Opticks 1717 - Up

-*hi& might eolle S COi%hg fiOlll' the
feveral Points of the Paper, and make them converge
towards fo many other Points at the fame
difkance of fix Feet and one or two Inches on
the other fide of the Lens, and fo form the I-
mage of the coloured Paper upon a white Paper
placed there, after the fame manner that a
ens at a hole in a Window cait-s the Images of
broad upon a Sheet of white Paper ill
The aforefaid white Paper, e-
icular to the Horizon and, to the
ays which fell upon it from the Lens, I moved
fometimes towards the,kens, fometimes from
it, to find the places where the Images of the
blue and red parts of the coloul:ed Paper appeared
mofi diltin& Thofe places I eaiily knew by
the Images of the black Lines whicl! I had made
by winding the Sill;: about the Paper. For ;he
Images of those fine and flender Lines (which:
by reafon of their blacknefs were likeShadows
on .the Colours) were confuCed and fcarce viii-
Me, unlefs when the Colours on either fide ,of
each Line were terminated moit. diftin&ly., Noting
therefore 9 as diligent1 as I col,zld, the
places where the Images o E” the red and blue ~
halfs of the coloured Paper appeared mofi dif&x!?,
1c found that where the red half of the
Paper appeared dii’cin&, the blue half appeared
confufed, fo that the black Lines drawn upon
it could fcarce be feen ; and op the contrary%
where the blue half appeared moit difiin& the
red half appeared confufed, So that the ,black
Lines upon it were fcarce vifible. And between
the two places where thefe Images appeared
c-a
diRin&