Salusbury, Thomas
,
Mathematical collections and translations (Tome I)
,
1667
Text
Text Image
Image
XML
Thumbnail overview
Document information
None
Concordance
Figures
Thumbnails
page
|<
<
of 701
>
>|
<
archimedes
>
<
text
>
<
body
>
<
chap
>
<
p
type
="
main
">
<
s
>
<
pb
xlink:href
="
040/01/978.jpg
"
pagenum
="
284
"/>
with a Machine to overcome a Reſiſtance, though great, with a
<
lb
/>
ſmall Force, in regard, that we ſhall manifeſtly prove that the ſame
<
lb
/>
Force placed in F, might in the ſame Time conveigh the ſame
<
lb
/>
Weight, with the ſame Motion, unto the ſame Diſtance, without
<
lb
/>
any Machine at all: For ſuppoſing, for example, that the Reſiſtance
<
lb
/>
of the Grave H be ten times greater than the Force placed in F, it
<
lb
/>
<
figure
id
="
id.040.01.978.1.jpg
"
xlink:href
="
040/01/978/1.jpg
"
number
="
188
"/>
<
lb
/>
will be requiſite for the mo
<
lb
/>
ving of the ſaid Reſiſtance,
<
lb
/>
that the Line F B be decuple
<
lb
/>
to B D; and conſequently,
<
lb
/>
that the Circumference of the
<
lb
/>
Circle F G C be alſo decuple
<
lb
/>
to the Circumference E A D:
<
lb
/>
and becauſe when the Force
<
lb
/>
ſhall be moved once along the
<
lb
/>
whole Circumference of the
<
lb
/>
Circle F G C, the Barrel EAD,
<
lb
/>
about which the Rope is be-laid which draweth the Weight, ſhall
<
lb
/>
likewiſe have given one onely turn; it is manifeſt, that the Weight
<
lb
/>
H ſhall not have been moved more than the tenth part of that way
<
lb
/>
which the Mover ſhall have gone. </
s
>
<
s
>If therefore the Force that is to
<
lb
/>
move a Reſiſtance that is greater than it ſelf, for ſuch an aſſigned
<
lb
/>
Space by help of this Machine, muſt of neceſſity move ten times as
<
lb
/>
far, there is no doubt, but that dividing that Weight into ten parts,
<
lb
/>
each of them ſhall be equall to the Force, and conſequently, might
<
lb
/>
have been tranſported one at a Time, as great a Space as that
<
lb
/>
which it ſelf did move, ſo that making ten journeys, each equal to
<
lb
/>
the Circumference E A D, it ſhall not have gone any farther than
<
lb
/>
if it did move but once alone about the Circumference F G C;
<
lb
/>
and ſhall have conveighed the ſame Weight H to the ſame Di
<
lb
/>
ſtance. </
s
>
<
s
>The benefit therefore that is to be derived from theſe
<
lb
/>
Machines is, that they carry all the Weight together, but not with
<
lb
/>
leſſe Labour, or with greater Expedition, or a greater Way than
<
lb
/>
the ſame Force might have done conveying it by parcels.</
s
>
</
p
>
<
p
type
="
head
">
<
s
>Of PULLIES.</
s
>
</
p
>
<
p
type
="
main
">
<
s
>The Inſtruments, whoſe Natures are reducible unto the Bal
<
lb
/>
lance, as to their Principle and Foundation, and others little
<
lb
/>
differing from them, have been already deſcribed; now for
<
lb
/>
the underſtanding of that which we have to ſay touching Pullies,
<
lb
/>
it is requiſite, that we conſider in the firſt place another way to uſe
<
lb
/>
the Leaver, which will conduce much towards the inveſtigation of
<
lb
/>
the Force of Pullies, and towards the underſtanding of other Me
<
lb
/>
chanical Effects. </
s
>
<
s
>The uſe of the Leaver above declared ſuppoſed </
s
>
</
p
>
</
chap
>
</
body
>
</
text
>
</
archimedes
>