486 



OPPOSITION OF MARS, 1849-50, 



6) 3.678 rev. = 0.613 rev. = 15". 98. 

 One revolution of micrometer ~ 36". 05925. 



Mars compared with n. C 10669. The star became faint on the approach of the planet, and finally could not he distinguished. The several 

 powers were tried in succession without avail. The above observations were made after the star escaped from the rays, and by repetition, using the 

 " driving clock,'' as when measuring double stars. The measures are in declination between the star and the planet's cUr. The star still too faint 

 for good work. Power 161 employed. Planet's centre true south of star. 



