436 Scientific Intelligence. 
1853, discussed the results of measurements made with the helio- 
meter, and arrived at substantially the same result. Although the late 
Mr. Arago referred to some of the author’s views regarding terrestrial 
one of the poles of Mars, a great mass of brilliant matter, analogous to 
a mass of terrestrial snow. This very substance is even supposed, with 
great probability, to seriously interfere wi accuracy of telescopic 
observations, owing to the optical disturbances arising from the irradia- 
tion of such an extremely bright object. It is also manifest that if this 
its dimensions to vary, and thus the power of the disturbing influence. 
circumstances show that great caution should be used in accepting 
a ago, when controverting and disproving an erroneous theory of the 
Earth’s figure, put forward by Playfair, and which has since acquired 
rial ocean. I have assign ; 
osing the ocean to have its present volume. It also a 
s that if the Earth had a very great ellipticity, such, for examp' 
so frequently assumed for Mars, the reverse would take place, and : 
