HAP. xx.Of the Rule of Proportion, commonlycalled the Golden Rule.

His Nule is alſo called the rule ot thꝛes, foꝛ as muchas by thꝛee pꝛopoꝛtionall numbers knowne, it alwayſearcheth out the faurth pꝛopoꝛtionall, as ił nine yards otVeluet coſt eleuen pounds, what ſhall zz of the ſame colt.Mere are thꝛæ numbers giuen, and a fourth demaunded.Soꝛ the reſolution of this and all ſuch like, woꝛke by the

Rule enſuing.The Rule. iMultiplie the laſt number by the ſecond, and diuide thePꝛoduct by the firſt number, ſo wil vour Quotient and re-maine diſcotꝛer the fourth pꝛopoꝛtionall deſtred.

The demon tration of this Rule is grounded on the 19 Pro-poſſtion of the ſcauenthh Boche of the Seomretricall Elements.

Example.

Imultiplie 3j by 1x, there ariſeth 363, which diuided by

9, peeldeth in the Quotient 40, and in the remaine;, which

reduced, maketh, J conclude therloꝛe zz vards ol the ſameVeluet ſhall coſt foꝛtie Pounds, and a Poble.

Iq jardle o Ardles 27 7 7 150 5 75„ 4 115 214 Poundes.Wut in placing ot the thꝛeꝛ numbers this mut be obſer-ned, that the ſrſt and third be of one Denomination, as inthis queſtion they are both Veluet, and that the numbers

pꝛoponed foꝛ a paterne, de ſirſt placed, and the number,

whole fellow you ſeeke, be alwapes placed lat. Here 4kearme firſt and laſt, accozding to our vſuall manner otwaiting from the lelt hand to the right, and not as in Nu-

meration,The

STRATIOTIcos. 2

—

1