Physical Features of Saturn and Mars. 205 



The planet was frequently examined, whenever the atmo- 

 sphere was in a favourable condition, until April 1854, the 

 time of the writer's departure from India, without any change 

 being perceptible, except that the peculiar features above de- 

 scribed had become gradually rather more conspicuous, so as 

 to be discerned with lower powers. This would arise partly 

 from the rings appearing at a greater inclination, or more 

 open, and partly, perhaps, from the eye becoming, through 

 practice, more familiar with the details. After the first scru- 

 tiny, in August 1852, no difficulty was ever experienced in 

 making out any of the peculiar points above described, pro- 

 vided that the atmosphere was sufficiently tranquil to admit of 

 using a magnifying power of 180 or upwards. The powers 

 usually employed were 277 and 365. 



Mars. 

 The views of Mars (Plate III.) were taken with the same in- 

 strument. The lower view, though the later in point of time, yet 

 precedes the upper, as regards the longitude or angular motion 

 of the planet, because its period of revolution is rather longer 

 than that of the earth ; the difference in longitude between the 

 two is about 90°. The other faces do not present such strik- 

 ing features, but are nearly blank. Former engravings of the 

 planet do not show any such distinct markings ; at least the 

 writer has not been fortunate enough to meet with any that 

 could be recognized as likenesses. Mars will not again be in 

 a favourable position for observation until 1856 ; in 1858 he 

 will be nearer still ; and it is to be hoped that on these occa- 

 sions still better drawings of him will be obtained. 



W. S. Jacob. 



21st Nov. 1854. 



NEW SERIES. — VOL. I. NO. II.— APRIL 1855. 



