Galilei, Galileo - Mechanics

Galilei, Galileo, Mechanics, 1665

None
Concordance
Figures
Thumbnails

List of thumbnails

31	32
33	34
35	36
37	38
39	40

Simple Metals, that is, the Gold and the Silver, each of the ſame
weight as the Mixture, although he doth not ſay ſo; which may
be collected in that he marketh the ballance only betwixt the
Terms of the Gold and the Silver, which is the cauſe of the great
facility in reſolving the Problem by only counting the
Wyers.

One might take the pure Gold, and pure Silver of the ſame
weight, in reſpect of one another, but yet different from the
weight of the Mixture, that is, either more or leſs grave than the
Mixt Metal: and being equal in weight to one another they
might ſhew the proportion of the Maſs of the Gold to that of the
Silver; but yet with this difference, that the more grave will ſhew
the ſaid proportion more exactly than the ſmall and leſs grave.
But the Simple and pure Metals not being of the ſame weight as
the Compound, it will be neceſſary, having found the proportion
of the Maſs of the Gold to that of the Silver; to find by numbers
proportionally the exact quantity of each of the two Metals com-
pounding the Mixture.

A man may likewiſe uſe the quantity of the ſimple Metals ac-
cording to neceſſity and convenience, although of different
Weights, both as to each other, and to the Mixture, provided that
each of them be pure in its kind: but then we muſt after-
wards by numbers find the proportion of the Maſſes of the two
Simple ones of equal weight (which is ſoon done, taking them of
equal weight as was ſaid before) and then according to this pro-
portion to find, by means of the Weight, and of the Maſs of the
Compound Metal, the diſtinct quantity of each of the two Sim-
ple ones that make the Compoſition: of each of which Caſes
examples might be given. But to conclude, if the pure Gold,
and pure Silver, and the Mixt Metal ſhould be of equal Maſs,
they would be unequal in Weight, and it would not need to
weigh them in the Water, for being of equal Bulk, the differen-
ces of their Weights in the Air and in the Water would be alſo
equal: for the difference of the weight of any Body in the Air
to its weight in the Water, is alwaies equal to the Weight of ſo
much Water as equalleth the ſame Body in Maſs, by Archimedes
his fifth Propoſition, De ijs quæ vehuntur in aqua.

And laſt of all, the Simple and pure Metals may have the ſame
proportion in Gravity, mutually or reciprocally, as their Bodies
have in Bulk: In which caſe, as well the Maſs, found by help of
the weight in Water, or by any other meanes, as their Weight in
the Air ſhall ſhew the proportion of their Specifical Gravities; as
their Weights in the Water do when their Weights in the Air
are equal; but yet alternately weighed: that is to ſay, the Spe-
cifical Gravity of the Gold ſhall have ſuch proportion to the

Text layer

Text normalization

Search