MARS AS A WORLD. 167 



these extraordinary " canals." We naturally try to obtain 

 from terrestrial phenomena some clue to their explanation. 

 The late Mr. Proctor, to whom we are indebted for the 

 first successful attempt to construct a useful map of Mars, 

 regarded the canals as rivers ; but, as Mr. Maunder has 

 so well pointed out, the objections to this view are insu- 

 perable. In the first place, they often intersect each 

 other, a phenomenon which is almost an impossibility for 

 two rivers. The curious straightness of the canals is any- 

 thing but suggestive of the sinuosities of a river. We 

 also frequently find the canals running sheer across the 

 continents, connecting one sea with another. It is need- 

 less to say that the rivers on our globe do not display any 

 phenomena of this description. For the present, all we 

 can say is, that the " canals " present problems of a very 

 mysterious nature, which have not yet been solved. We 

 must anxiously await further really favourable oppositions 

 of the planet, in the hope that the quickened attention to 

 the subject, and the admirable optical powers now at the 

 disposal of astronomers, will permit of some satisfactory 

 results being arrived at. 



If we have reluctantly been compelled to leave the con- 

 figuration of Mars' surface in a somewhat ambiguous and 

 unsettled condition, it is satisfactory to turn to the very 

 clear and well-defined discovery of the satellites of the 

 planet. In this we have the pleasure of recording the 

 most interesting of pure telescopic discoveries that have 

 been made during this century. As our earth is attended 

 by one moon, as Jupiter is attended by four, Saturn by 

 eight, while the outer planets Uranus and Neptune are 

 also dignified by the companionship of satellites, it seems 



