[ I0 7 ] 
The greateft femi-durations of the eclipfes of the 
fecond, third, and fourth fatellites in the nodes, are 
ih 27', i h 47', and 2h 24' *, refpe&ively. 
The nodes of the fecond Satellite feem to be at reft 
in about 50° of xs and si 5 hut the inclination of its 
orbit varies from 2 0 50' to 3 0 52': it was lead; in 
1 668, greateft in 1715, and feems to have been at 
its greateft and ieaft once in the intermediate years. I 
fuppofe it at the leaft in 1730. 
The nodes of the third fatellite in 1727, were in 
1 64° of sz and si, and move forward about 24° 
in 20 years: the inclination of its orbit in 1695 
was 3 0 , and has been increafing ever fince: it feems 
as if it would get to its maximum about 1 765, and 
would then be about 3 0 24'. 
The nodes of the fourth fatellite in 1730 were in 
134° of xs and Sly and move forward 2° in 12 years : 
the inclination of its orbit is about 2 0 40', and does 
not feem to vary above one or two minutes either 
way. 
From thefe elements, it will be eafy for any per- 
fon, moderately {killed in fuch matters, to conftrudt 
tables of the motions of the fatellites in the method 
of Mr. Pound, which may be feen in the latter part 
of Halley’s tables. 
I am, SIR, 
Your humble fervant, 
Richard Dunthorne. 
* The femi-durations of the eclipfes of the fourth fatellite will 
be about 2 / more at the afcending, and i' lefs at the defcending 
node, on account of the excentricity of its orbit, 
P a XXI. Dif- 
