2 58 Mr. Herscne’s Obfervations 
were taken; however, fince we do not mean to ufe thefe ob-_ 
fervations in our calculations, they may fuffice in a general _ 
way to thew, that the axis of Mars was actually about that 
time in fuch a fituation as our principles give it: for, reducing 
the two pofitions to the gth of May, that of the 11th, from 
an allowance of 26’ for the fituation of the planets, will be- 
come 62° 26’; and a mean of the two, 50° 13’ fouth pre-— 
ceding ; which, reduced to a heliocentric obfervation, gives. 
66° 30’, the north pole lying towards the left. Now, on cal- 
culating from the pofition of the node and inclination of the 
axis before determined, we find, that the heliocentric angle 
was 62° 49’, the north pole pointing towards the left; and a 
nearer agreement with thefe principles could hardly be expected 
from eftimations fo coarfe. If we go to the year 1777, and 
take the pofition of the two bright {pots obferved the 17th of 
April, we have 63° fouth preceding; this, reduced to a helio- 
centric quantity, gives 86° 26’ of inclination, the north pole 
being to the left. By calculating we find, that that pole was 
then actually 81° 27’ inclined to the ecliptic, and pointed ° 
towards the left as feen-from the fun. 
The inclination and fituation of the node of the axis of Mars 
with refpect to the ecliptic being found may thus be reduced. 
to that planet’s ownorbit. Let EC, fig. 30. (tab. X.) be a part 
of the ecliptic; OM part of the orbit of Mars; PEO a line 
drawn from P, the celeftial pole of Mars, through E, that 
point which has been determined to be the place of the node of 
the axis of Mars in the ecliptic, and continued to O where it in= 
terfects the orbit of Mars. Now, if according to Mr. pe La 
Lanpe we put the node of the orbit of Mars for 1783, im: 
1s.17° §8’, we have from the place of the node of the axis 
(that is, 11s. 17° 47’) to the place of the node of the orbit, - 
3 an 

