Castelli, Benedetto, Of the mensuration of running waters, 1661

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              from the increaſing Lake, would not ſuffer it to increaſe in
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              height: I ſay therefore, that if we would rightly conſider this
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              doubt here propoſed, we ſhould, in the very conſideration of it,
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              ſee it reſolved; for, it being ſuppoſed that that liſt or border of
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              Banks which was to be occupied by the increaſe of the Lake, be
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              a Brace in breadth quite round the Lake, and that by reaſon of
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              its dryneſs it ſucks in water, and that by that means this propor­
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              tion of water co-operates not in raiſing of the Lake: It is abſo­
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              lutely neceſſary on the other hand, that we conſider, That the
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              Circuit of the water of the Lake being thirty miles, as its com­
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              monly held, that is to ſay, Ninety thouſand Braces of
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              Florence
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              in compaſs; and therefore admitting for true, that each Brace of
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              this Bank drink two quarts of water, and that for the ſpieading
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              it require three quarts more, we ſhall finde, that the whole agre­
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              gate of this portion of water, which is not imployed in the raiſing
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              of the Lake, will be four hundred and fifty thouſand Quarts of
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              water; and ſuppoſing that the Lake be ſixty ſquare miles, three
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              thouſand Braces long, we ſhall finde, that to diſpence the water
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              poſſeſt by the Bank about the Lake, above the total ſurface of
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              the Lake, it ought to be ſpread ſo thin, that one ſole quart of
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              water may over-ſpread ten thouſand ſquare Braces of ſurface:
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              ſuch a thinneſs, as muſt much exceed that of a leaf of beaten
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              Gold, and alſo leſs than that skin of water which covers the Bub­
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              bles of it: and ſuch would that be, which thoſe men would have
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              ſubſtracted from the riſing of the Lake: But again, in the ſpace
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              of a quarter of an hour at the beginning of the rain, all that
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              Bank is ſoaked by the ſaid rain, ſo that we need not for the
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              moiſtning of it, imploy a drop of that water which falleth into
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              the Lake. </s>
              <s>Beſides we have not brought to account that abun­
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              dance of water which runs in time of rain into the Lake, from
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              the ſteepneſs of the adjacent Hills and Mountains; which would
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              be enough to ſupply all our occaſions: So that, neither ought
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              we for this reaſon to queſtion our pretended riſing. </s>
              <s>And this
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              is what hath fallen in my way touching the conſideration of the
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                <emph type="italics"/>
              Thraſimenian
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              Lake.</s>
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              <s>After which, perhaps ſomewhat raſhly, wandring beyond my
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              bounds, I proceeded to another contemplation, which I will re­
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              late to you, hoping that you will receive it, as collected with
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              theſe cautions requiſite in ſuch like affairs; wherein we ought
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              not too poſitively to affirm any thing of our own heads for cer­
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              tain, but ought to ſubmit all to the ſound and ſecure delibera­
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              tion of the Holy Mother-Church, as I do this of mine, and all
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              others; moſt ready to change my judgement, and conform my
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              ſelf alwaies to the deliberations of my Superiors. </s>
              <s>Continu­</s>
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