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

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              <s>
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              Weſt, nor as you would have it, upon the Piece, but rather far
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              diſtant towards the Eaſt. </s>
              <s>For according to your explanation, it
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              would have two motions, the which would with one conſent carry
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              it thitherward, to wit, the common motion of the Earth, which
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              carrieth the Piece and the ball from C A towards E D; and the
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              fire which carrieth it by the inclined line B D, both motions
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              wards the Eaſt, and therefore they are ſuperiour to the motion of
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              the Earth.</s>
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              <s>SAGR. </s>
              <s>Not ſo, Sir. </s>
              <s>The motion which carrieth the ball
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              wards the Eaſt, cometh all from the Earth, and the fire hath no
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              part at all therein: the motion which mounteth the ball upwards,
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              is wholly of fire, wherewith the Earth hath nothing to do. </s>
              <s>And
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              that it is ſo, if you give not fire, the ball will never go out of the
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              Piece, nor yet riſe upwards a hairs breadth; as alſo if you make
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              the Earth immoveable, and give fire, the ball without any
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              nation ſhall go perpendicularly upwards. </s>
              <s>The ball therefore
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              ving two motions, one upwards, and the other in gyration, of both
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              which the tranſverſe line B D is compounded, the impulſe upward
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              is wholly of fire, the circular cometh wholly from the Earth, and
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              is equal to the Earths motion: and being equal to it, the ball
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              maintaineth it ſelf all the way directly over the mouth of the
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              Piece, and at laſt falleth back into the ſame: and becauſe it
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              ways obſerveth the erection of the Piece, it appeareth alſo
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              nually over the head of him that is near the Piece, and therefore
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              it appeareth to mount exactly perpendicular towards our Zenith,
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              or vertical point.</s>
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              <s>SIMP. </s>
              <s>I have yet one doubt more remaining, and it is, that in
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              regard the motion of the ball is very ſwift in the Piece, it ſeems
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              not poſſible, that in that moment of time the tranſpoſition of the
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              Piece from C A to A D ſhould confer ſuch an inclination upon
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              the tranſverſe line C D, that by means thereof, the ball when it
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              cometh afterwards into the air ſhould be able to follow the courſe
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              of the Earth.</s>
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              <s>SAGR. </s>
              <s>You err upon many accounts; and firſt, the inclination
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              of the tranſverſe line C D, I believe it is much greater than you
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              take it to be, for I verily think that the velocity of the Earths
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              tion, not onely under the Equinoctial, but in our paralel alſo, is
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              greater than that of the ball whilſt it moveth in the Piece; ſo that
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              the interval C E would be abſolutely much bigger than the whole
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              length of the Piece, and the inclination of the tranſverſe line
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              ſequently bigger than half a right angle: but be the velocity of
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              the Earth more, or be it leſs, in compariſon of the velocity of the
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              fire, this imports nothing; for if the velocity of the Earth be ſmall,
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              and conſequently the inclination of the tranſverſe line be little
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              alſo; there is then alſo need but of little inclination to make the </s>
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