( 8 ^ ) 
feems allb liable to Inequalities that cannot well be ac- 
counted for, but from fome fuch Caufe as is before-men- 
tioned, the efied: of which will not eafily be reduced 
to any Rule, but from a long and exad Series of Ob^ 
lervations. And till fome better and more certain 
Rule can be found our, we may fuppofe, that the Ef- 
fed produced by this Caufe, is, during fmall Intervals, 
proportionable to the time. On this Suppofition I 
have compared fome Obfervations with others not 
made the fame Nights ,* and the refult is nearly the 
tame as in thofe which were obferved at the fame time 
' in both Places, as will appear by the following Parti- 
culars. 
The Immerfion of the Firft Satellite was obferved 
at Wanfied with Mr. Hadleys Refleding Telefcope on 
Auguji 4, N.S. 1715, about 45^' after the time of the 
Immerfion, as calculated from my Tables. By ano- 
ther Obfervation made 29, N. S. the true Im- 
merfion. preceded the Calculation from the fame Ta- 
bles I' 10". So that in Days the Satellite’s Mo- 
tion was accelerated as much as anfwer’d to 1' 55^^ in 
time. Suppofing therefore the Acceleration to have 
been in the fame proportion between July 28, and Au- 
guji N.S. then the true Immerfion July 28, N. S. 
would have happen’d at Wanjled zhoMt 15^' after the 
time by the Tables, which make the Immerfion at 
12 h. 48/ 47^^ App. Time. The true Immerfion there- 
fore was at Wanfled July 28, N.S. 12I1. 50^ d' App. 
Time; and at ’twas obferved at iih. 12^ xd' 
App. Time, the Difference being 37^ 34". 
Septemher 28, N.S. the Firft Satellite was feen emer- 
ging in the Refleder at ^aiijled 3 ' ^d' fooner than 
the Tables make the Emerfion ; and by the Mean of 
two more Obfervations made at the fame Place, and 
with the fame Telefcope, on the and i 6 th of 
OtloLer^lS,^. the true Emerfion preceded the Calcu- 
lation 
