Galilei, Galileo
,
Mechanics
,
1665
Text
Text Image
XML
Document information
None
Concordance
Figures
Thumbnails
List of thumbnails
<
1 - 10
11 - 20
21 - 30
31 - 40
>
1
2
3
4
5
6
7
8
9
10
<
1 - 10
11 - 20
21 - 30
31 - 40
>
page
|<
<
of 40
>
>|
<
archimedes
>
<
text
>
<
body
>
<
chap
>
<
p
type
="
main
">
<
s
>
<
pb
xlink:href
="
070/01/026.jpg
"
pagenum
="
296
"/>
able hath upon the inclined Plane C A hath to its total Moment
<
lb
/>
wherewith it gravitates in the Perpendicular to the Horizon C P the
<
lb
/>
ſame proportion that the ſaid Line P C hath to C A. </
s
>
<
s
>And if thus it
<
lb
/>
be, it is manifeſt, that like as the Force that ſuſtai
<
lb
/>
neth the Weight in the Perpendiculation P C ought
<
lb
/>
<
figure
id
="
id.070.01.026.1.jpg
"
xlink:href
="
070/01/026/1.jpg
"
number
="
22
"/>
<
lb
/>
to be equal to the ſame, ſo for ſuſtaining it in the
<
lb
/>
inclined Plane C A, it will ſuffice that it be ſo much
<
lb
/>
leſſer, by how much the ſaid Perpendicular C P wan
<
lb
/>
teth of the Line C A: and becauſe, as ſometimes we
<
lb
/>
ſce, it ſufficeth, that the Force for moving of the
<
lb
/>
Weight do inſenſibly ſuperate that which ſuſtaineth it, therefore
<
lb
/>
we will infer this univerſal Propoſition, [That upon an Elevated
<
lb
/>
Plane the Force hath to the Weight the ſame proportion, as the
<
lb
/>
Perpendicular let fall from the Plane unto the Horizon hath to the
<
lb
/>
Length of the ſaid Plane.]</
s
>
</
p
>
<
p
type
="
margin
">
<
s
>
<
margin.target
id
="
marg1117
"/>
* Or along</
s
>
</
p
>
<
p
type
="
main
">
<
s
>Returning now to our firſt Intention, which was to inveſtigate
<
lb
/>
the Nature of the Screw, we will conſider the Triangle A B C, of
<
lb
/>
which the Line A B is Horizontal, B C perpendicular to the ſaid
<
lb
/>
Horizon, and A C a Plane elevated; upon which the Moveable D
<
lb
/>
ſhall be drawn by a Force ſo much leſs than it, by how much the
<
lb
/>
Line B C is ſhorter than C A: But to elevate or raiſe the ſaid
<
lb
/>
Weight along the ſaid Plane A C, is as much as if the Triangle
<
lb
/>
C A B ſtanding ſtill, the Weight
<
lb
/>
<
figure
id
="
id.070.01.026.2.jpg
"
xlink:href
="
070/01/026/2.jpg
"
number
="
23
"/>
<
lb
/>
D be moved towards C, which is
<
lb
/>
the ſame, as if the ſame Weight
<
lb
/>
never removing from the Perpen
<
lb
/>
dicular A E, the Triangle did
<
lb
/>
preſs forwards towards H. </
s
>
<
s
>For if
<
lb
/>
it were in the Site F H G, the
<
lb
/>
Moveable would be found to
<
lb
/>
have mounted the height A I.
<
lb
/>
Now, in fine, the primary Form and Eſſence of the Screw is no
<
lb
/>
thing elſe but ſuch a Triangle A C B, which being forced for
<
lb
/>
wards, ſhall work it ſelf under the Grave Body to be raiſed, and
<
lb
/>
lifteth it up, as we ſay, by the ^{*} head and ſhoulders. </
s
>
<
s
>And this was
<
lb
/>
<
arrow.to.target
n
="
marg1118
"/>
<
lb
/>
its firſt Original: For its firſt Inventor (whoever he was) conſi
<
lb
/>
dering how that the Triangle A B C going forwards raiſeth the
<
lb
/>
Weight D, he might have framed an Inſtrument like to the ſaid
<
lb
/>
Triangle, of a very ſolid Matter, which being thruſt forwards did
<
lb
/>
raiſe up the propoſed Weight: But afterwards conſidering better,
<
lb
/>
how that that ſame Machine might be reduced into a much leſſer
<
lb
/>
and more commodious Form, taking the ſame Triangle he twined
<
lb
/>
and wound it about the Cylinder A B C D in ſuch a faſhion, that
<
lb
/>
the height of the ſaid Triangle, that is the Line C B, did make the
<
lb
/>
Height of the Cylinder, and the Aſcending Plane did beget upon </
s
>
</
p
>
</
chap
>
</
body
>
</
text
>
</
archimedes
>