25 Fe Henscmet' s Ofrvations 
aR? BPE Ey 





Firt | Second] ce ae 
Angles oy 
Angle Qe correction. {correct, 
Time of obfervation. 
Time o t Hea 




veer —SSe. 
A hoe) Dah | DM DM 
74 32 = LO = are tneae —-O 0 75 
47418 8) 20) SR lee 14h eae 



ee 



D. H. M 
June25 #1 36 
Ply tg) 40%) 12 

Iam to remark, that we have here admitted both meafures’ 
as equally good; and that, therefore, the refult is a mean of 
them both, and fhews the axis of Mars, June 25, 178%, to 
have been 75° 11’ fouth preceding. 
Our next bufinefs will be to reduce thefe two geocentric ob= 
Yervations to a heliocentric meafure. ‘This is to be done, as we 
have fhewn before, by a calculation of the angle Q, fig. 29. 
The refult of it fhews, that 10° 14’ are to be fubtraéted from 
the mean corrected angle of pofition, reduced to June 25, 1781, 
and 23° 18’ to be added to the angle which is the corrected 
mean of 13 meafures, reduced to O&. 4, 1783. Hence we 
learn, that on thofe days and hours, when the heliocentric 
places of Mars were gs. 24° 35’, and os. 7° 15’ (which would 
happen about July 18, 1781, and Sept. 29, 1783) an ob- 
ferver placed in the fun would have feen, on the former, 
the axis of Mars inclined to the ecliptic 64° 57’, the north 
pole being towards the left; and on the latter, he would’ 
have feen the fame axis inclined to the ecliptic 78° 59’, the 
north pole being then towards the right. 
The firft conclufion we may draw from ‘thefe principles is, 
that the north pole of Mars muft be direéted towards fome 
point of the heavens between gs. 24° 35 and os. 9° ey be= 
eaufe the change of the fituation ef the pole from left to right, 
which 

