on the Planet. Mars. 261 i 
from the. 20th of May till about the middle of September, 
when it feemed to be at a ftand. During this laft period the 
fouth pole had already been above eight months enjoying the 
benefit of fummer, and full continued to. receive the fun-beams ; 
though, towards the latter end,.in fuch an oblique direction as 
to be but little benefited by thems On the other hand, in 
the year 1781, the north polar {pot,, which had then been its - 
twelve-month in the fun-fhine, and was. but lately. returning | 
to darknefs,~ appeared {mall, though undoubtedly increafing 
in fize. . Its not being vifible in. the year 178: 3 18:00: objection 
to thefe: phenomena, being owing to the pofition of the axis, 
by which it was removed out of fight ;.moft probably, in the 
next oppofition.we fhall fee it renewed, and of confiderable ex- 
‘tent and brightnefs; as, by the pofition, of the axis of Mee 2 
the fun’s fouthern declination will:then be no more than 6° 257." 
on that planet. . 
Of the [pberoidical figure of Mars.:. 
_ That a planetary globe, fuch as Mars, turning ON an aXisy.. 
Bould be of a f{pheroidical form, will. eel find. admittance, . 
When two familiar inftances in Jupiter and the earth, as well 
as the known laws of gravitation and centrifugal force of ro- 
tatory bodies, lead the way to the reception-:of: {uch doctrines. 
So far from creating difficulties or doubts, it will rather appear - 
fingular, that the fpheroidical form of this planet,: which the - 
following obfervations will. eftablifh, has not already been no- - 
ticed by former aftronomers ;. and yet; reflecting on the general - 
appearances of Mars, we foon find that opportunities for making 
obfervations on, its. real form cannot be very. frequent: for, 
when it is near enough to view it to an advantage, we fee it 
6. generally 
