Salusbury, Thomas
,
Mathematical collections and translations (Tome I)
,
1667
Text
Text Image
Image
XML
Thumbnail overview
Document information
None
Concordance
Figures
Thumbnails
Page concordance
<
1 - 30
31 - 60
61 - 90
91 - 120
121 - 150
151 - 180
181 - 210
211 - 240
241 - 270
271 - 300
301 - 330
331 - 360
361 - 390
391 - 420
421 - 450
451 - 480
481 - 510
511 - 540
541 - 570
571 - 600
601 - 630
631 - 660
661 - 690
691 - 701
>
Scan
Original
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
<
1 - 30
31 - 60
61 - 90
91 - 120
121 - 150
151 - 180
181 - 210
211 - 240
241 - 270
271 - 300
301 - 330
331 - 360
361 - 390
391 - 420
421 - 450
451 - 480
481 - 510
511 - 540
541 - 570
571 - 600
601 - 630
631 - 660
661 - 690
691 - 701
>
page
|<
<
of 701
>
>|
<
archimedes
>
<
text
>
<
body
>
<
chap
>
<
p
type
="
main
">
<
s
>
<
pb
xlink:href
="
040/01/220.jpg
"
pagenum
="
202
"/>
turn round, ſtaying there above, and moving along with the
<
lb
/>
urnal converſion. </
s
>
<
s
>Now I tell him, that that ſame ball falling from
<
lb
/>
the concave unto the centre, will acquire a degree of velocity
<
lb
/>
much more than double the velocity of the diurnal motion of the
<
lb
/>
Lunar concave; and this I will make out by ſolid and not
<
lb
/>
<
arrow.to.target
n
="
marg404
"/>
<
lb
/>
tinent ſuppoſitions. </
s
>
<
s
>You muſt know therefore that the grave
<
lb
/>
body falling and acquiring all the way new velocity according
<
lb
/>
to the proportion already mentioned, hath in any whatſoever
<
lb
/>
place of the line of its motion ſuch a degree of velocity, that if it
<
lb
/>
ſhould continue to move therewith, uniformly without farther
<
lb
/>
encreaſing it; in another time like to that of its deſcent, it would
<
lb
/>
paſſe a ſpace double to that paſſed in the line of the precedent
<
lb
/>
motion of deſcent. </
s
>
<
s
>And thus for example, if that ball in coming
<
lb
/>
from the concave of the Moon to its centre hath ſpent three hours,
<
lb
/>
22 min.
<
emph
type
="
italics
"/>
prim.
<
emph.end
type
="
italics
"/>
and 4 ſeconds, I ſay, that being arrived at the
<
lb
/>
tre, it ſhall find it ſelf conſtituted in ſuch a degree of velocity, that
<
lb
/>
if with that, without farther encreaſing it, it ſhould continue to
<
lb
/>
move uniformly, it would in other 3 hours, 22 min.
<
emph
type
="
italics
"/>
prim.
<
emph.end
type
="
italics
"/>
and
<
lb
/>
4 ſeconds, paſſe double that ſpace, namely as much as the whole
<
lb
/>
diameter of the Lunar Orb; and becauſe from the Moons
<
lb
/>
cave to the centre are 196000 miles, which the ball paſſeth in 3
<
lb
/>
hours 22
<
emph
type
="
italics
"/>
prim.
<
emph.end
type
="
italics
"/>
min. </
s
>
<
s
>and 4 ſeconds, therefore (according to what
<
lb
/>
hath been ſaid) the ball continuing to move with the velocity
<
lb
/>
which it is found to have in its arrival at the centre, it would
<
lb
/>
paſſe in other 3 hours 22 min. </
s
>
<
s
>prim. </
s
>
<
s
>and 4 ſeconds, a ſpace
<
lb
/>
ble to that, namely 392000 miles; but the ſame continuing in
<
lb
/>
the concave of the Moon, which is in circuit 1232000 miles, and
<
lb
/>
moving therewith in a diurnal motion, it would make in the ſame
<
lb
/>
time, that is in 3 hours 22 min. </
s
>
<
s
>prim. </
s
>
<
s
>and 4 ſeconds, 172880
<
lb
/>
miles, which are fewer by many than the half of the 392000
<
lb
/>
miles. </
s
>
<
s
>You ſee then that the motion in the concave is not as the
<
lb
/>
modern Author ſaith, that is, of a velocity impoſſible for the
<
lb
/>
ing ball to partake of,
<
emph
type
="
italics
"/>
&c.
<
emph.end
type
="
italics
"/>
</
s
>
</
p
>
<
p
type
="
margin
">
<
s
>
<
margin.target
id
="
marg404
"/>
<
emph
type
="
italics
"/>
The falling
<
lb
/>
able if it move with
<
lb
/>
a degree of
<
lb
/>
ty acquired in a
<
lb
/>
like time with an
<
lb
/>
uniform motion, it
<
lb
/>
ſhall paß a ſpace
<
lb
/>
double to that
<
lb
/>
ſed with the
<
lb
/>
leratedmotion.
<
emph.end
type
="
italics
"/>
</
s
>
</
p
>
<
p
type
="
main
">
<
s
>SAGR. </
s
>
<
s
>The diſcourſe would paſs for current, and would give
<
lb
/>
me full ſatisfaction, if that particular was but ſalved, of the
<
lb
/>
ving of the moveable by a double ſpace to that paſſed in falling
<
lb
/>
in another time equal to that of the deſcent, in caſe it doth continue
<
lb
/>
to move uniformly with the greateſt degree of velocity acquired
<
lb
/>
in deſcending. </
s
>
<
s
>A propoſition which you alſo once before
<
lb
/>
ſed as true, but never demonſtrated.</
s
>
</
p
>
<
p
type
="
main
">
<
s
>SALV. </
s
>
<
s
>This is one of the demonſtrations of
<
emph
type
="
italics
"/>
Our Friend,
<
emph.end
type
="
italics
"/>
and
<
lb
/>
you ſhall ſee it in due time; but for the preſent, I will with ſome
<
lb
/>
conjectures (not teach you any thing that is new, but) remember you
<
lb
/>
of a certain contrary opinion, and ſhew you, that it may haply ſo be.
<
lb
/>
</
s
>
<
s
>A bullet of lead hanging in a long and fine thread faſtened to the </
s
>
</
p
>
</
chap
>
</
body
>
</
text
>
</
archimedes
>