An ExtraSt 
of ^ Letter written hy Sigmr Cafllni Frofeffor of Aftronomf in 
Bononiaj t& Monfeur Petit at Paris, and Englijljcd out of 
the Journal Des Scavans? cenctrning f czer all S^Qts^ late- 
ly difcover d thre in the Fla^et Venus. 
TO give you fome Account of my prefent Studies, Illiall 
acquaint you, that having been a good while veryaffidu- 
ous andcarefuU in making Obfervations of Fe^us tokG, whe- 
ther that Planet did not turn about its Axis, by a motion like to 
that of ^Hfiter and Mars 5 I met at firft with many difficulties • 
but at laft confidering, that I fbould fucceed better in my Obfex« 
vations at a time, when Venus is at a good diftance from the 
Earthy than when (lie is near theretOjI attentively obferv'd^ whea 
flie was rifen fomewhat high above tht Horizon A^d /hined bright- 
efaWheiher I could not difcern in Her fomc part remarkable either 
by itsbrightnefs or obfcurity^ among the reft, efpeciall|? about 
the middle of her Diske, And this I did not in vaine * for, I dif- 
covef d at laft towards the middle of her Body a part clearer 
than the reft, by which one might judge of the Motion or the 
Reft of this Planet. 
The firfttimel fawit.was 14. 1666. h,5.45^p.m« 
and then this bright part was very near the Center, on the North- 
fide. And at the fame time I obferved Wc^-ward two ohfcurs 
fpots, fomewhat oblong. But I could not then fee that refplen- 
dent part long enough, to conclude any thing from thence 5 nor 
was I able to fee anything wellof thofepartstill^fr/'/iS. 16^75 
on which day, a quarter of an hour before Sun-rifing Ifawagain 
a bright part , fcituated near the Seltion^ and diftant from the 
Southern Horn a little more thaa ; of its Diameter. And 
near the Ba(lern Ring I faw a dark and fomewhat oblong 
fpot, which was nearer to the Northern than the Southern Horn, 
At the rifing of the Sun I perceived 5 that this hright part 
was then no more fo near the Southern Horn, but diftant from 
k I of its Diameter. This gave me great fatisfaiflion. But 
Ttt 2 I 
