Opticks 1717 - Up

3
id th$ iht% Shadows have three parallel
Fringes5 Bandsor Raqks of colour’d Light a&
jacent to $jeni; ,But if jhe Hole be enlarged
the Fringes grow broad and’rqn into one anotherj
fo th+t they cannot be difiinguiflz’d~ Thefe
broad Shadows and Fringes have been reckon’8
bv fame to proceed fr,dm the ordinary, refra”
d%ion of the Air, but without due exarninatio~
of the Matter.
Phsenome&n5
For the circumffarices of the
fo far as I have obferved them3
b-e, &s follows;
QbJ *. I niade in ti Piece of.Lead ti fmall
Hole with a Pin, whale breadth was the 426
part of in Inch. For zr of thafe Pins laid toA
ether took up the breadth of half an Inch;
!i? hrough this Hole I ‘let into my darken’d.
%hnmber a, beam of the Sun’sLight, and found.
that theShadows of Hairs, Thredj Pins, Strawsj
and fuch like flender Subfiances placed in this
beam of Light, were confi?lerably broader thati
theyought to be, if the Ra S’ of Light pan’e(!.
6n by thefe Bodies in right L ines. And partid
cularly a lWair of a Man:s Head, whole breadth
was but the 280th part of an Inch, being held
in this Light 9 tit the diilance of about twelve
Feet .fiom, the Hole3 did cftll: a Shadow ~hkh
At the d&u& of four Inches from the Hair
.~as the fixtieth part of tin,Inch brodd, that is,
above four times broader than the Hair, .and at
,$e &fiance ,of two Feet from the ]E-Pair WsiS aa
bout the eight and twentreth part of. an Inch
broad, that IS, ten times broader than the Hairs.
.&d at the &lance .of tea FeetJ was, the eighth
part of an Inch broad, tha.s;f times broader.
N‘or