Galilei, Galileo, Discourse concerning the natation of bodies, 1663

Table of figures

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              <s>THE OREME XII.</s>
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              That it is poſſible to fo m Solid Bodies, of what Figure
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              and greatneſs ſoever, that of their own Nature goe
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              to the Bottome; But by the help of the Air
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              tained in the Rampart, reſt without ſubmerging.
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              Solids of any
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              Figure &
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              neſſe, that
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              rally ſink, may
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              by help of the
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              Air in the
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              part ſwimme.</s>
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              <s>The truth of this Propoſition is ſufficiently manifeſt in all thoſe
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              Solid Figures, that determine in their uppermoſt part in a plane
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              Superficies: for making ſuch Figures of ſome Matter
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              cally as grave as the water, putting them into the water, ſo that the
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              whole Maſs be covered, it is manifeſt, that they ſhall reſt in all
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              places, provided, that ſuch a Matter equall in weight to the water,
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              may be exactly adjuſted: and they ſhall by conſequence, reſt or
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              lie even with the Levell of the water, without making any Rampart.
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              <s>If, therefore, in reſpect of the Matter, ſuch Figures are apt to reſt
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              without ſubmerging, though deprived of the help of the Rampart,
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              it is manifeſt, that they may admit ſo much encreaſe of Gravity,
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              (without encreaſing their Maſſes) as is the weight of as much water
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              as would be contained within the Rampart, that is made about their
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              upper plane Surface: by the help of which being ſuſtained, they
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              ſhall reſt afloat, but being bathed, they ſhall deſcend, having been
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              made graver than the water. </s>
              <s>In Figures, therefore, that determine
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              above in a plane, we may cleerly comprehend, that the Rampart
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              added or removed, may prohibit or permit the deſcent: but in thoſe
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              Figures that go leſſening upwards towards the top, ſome Perſons
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              may, and that not without much ſeeming Reaſon, doubt whether
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              the ſame may be done, and eſpecially by thoſe which terminate in a
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              very acute Point, ſuch as are your Cones and ſmall Piramids. </s>
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              ing theſe, therefore, as more dubious than the reſt, I will endeavour
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              to demonſtrate, that they alſo lie under the ſame Accident of going,
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              or not going to the Bottom, be they of any whatever bigneſs. </s>
              <s>Let
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              therefore the Cone be A B D, made of a matter
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              ſpecifically as grave as the water; it is manifeſt
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                <figure id="fig277" number="16"/>
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              that being put all under water, it ſhall reſt in
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              all places (alwayes provided, that it ſhall weigh
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              exactly as much as the water, which is almoſt
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              impoſſible to effect) and that any ſmall weight
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              being added to it, it ſhall ſink to the bottom:
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              but if it ſhall deſcend downwards gently, I ſay,
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              that it ſhall make the Rampart E S T O, and
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              that there ſhall ſtay out of the water the point A S T, tripple in
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              height to the Rampart E S: which is manifeſt, for the Matter of the </s>
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