on the Planet Mars. 235 
1777, April 17. 7h. 50’. There are two remarkable bright 
{pots on Mars. In fig. 1. tab. VI. they are marked 
aandb. The line AB exprefles the dire€tion of a 
parallel of declination. 10 feet reflector, g inches 
aperture, power 211 *. 
toh. 20’. They are both quite gone out of the difk. 
1779, ‘This year, in all my obfervations on Mars, there is no 
mention of any bright fpots, fo that I believe there 
were none remarkable enough to attract my atten- 
tion. However, as my view was particularly directed 
to the phenomena of this planet’s diurnal rotation, 
it is poflible I might overlook them. 
1781, March 13. 17h. 40’. 20 feet reflector. I faw a very 
lucid {pot on the fouthern limb of Mars of a confi- 
derable extent. See fig. 2. 
June 25. 11h. 36’. 7 feet reflector, power 227. Two 
luminous {pots appeared at @ and J, fig. 3.3 @ is 
larger than 4. ae : 
12h. 15’. With 460. a ee thicker than &, but & is 
rather pence 
¥2. i. 2 5 anis arawe inte nee: ae b eae thinner. 
June.27. ths 20’. Phe two lucid fpots are on Mars. 
Pune 25. Tins They. are both vifible ; a, fig. 4. is 
much thicker than 4. 3 
coh, 55. lines joining a and b hese not go through 
the center. 
June 30. toh. 48’. The {pot . ais vifible. fig. Ge 
11h. 35’. Both fpots are to be feen. 
* Phil, Tranf, vol. LXXI. Pe 127. and fig 176, 
liz oe gos 
