[ 156 ] 
The obfervations here referred to, made by Capt. 
Holland and others of his party, are to be found in 
Philofophical Tran factions, Vol. LVIII. for the year 
1768, and Vol. LIX. for 1769, and other papers. 
Tent to me from Capt. Holland, which I have' the 
honour of prefenting to the Royal Society, together 
with this paper. 
I have re-computed the times of Enfign sproulB’s 
©bfervations made at gasped bay, applying the equa- 
tion of correfponding altitudes, which he had neg- 
lected ; and have annexed them, to his account of 
his obfervations, tranfmitted to me by Capt. Hol- 
land. 
It appears, that the obfervations of Capt. Hol- 
land, and his .party, were fometimes made with a 
two feet refleCtor of short’s confhuCtion, and 
fometimes with : an achromatic telefcope of dollond 
of io, and at other times, one of 12 feet. The 
obfervations at the royal observatory were alfo 
made with different telefcopes, at different times ; 
fometimes with a two feet refleCtor of short’s con- 
fhuCfion ; fometimes with a treble object glafs ;te- 
lefcope of dollond, of 31 feet; but oftener 
with a 6 feet refleCtor,. of short’s confhuCtion. 
Thefe circumflances are always noted againfl the 
obfervations: I have only made ufe of the obferva- 
tions of the fir ft fateliite, as being much moret-exaCt 
than thofe of the others. 
1 reckon, that the 6-feet refleCtor fhews an immer- 
iion of the fir ft fotellite of Jupiter later, and an emer- 
fion fooner, by 20 // , than a 2-feet refleCtor ; or by 
13", than a 3 f- feet treble objeCt glafs refraCtor, or 
a 10 or 12-feet double objeCt glafs refraCtor of dol- 
. , L ON Do. 
