Galilei, Galileo
,
Discourse concerning the natation of bodies
,
1663
Text
Text Image
XML
Document information
None
Concordance
Figures
Thumbnails
List of thumbnails
<
1 - 10
11 - 20
21 - 30
31 - 40
41 - 50
51 - 60
61 - 70
71 - 77
>
51
52
53
54
55
56
57
58
59
60
<
1 - 10
11 - 20
21 - 30
31 - 40
41 - 50
51 - 60
61 - 70
71 - 77
>
page
|<
<
of 77
>
>|
<
archimedes
>
<
text
>
<
body
>
<
chap
>
<
pb
pagenum
="
449
"/>
<
p
type
="
main
">
<
s
>Now let us ſee on which of theſe three dimenſions of the Solid
<
lb
/>
depends the terminating, what and how much the Maſs of that ought
<
lb
/>
to be, that ſo the aſſiſtance of the Air contiguous unto it, may ſuffice
<
lb
/>
to render it ſpecifically leſs grave than the water, whereupon it may
<
lb
/>
reſt without Submerſion. </
s
>
<
s
>It ſhall undoubtedly be found, that the
<
lb
/>
length and breadth have not any thing to do in the ſaid
<
lb
/>
tion, but only the height, or if you will the thickneſs: for, if we take
<
lb
/>
a Plate or Board, as for Example, of Ebony, whoſe Altitude hath
<
lb
/>
unto the greateſt poſſible Altitude of the Rampart, the proportion
<
lb
/>
above declared, for which cauſe it ſwims indeed, but yet not if we
<
lb
/>
never ſo little increaſe its thickneſs; I ſay, that retaining its
<
lb
/>
neſs, and encreaſing its Superficies to twice, four times, or ten times
<
lb
/>
its bigneſs, or dminiſning it by dividing it into four, or ſix, or
<
lb
/>
twenty, or a hundred parts, it ſhall ſtill in the ſame manner continue
<
lb
/>
to float: but encreaſing its thickneſs only a Hairs breadth, it will
<
lb
/>
alwaies ſubmerge, although we ſhould multiply the Superficies a
<
lb
/>
hundred and a hundred times. </
s
>
<
s
>Now foraſmuch as that this is a
<
lb
/>
Cauſe, which being added, we adde alſo the Effect, and being
<
lb
/>
ved, it is removed; and by augmenting or leſſening the length or
<
lb
/>
breadth in any manner, the effect of going, or not going to the
<
lb
/>
tom, is not added or removed: I conclude, that the greatneſs and
<
lb
/>
ſmalneſs of the Superficies hath no influence upon the Natation or
<
lb
/>
Submerſion. </
s
>
<
s
>And that the proportion of the Altitude of the
<
lb
/>
parts of Water, to the Altitude of the Solid, being conſtituted in
<
lb
/>
the manner aforeſaid, the greatneſs or ſmalneſs of the Superficies,
<
lb
/>
makes not any variation, is manifeſt from that which hath been above
<
lb
/>
demonſtrated, and from this, that,
<
emph
type
="
italics
"/>
The Priſms and Cylinders which
<
emph.end
type
="
italics
"/>
</
s
>
</
p
>
<
p
type
="
main
">
<
s
>
<
arrow.to.target
n
="
marg1513
"/>
<
lb
/>
<
emph
type
="
italics
"/>
have the ſame Baſe, are in proportion to one another as their heights:
<
emph.end
type
="
italics
"/>
<
lb
/>
Whence Cylinders or Prifmes, namely, the Board, be they great or
<
lb
/>
little, ſo that they be all of equall thickneſs, have the ſame proportion
<
lb
/>
to their Conterminall Air, which hath for Baſe the ſaid Superficies of
<
lb
/>
the Board, and for height the Ramparts of water; ſo that alwayes
<
lb
/>
of that Air, and of the Board, Solids are compounded, that in Gravity
<
lb
/>
equall a Maſs of water equall to the Maſs of the Solids, compounded
<
lb
/>
of Air, and of the Board: whereupon all the ſaid Solids do in the
<
lb
/>
ſame manner continue afloat. </
s
>
<
s
>We will conclude in the third place,
<
lb
/>
that,</
s
>
</
p
>
</
chap
>
</
body
>
</
text
>
</
archimedes
>