471

Thus, by the observations ot W altherus,

J at oO e**' 57*'

^6- Longitude of the apogee ..

In 1749, (by Lacaille). 3 8 39

• > . . n 4 41 3

• • progressive motion in 253 years.

diff ^ ^* e mean annual progression * results equal to l' 6 ":m however, from the result of better observations and

e,l,od » by more than l' a".

Th

ofth ,n the Berlin Memoirs of 1785, M.Delambre, in treating\V i , ' °* ar Orbit, compares the places of the apogee given bya *id p? rUS Lacaille’s Calculations) Cocheon King, La Hire,^'amstead, with Maskelyne’s.

Astronomer. Year. Longitude of Apogee.

W a!therus .... 1496 .... 3 s 3° 57' 57" . • .Cocheon King. . 1279 .... 3 0 8 0 ...

La Hire . 1684 .... 3 7 28

Fl,

atnstead .... 1690 . , . . 3 7 35

0

0

Progression.65".38564.60662.11661.584

4) 253 .691

^lean

result. 63.423

He

th e ^ ec l u i ll octial year be estimated at 365 d 5 h 49“ 6*.374,•tonialistic year, since the time of describing 6S".423

V = 5^7^ X 24^) = 25“ 42 s .4, is 365 d 6 h T 24“.307.

Ti

g r eS(j i on m ° re accurate method, however, of determining the pro-§ft r Ihe apogee rests upon a very simple principle. Let4ft ® a r 'ght line, and draw TEt making with the axis majorttir 0u °h e ^‘P se > an angle TEA = SEA: now, the time& 1 Et S is less’than the time through the remaining arc

* Pr ■

ton *equ °g ress * on * 8 here meant to be used technically: a motion inla > or, according to the order of the signs.

3 p