362
NOTE ON THE LUNAR THEORY.
[465
-iy 2 c
sin
c 4- 2g
- i Ÿe 2
33
2c — 2$r
-l|y 2 C 2
33
2c 4- 2p
+ Á7 4
33
4p.
y (Plana) =
y _
ye 2
— t 7 3
sin
9
4- ye —
t 76 s
33
c- g
4- ye —
f 7e 3
~ 17 3 e
33
c+ g
+ I ye 2
33
2c- g
+ | ye 2
33
2c 4- g
4-^ye 3
33
3c- g
+ 1 76 3
33
Sc+ g
_ 1
2 4 7
33
3g
+ h y 3 e
33
c —3 g
- ïï 7 3 c
33
c+3g.
To compare these with the elliptic values, it is necessary to write e (1 + £ y 2 ) in
place of e. Making this change, or say reducing Plana’s (e, y) to the elliptic (e, y),
I write down in a first column the transformed coefficients, and in a second column
the elliptic coefficients, as follows:
Plana, with Elliptic e, y
1
1
Elliptic
1
+ e - $ e 3
4- e 2 —| e 4
+ Ä e 3
+ t* 4
-f y 2 e 2
-f y 2 e
1
+ e — -|e 3
4- e 2 - £ e 4
+ I* 3
+ fe 4
0
0
cos c
33
33
2 G
3c
33
33
33
4c
2 g
c-2g.
Plana, with Elliptic e, 7
Elliptic
V —
2
Z
+
2
e -1 e 3
4-
2
e — ^e 3
sin
c
4-
5
4
e 2 ~ M e 4 — ^ 7 2 e 2
+
5
4
e 24 e
33
2c
4-
13
T2
e 3
4-
13
T2
e 3
33
3c
4-
103
W
e 4
4-
103
e 4
33
4c
-
i
7 2 - re r ß2 + s 7 4
-
l
4
y 2 4- y 2 e 2 4-1 y 4
33
2g
+
a
4
y' 2 e
-
1
2
y 2 e
33
c
-29
-
1
2
y 2 e
-
1
2
y 2 e
33
c
+ %
-
y 2 e 2
4-
3
16
y 2 e 2
33
2c
-%
-
13
TÏÏ
y 2 e 2
-
13
TÏÏ
y 2 e 2
33
2c 4- 2<7
4-
1
32
7 4
4-
1
32
7 4
33
4,7-