232 Original Articles. [April, 



very little different from what it is on our Northern hemisphere, 

 extending according to local peculiarities, such as those presented by 

 the elevated table-land of Northern Asia in this case so low as from 

 40° to 60°, while on Mars the farthest limit yet known to be reached 

 is 50° ; the mean summer temperature of which, supposing the pres- 

 sure to be the same as on the Earth, cannot therefore be less than 

 32° Fahr., and in many parts must be very much above it. Fifty is 

 nearly the latitude of London ; the mean annual temperature of which 

 is 46 0- 9 Fahr. ; but supposing the Earth were moving in the orbit of 

 Mars, with only her present atmosphere, this temperature would be 

 reduced in consequence of diminished solar influence to 2 o- 03 Fahr. 

 Obviously, then, there must be some great modifying causes at work to 

 counteract the effect of the planet's increased distance from the sun. 

 What these most probably are, we shall consider when we come to an 

 examination of Jupiter. For the present, we will only remind the 

 reader of Professor Tyndall's experiments, showing that the effect of 

 the distribution of aqueous vapours through an atmosphere is to 

 prevent the dissipation of thermic rays into space, and to envelop the 

 surface around which it lies in a warm mantle. Besides the evidence 

 afforded of a Martial atmosphere by the phenomena described, inde- 

 pendent proofs have been obtained by spectroscopic examination, so 

 many strong lines being seen in the extreme end of the red, and such 

 well-marked bands at the opposite part of the spectrum, as to render it 

 certain that the atmosphere is of considerable depth. 



The other superficial features of the planet are so striking, that 

 drawings made by Mr. De la Rue, and the late Captain Jacob, of 

 Madras, were referred to a Committee of the Royal Astronomical 

 Society, with the view of mapping it out. Two of these, by the former 

 gentleman, form a part of our illustration, and are peculiarly interest- 

 ing, inasmuch as they exhibit Mars under the two different aspects, 

 consequent on the axial rotation during an interval of two hours. In 

 India, where atmospheric conditions are very favourable for obser- 

 vation, his aspect is exceedingly beautiful, and begets the inevitable 

 conviction of his being, as described by Mr. Grant, " a perfect little 

 world, with continents and seas like ours." In the drawings of Cap- 

 tain Jacob, representations are given of what appeared to him a chain 

 of lakes near the South pole, similar to, though larger than, those of 

 North America ; and to all observers there is a marked difference of 

 hue on different parts of the surface — some (the land) appearing red, 

 while others (the seas) look greenish. There is also indication in the 

 occurrence of temporary fogginess of detail of considerable atmospheric 

 vicissitudes. 



On considering the physical constitution of Mars, can we conceive 

 of anything in it incompatible with life ? On the contrary, does not 

 the presence of the precise conditions, which we know to be adapted 

 to its maintenance, afford us the best evidence for believing in its 

 manifestation ? 



The position of Venus with respect to the sun is such, that even 

 in the improbable absence of a system of compensation of the opposite 

 tendency to the one which operates on Mars, there would be nothing 

 in it to render her uninhabitable, the mean quantity of light and heat 



