On the Scheme of a Perpetual Full Moon. 15 
page pits we have 1+) +(1+ 39) v= 
wty 
Sei! ue ea 
+ S14 — 2(1 +d) ot 
Cae) vy wkd eto): ; 
ro x 37°+3(1+ )jv?—&e. or v= 2 very nearly. In 
the first example, v = ‘00000144, nd in the second, v= 
-00004457. 
To apply this in the case of the real moon, we have y= ——~" 
390 ? 
the angular distance of the sun and moon being x. Hence, 
x COS,7% 
j 
Fy dy let she SIE 
1+ pl? 1 
Goole 
the common centre of gravity of the earth and moon is about 
nine miles further from the sun in syzygies than in quadratures. 
The mean value of v for an entire lunation is found by multiply- 
— =*0000000932 cos.?x; so that 
) Bcos.2z 
300 x 1+ nie 
the sum of all the v’s is =z-+sin. z cas. z X 
ing it by z, when it becomes 5 the fluent of this or 
Pi lhe 
2(59011 + D) 
this, when z=360°, becomes 360° x TCCUES EST 2 which di- 
vided by 360° gives 0000000466 for the mean increase of the 
radius vector. 
It would hence appear, that the earth’s orbit (if the time be 
given) is increased in consequence of its connexion with the 
moon ; and that the radius vector of the sun, along with that 
of the centre of gravity, is lengthened by unity in the 7th decimal 
place at syzygies. Although the earth and moon are in motion 
about their common centre of gravity, this cannot protect it from 
these little inequalities; for gravitation is regardless of motion, 
and the centrifugal force the same as if the earth and moon were 
concentrated in their common centre of gravity. 
If you think this speculation deserving a place in your excel- 
lent Miscellany, the insertion of it will much oblige, 
Sir, 
Your very humble servant, 
Henry MEIKLE. 
Ppp? and 
IV. A 
