38. M. Mitchell— Observations on Jupiter and its Satellites. 
° Ate "380, f= *20926. 
For this case Fri equation (1) 
1 
— 99 X’—— —_ — 000 0339, 
x < 295000° ‘niet 
and from the electrification 
X—-°99 X’=— -— =="00000355. 
sais00. 
The error amounts to 38, 10 and 4 per cent respectively in the 
three series. Had we taken Weber's value of v the agreement 
would have been still nearer. Considering the difficulty of 
the experiment and the many sources of error, we may con- 
sider the agreement very satisfactory. The force measured is, 
we observe, about 50000: of the horizontal force of the earth’s 
magnetis 
The difenenes of readings with + and — motion is due to 
the magnetism of rotation of the brass axis. This action is 
eliminated from the resu 
meters per r second satisfies the first and last series of the experi- 
ments the best. 
Berlin, February 15th, 1876. 
Art. V.—Notes of Observations on Jupiter and its Satellites ; by 
| Maria MITCHELL. 
THE following observations were made at the observatory of 
Vassar College; longitude 45 55™ 38s, latitude 41° 41’ 18”. 
The instrument used was the Equatorial telescope; the power 
usually 230. 
1874, May 2.—Observations on Jupiter began at 10% 18™. 
The seeing was excellent. With a power of 600 the ruddiness 
of the equatorial belt was brought out; two Janae dark spots 
on its upper portion were —— striking in appearance, the 
ted space between them being conspicuously white. 
The shadow of the 4th satellite was near egress. It touched 
the limit of the planet, in internal contact at 105 37™ 10s3, 
ore was last seen at 11" 2m 4588. At times during the hour I 
ht the shadow was followed by a companion s 
at rh May 3.—The 3d satellite of Jupiter was occulted a 
95 11m 98-5. [This observation is by Miss Fisher iealents 
with a small telescope.] 
556 ee 
