Salusbury, Thomas, Mathematical collections and translations (Tome I), 1667

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              example, we ſee them whil'ſt they are alive to fly upwards, a thing
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              altogether impoſſible for them to do as they are grave bodies;
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              whereas being dead they can onely fall downwards; and
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              fore you hold that the reaſons that are of force in all the kinds of
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              projects above named, cannot take place in birds: Now this is
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              very true; and becauſe it is ſo,
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              Sagredus,
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              that doth not appear
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              to be done in thoſe projects, which we ſee the birds to do. </s>
              <s>For if </s>
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              from the top of a Tower you let fall a dead bird and a live one,
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              the dead bird ſhall do the ſame that a ſtone doth, that is, it ſhall
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              firſt follow the general motion diurnal, and then the motion of
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              deſcent, as grave; but if the bird let fall, be a live, what ſhall
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              hinder it, (there ever remaining in it the diurnal motion) from
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              ſoaring by help of its wings to what place of the Horizon it ſhall
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              pleaſe? </s>
              <s>and this new motion, as being peculiar to the bird, and
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              not participated by us, muſt of neceſſity be viſible to us; and if
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              it be moved by help of its wings towards the Weſt, what ſhall
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              hinder it from returning with a like help of its wings unto the
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              Tower. </s>
              <s>And, becauſe, in the laſt place, the birds wending its
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              flight towards the Weſt was no other than a withdrawing from
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              the diurnal motion, (which hath, ſupppoſe ten degrees of velocity)
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              one degree onely, there did thereupon remain to the bird whil'ſt
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              it was in its flight nine degrees of velocity, and ſo ſoon as it did
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              alight upon the the Earth, the ten common degrees returned to it,
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              to which, by flying towards the Eaſt it might adde one, and with
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              thoſe eleven overtake the Tower. </s>
              <s>And in ſhort, if we well
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              ſider, and more narrowly examine the effects of the flight of
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              birds, they differ from the projects ſhot or thrown to any part of
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              the World in nothing, ſave onely that the projects are moved by an
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              external projicient, and the birds by an internal principle. </s>
              <s>And
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              here for a final proof of the nullity of all the experiments before
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              alledged, I conceive it now a time and place convenient to
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              demonſtrate a way how to make an exact trial of them all.
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              </s>
              <s>Shut your ſelf up with ſome friend in the grand Cabbin between
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              the decks of ſome large Ship, and there procure gnats, flies, and
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              ſuch other ſmall winged creatures: get alſo a great tub (or
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              other veſſel) full of water, and within it put certain fiſhes; let
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              alſo a certain bottle be hung up, which drop by drop letteth forth
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              its water into another bottle placed underneath, having a narrow
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              neck: and, the Ship lying ſtill, obſerve diligently how thoſe ſmall
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              winged animals fly with like velocity towards all parts of the
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              bin; how the fiſhes ſwim indifferently towards all ſides; and how
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              the diſtilling drops all fall into the bottle placed underneath. </s>
              <s>And
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              caſting any thing towards your friend, you need not throw it with
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              more force one way then another, provided the diſtances be equal:
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              and leaping, as the ſaying is, with your feet cloſed, you will reach </s>
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