrument. — Very accurate determinations of the time 
were obtained on the six nights previous ; and one star and azimuth-mark 
on the night following, by Dr. Copeland with the 4-in. reversing transit. 
All the photographic exposures are automatically registered on the chrono- 
graph by a method which gives the actual duration of the exposure. The 
heliometer observations were also registered thus: Dr. Copeland observed 
eye and ear — all other observations (photograhic and heliometric) were 
also observed eye and ear as a check on the chronograph. During the 
actual work of the transit I had eight assistants, not counting myself or 
Mr. Davis. Mr. Gill had six, including the Hon. M. Connal, Surveyor- 
