An ActraSt 
of a Letter mitten by Signor Caffini Pr&feffor of Aflrommj in 
Bononia, to Monfieur Petit at Paris, and Englifhed out of 
the Journal DesScavansi concerning fever all Spots, late-* 
ly difc over 'd there in the Planet Vq nus. 
T O give you- feme Account of my prefent Studies, I (hall 
acquaint you, that having been a good while very ardu- 
ous andcarefull in making Obfervations of Venrn^ to fee, whe- 
ther that Planet did riot .turn about its Axis, by a motion like to 
that of fnfiter and Mars $ I met at firft with many difficulties 5 
but at laft confidering, that I fhould fucceed better in my Obfer- 
vations at -a time, when Venm is at a good diftance from the 
Earth , than when flie is near thereto,! attentively obferv’d, when 
fiie was rifen fomewhat high above theH^m^and ffiined bright- 
ter s whether T could not difeern in Her feme part remarkable either 
by its brightnefs or obfeurity, among the reft, efpecially about 
a tne middle of her Diske. And this I did not in vaine ^ for, I dif- 
cover’d at laft towards the middle of her Body a part dearer 
than the reft, by which one might judge of the Motion or the 
Reft of this Planet. 
The firft time I faw it, was okok 14^ 1 666 a h. 5. 45 *. p o m o 
and then this bright part was very near the Center, on thtJtifdrtfc 
fide. And at the fame timelobferved We (l- ward two ohfeure 
fpots, fomewhat oblong. But I could not then fee that refplen- 
dent part long enough, to concludeany thing from thence 5 nor 
was I able to fee any thing well of thofe parts till April 2%. 166 7. 
on which day, a quarter of an hour before Sun- riling I faw again 
a bright part , fcituated near the arid diftant from the 
, Southern Born a- little more than \ of its Diameter. And 
near the Eafiem Ring I faw a dark and fomewhat oblong 
fpot, which was nearer to the Northern than the Southern Horn! 
At the riling of the Sun I perceived , that this bright part 
was then no more fo near the Southern Horn, but diftant from 
it * of its Diameter. This gave me great fatisfadion s But 
T t.t z j 
' fe - - ^ . : 'S * 
