liTo cover over both Ends of the Prifm with paper at feveral 
diftaoces from the middle - or Vi^ith moveable rings^to fee^how 
ihat will vary or divide the leogch of the figure^ infifted upon 
in the faid Theory. 
Uh To move the Prifni fo , as the End may turn about the 
middle being fteady. ■ 
I?. To move the prifniby ftioving tt.tiHfirft the onefide^than 
the midie^ than the other Ede pafs over che hGle^ obfeiviog the 
fame Parallehrm. 
TheOhfsrvationr^ made upon the fepropofals, , 
Suppofe the defign of the Propofer of theie Experiments 
_ is, CO have their events expreffed , with fuch obrervacions 
as may occur concerning them, i. Touching the//>/?, I have 
obferv'ds that the Solar image falh'ng on a paper placed at the 
focui of the Lens , was by the interpofed Pr lim drawn out lii 
length proportional to the Priiins reflexion ordiftaijce from 
xh.^p)pui^ And the chief obfervable here, which I remem- 
ber, was^^that the St^reight edges of che oblong image were 
diftin^ter than they would have been without the Lens. 
Confidering that the rays coming from the Planet Venus ViXQ 
muchlefiinclined one to another , than ihofe ^ !whi.ch come 
from the oppofire parts of the Suns dirque5 l oncetryedan 
experiment 6r two with A^r light. And to make it fiifficient- 
iy ftrong, I found it neceffary to colled it firft by a broad lens^ 
and then interpofing a Prifm between the /^?z/ and itsfocus ac 
fuch diftance, that all the light might pafs through the Prifm, 
I found, the which before appeared like a lucid poin t, to 
be drawn out into a long fplendid line by the Prifms reflexion^. . 
I have fomecimes defigiied to try^how a fixt^tar5feen through 
a long Telefcope, would appear by inter pofing a Prifm be- 
tween the Telefcopeand my eye^ But by the appearance of 
Fenusj^ viewed with mynaked eye through a Frifm^ 1 prelaae 
the event. ^ 
i.Concer'ning the/i^^c«iexperime;nr,t h^^ ^ 
ferved, that by covering both ends of the Piiira with Paper at 
feverai diftances from the midle , the breadth of the Solar 
image will be inereafed or dimimlhed as much , as is the aper- 
ture 
