PRITCHETT — EPHEMERIS OF SATELLITES OF MARS, lS8l. 357 



From this it will be seen that Phobos, even on the most favor- 

 able date, will be only about 14" distant from the limb of the 

 planet. In 1877 this satellite was observed with the 12^^ equa- 

 torial of the Morrison Observatory when only 'j" distant. In the 

 present opposition the satellite will be much fainter, but on the 

 other hand the brightness of the planet will be considerably di- 

 minished. It seems possible, therefore, that this satellite may be 

 seen with glasses of moderate size. 



Washington University, Nov., 1881. 



