1 7 o IN STARRY REALMS. 



ficent instrument is one of the very finest in the world ; 

 perhaps, indeed, its optical perfection is at this moment 

 hardly surpassed anywhere. Like the great Lick tele- 

 scope already referred to, it is a monument of the con- 

 summate optical skill of the Messrs. Alvan Clark, of 

 Cambridge Port, in Massachusetts. 



But though these were necessary conditions in Pro- 

 fessor Asaph Hall's work, yet it would be absurd to 

 attribute his success either to the locality of his workshop 

 or to the perfection of his tools. A man's genius is best 

 shown by the right use which he makes of his oppor- 

 tunities. Many faculties are required to make a skilful 

 observer, and those faculties require careful training and 

 long experience before they can be trusted to do valuable 

 and reliable astronomical work. The practical astronomer 

 is, indeed, an artist of a special kind. He must have 

 cultivated delicacy and quickness of perception, he must 

 have a nice manual dexterity, he must conduct his work 

 with much forethought and tact. It must be all care- 

 fully organized and planned. He must have anticipated 

 his difficulties, and decided how they shall be overcome 

 or evaded. Unless he possess these qualities, and many 

 more, he will not be a discoverer of the satellites of Mars, 

 no matter how superb the telescope he is provided with., 

 or how glorious the climate in which he is situated. 



It was in the middle of August, 1877, when the planet 

 was blazing in the glories of opposition, that Professor 

 Hall discovered the satellites. Tiny objects they indeed 

 were. Their feeble light was so faint that, to render 

 them visible at all, the fiery planet itself had to be moved 

 out of the field of view, or otherwise screened off. At 



