Castelli, Benedetto
,
Of the mensuration of running waters
,
1661
Text
Text Image
Image
XML
Thumbnail overview
Document information
None
Concordance
Figures
Thumbnails
page
|<
<
of 137
>
>|
<
archimedes
>
<
text
>
<
body
>
<
chap
>
<
p
type
="
main
">
<
s
>
<
pb
xlink:href
="
068/01/017.jpg
"
pagenum
="
3
"/>
derſtood nothing at all, of that which others pretended full and
<
lb
/>
clearly to underſtand. </
s
>
<
s
>And my doubt aroſe from my frequent
<
lb
/>
obſervation of many Trenches and Channels, which carry
<
lb
/>
water to turn Mills, in which Trenches, and Channels, the
<
lb
/>
water being meaſured, was found pretty deep; but if afterwards
<
lb
/>
the ſame water was meaſured in the fall it made to turn the
<
lb
/>
Wheel of the Mill, it was much leſſe, not amounting often to the
<
lb
/>
tenth part, nor ſometimes to the twentieth, inſomuch, that the
<
lb
/>
ſame running water came to be one while more, another while leſs
<
lb
/>
in meaſure, in divers parts of its Channel; and for that reaſon this
<
lb
/>
vulgar manner of meaſuring running Waters, as indeterminate and
<
lb
/>
uncertain, was by me juſtly ſuſpected, the meaſure being to be de
<
lb
/>
terminate, and the ſame. </
s
>
<
s
>And here I freely confeſſe that I had fin
<
lb
/>
gular help to reſolve this difficulty from the excellent & accurate
<
lb
/>
way of diſcourſing, as in allother matters, ſo alſo in this, of the
<
lb
/>
Right Honourable and Truly Noble Signior
<
emph
type
="
italics
"/>
Ciampoli,
<
emph.end
type
="
italics
"/>
Secretary
<
lb
/>
of the Popes ſecret affairs. </
s
>
<
s
>Who moreover, not ſparing ſor the coſts
<
lb
/>
of the ſame, generouſly gave me occaſion a few years paſt to try by
<
lb
/>
exact experiments that which paſt concerning this particular. </
s
>
<
s
>And
<
lb
/>
to explain all more clearly with an example; we ſuppoſe a Veſſel
<
lb
/>
filled with Water, as for inſtance a Butt, which is kept full, though
<
lb
/>
ſtill water runneth out, and the Water run out by two Taps equal
<
lb
/>
of bigneſſe, one put in the bottom of the Veſſel, and the other in
<
lb
/>
the upper part; it is manifeſt that in the time wherein from the
<
lb
/>
upper part ſhall iſſue a determinate meaſure of water ſrom
<
lb
/>
the inferiour part there ſhall iſſue four, five, and many more of
<
lb
/>
the ſame meaſures, according to the difference of the height of
<
lb
/>
the Taps, and the diſtance of the upper Tap from the Superfici
<
lb
/>
es and level of the water of the Veſſel: and all this will alwayes
<
lb
/>
follow, though, as hath been ſaid, the Taps be equal, and the
<
lb
/>
water in diſcharging keep the ſaid Taps alwayes full. </
s
>
<
s
>Where firſt
<
lb
/>
we note, that, although the meaſure of the Taps be equal, never
<
lb
/>
theleſſe there iſſueth from them in equal times unequal quantities
<
lb
/>
of water, And if we ſhould more attentively conſider this buſi
<
lb
/>
neſſe, we ſhould find, that the water by the lower Tap, run
<
lb
/>
neth and paſſeth with much greater velocity, then it doth by the
<
lb
/>
upper, whatever is the reaſon. </
s
>
<
s
>If therefore we would have
<
lb
/>
ſuch a quantity of Water diſcharge from the upper tap, as
<
lb
/>
would diſcharge from the neather in the ſame time, it is plain, that
<
lb
/>
either the upper Taps muſt be multiplyed in ſuch ſort, that ſo
<
lb
/>
many more Taps in number be placed above than below, as the
<
lb
/>
neather tap ſhall be more ſwift than the upper, or the upper Tap
<
lb
/>
made ſo much bigger than the nether, by how much that be
<
lb
/>
neath ſhall be more ſwift than that above; and ſo then in equal
<
lb
/>
times, the ſame quantity of Water ſhall diſcharge from the upper,
<
lb
/>
as doth from the neather part.</
s
>
</
p
>
</
chap
>
</
body
>
</
text
>
</
archimedes
>