r 362 ] 
fmoaked glafs: immediately after which, looking 
thro’ the fmoaked glafs only, he perceived, that a 
fmall thread of light was ft ill vifible between the 
limbs, before, what he calls, the fecond contad: took 
place, which was not till four feconds after ; that the 
exterior contact appeared ftationary, or feemed to laft 
6 or 7 feconds ; that having obferved the total egrefs 
with the coloured glafs upon the fmoaked one, he 
brought Mercury upon the Sun’s limb again, by re- 
moving the colour’d glafs ; and that the fecond total 
egrefs did not happen till 6 or 7 feconds after the 
firft. When he obferved him at the diftance of about 
3 of his diameters from the Sun’s limb with both the 
glafles, he remarked, that the faid diftance feem’d di- 
minifhed, and Mercury’s diameter increafed. That 
the part of the Sun’s limb, where Mercury went off, 
to the extent of fix degrees of circumference, feemed 
under much the fame configuration, as the illuminate 
limb of the Moon about the quadrature, fomewhat un- 
even and undulating. The fame looked alfo redder 
than the reft of the dilk. This was about 18 or 20 
feconds before Mercury difappeared, and was feen 
thro’ the fmoaked glafs alone : for when the green 
glafs was applied, the appearance in a manner va- 
nifhed. 
The evening before the tranfit, he viewed the Sun 
with different-colour’d glaftes, varioufiy combined 
with one another, and with a fmoaked glafs ; and 
found, that a green glafs before the fmoaked one did 
beft : the Sun appearing of a filvery hue, like the 
Moon, and the fpots and the limb exceedingly well 
defined. 
M. de Barros, having thus deferibed the particular 
phenomena, attempts, and indeed very ingenioufiy, to 
account 
