388 Obfervations on the Satellites of the Georgium Planet, 
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able as to enable me to examine them par ticularly for any: 
~ time without intermiffi ion. 
VI. At 7h. 34m. February 27th, when we the _ 
employed i in obferving with the thirteen feet refle€tor, M. 
Harding affured me that he faw, with perfee certainty, a 
~~ 
very ant luminous point at z, where I ‘had feen it alfo a 
little before, but not with fo much certainty. According to 
his delineation, it {tood‘in the orbit of the fixth f{atellite ; 
and it was found afterwards by comparifon that this lumi» 
_ mous point was actually that fatellite: for, from 1 th. 34m. 
on the evening Feb. 2rft, till 7h. 34m. on the evening of 
the 27th, five days 20 hours had clapfed, which divided by 
the period ofits revolution gives 4°25 revolutions; fo that the 
fatellite muft have ftood in z, about + of its orbit farther 
from d towards the weft, where it it aétually was potleant? 8 to 
accurate obfervation. 
Thefe fix obfervations, made in the courfe of ten days, 
during which the fatellite was always feen in thofe pomts in 
which, according to Dr. Herfchel’s determimation, it ought 
to be found, clearly fhew not only that we diftineuifhed the 
Yeti feletlité with the thirteen feet refiector, bat that the 
period affigned by Herfchel has been determined with great 
accuracy. Two obfervations, however, made later agli 
“to me to be worthy of notice. 
VIf. On the evening of the 6th of March, when Saturn 
was diftant only from 11 to 1£ degree from the illumiated 
half of the moon, I aiicay ered the four outer fatellites with 
the' thirteen feet reflector and a maenifying power of 238. 
On. account of fome meafurement which I had long wifhed 
to make under fuch circumftances, I applied to the reflector 
a magnifying power of 532 ; and it is certain that with this 
“power, almoft ‘double to the former, at fo {mall a -diftance 
from the ‘moon, I faw much better, though the light was _ 
confiderably weakened; for, at the firft view, I not only 
clearly difcovered the firft: fatellite in its weftern digreflion 
6 and 
