Opticks 1717 - Up

to, F all degrees of orange, at F the lllean be-
~YVC~X orange and JE~~OW, from F to G 211 degrees
of Y~OW, alld SO on. Let p be the tenter
of gravity of the Arch DE, &d 4, r9 $, Tr,
a, x, the centers of gravity of the Arches E F,
F G, G A, AR, I3 z’ and 6 D re$m!Iively, and
abcut thofe Cellters of gravity let Circles proportional
to the mmber of Rays of each Colouir
in the given Mixture be defcrib’d ; that is,
the Circle .p proportional to the number of the
red-making Rays in the Mixture, the Cir-& 4
proportional to the number of the orange-making
Rays in the Mixture, and fo of the r@,
Find the con&non center of gravity of al1 tbofe
C,ircles p, g, T> S, t, U, X. Let that center be
%; and from the center of the Circle A 19 F,
through Z to the circumference, drawing the
right Lkc 0 Y, the place of the PointY 111 the
~c1rmmfcrence fhall ihcw the Colour al-ifing
from the comyofition of all the Colours .in the
given Mixture, and the Line 0 Z Ml be proc
portional to the fiilncfs or jntenfenefs of the
Colour, that is, to its diilance from whitenefs,
As if Y fill1 in the middle between F md G,
the ~pnpounded Colo~r &all be the be& yeI-
10~; if y verge from the middle towards F
ilr f$, tllc ~on-pund Colour ihall accolldingly
be fl yellow, verging tower& orange or gyeen,
If Y, fill1 qh311 cl3c circuinfcrence the Co{our
fl1a11 be jlItellfc and florid in the higheit: degree ;
ff it fall ‘ill tllc l,lljd way between the* &cumference
and center, j:t Ml be but half i% J
jmsfe~ that is, it &all be fuch a.Colour as
JJ~Q~I]~ be xn~dc lpy dilutiiz the iptenkti ye@-w
. jK; 4, ., wtb
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