C. E. Burtroy.—Physical Observations of Mars. 161 
No. 21. Longitude=220°. 1879, Nov. 11. 11° 40™ to 12" 0™, G.M.T. Definition 
was at times very beautiful with the magnifying powers of 120, 220 (achromatic) 
and 270 on the 8 inch reflector, the planet appearing with a perfectly hard and 
clean outline, quite free from all trace of stray light. Nevertheless, I found it 
impossible to draw so as to satisfy myself, especially with regard to the exact form 
of Burchardt Land and of Gruithuisen Bay, on account of the continually recurring 
tremors, partly due to the furious wind prevailing at the time. 
The faint streaks represented in Mr. Green’s map as running southwards to 
Oudemann Sea and Delambre Sea respectively, were at times well seen, though 
they are badly drawn. The streak connecting Huggins Bay with Oudemann Sea 
appeared like a narrow greenish ribbon with sharply defined edges, and is rudely 
represented in outline in the annexed diagram, copied from one made in my journal 
at the time. 
(a.) Huggins Bay. (b.) Huggins Inlet. (c.) Oudemann Sea. 
Diagram showing the form of the streak above mentioned, which is identical with Huggins Inlet (Proctor). 
Oudemann Sea was instantly recognised by its form, though its name was not 
known until the map was consulted after the night’s work was finished. 
No. 22. Longitude=233°. 1879, Nov. 10. 11" 55™ to 12% 20™ G.MLT. This 
drawing is remarkable for the apparent isolation of the W. end of Hooke Sea from 
the remainder of that marking by a patch of much lighter shade, visible on this 
night only, and consequently of a fugitive nature, probably akin to terrestrial 
clouds. A great number of minute details* were seen, which it was impossible for 
me to draw, as they were visible only by most transient glimpses. A faint streak 
connects Flammarion Sea (Green), with the dark arctic band. The northern portion 
of Flammarion Sea to the east of Huggins Bay was dark gray, the other shadings 
appearing greenish gray. No mention is made in the original notes of any trace 
of the streaks from Trouvelot Bay or Huggins Bay, which last was judged to be 
on the polar diameter of the disk at 11°56", G.M.T. It was not possible to decide 
whether any southern snow could be seen or not. The northern snow was of large 
dimensions, but it was very difficult to make out its true form. 
The instrument used was the 8 inch reflector, with an achromatic eyepiece mag- 
nifying 220 diameters. 
* Consisting chiefly of variations in the tone of the shadings, and irregularities of their outlines 
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