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

Page concordance

< >
Scan Original
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
< >
page |< < of 701 > >|
    <archimedes>
      <text>
        <body>
          <chap>
            <p type="main">
              <s>
                <pb xlink:href="040/01/245.jpg" pagenum="227"/>
              downwards, and alſo forwards or backwards ten or fifteen fathom,
                <lb/>
              keeping it all the while parallel to its ſelf, the viſive ray cannot
                <lb/>
              ſtray from the point obſerved in the object, more than thoſe
                <lb/>
              teen fathom; and becauſe in a diſtance of eight or ten miles, the
                <lb/>
              Inſtrument takes in a much greater ſpace than the Gally or other
                <lb/>
              Veſſel kenn'd; therefore that ſmall mutation ſhall not make me
                <lb/>
              loſe ſight of her. </s>
              <s>The impediment therefore, and the cauſe of
                <lb/>
              loſing the object cannot befall us, unleſſe upon the mutation made
                <lb/>
              angularly; ſince that
                <emph type="italics"/>
              Teleſcopes
                <emph.end type="italics"/>
              tranſportation higher or lower, to
                <lb/>
              the right, or to the left, by the agitation of the ſhip, cannot import
                <lb/>
              any great number of fathomes. </s>
              <s>Now ſuppoſe that you had two
                <lb/>
                <emph type="italics"/>
              Teleſcopes
                <emph.end type="italics"/>
              fixed, one at the Partners cloſe by the Deck, and the
                <lb/>
              ther at the round top, nay at the main top, or main top-gallant
                <lb/>
              top, where you hang forth the
                <emph type="italics"/>
              Pennon
                <emph.end type="italics"/>
              or ſtreamer, and that they
                <lb/>
              be both directed to the Veſſel that is ten miles off, tell me,
                <lb/>
              ther you believe that any agitation of the ſhip, & inclination of the
                <lb/>
              Maſt, can make greater changes, as to the angle, in the higher tube,
                <lb/>
              than in the lower? </s>
              <s>One wave ariſing, the prow will make the main
                <lb/>
              top give back fifteen or twenty fathom more than the foot of the
                <lb/>
              Maſt, and it ſhall carry the upper tube along with it ſo greata ſpace,
                <lb/>
              & the lower it may be not a palm; but the angle ſhall change in one
                <lb/>
              Inſtrument aſwell as in the other; and likewiſe a ſide-billow ſhall
                <lb/>
              bear the higher tube an hundred times as far to the Larboard or
                <lb/>
              Starboard, as it will the other below; but the angles change not at
                <lb/>
              all, or elſe alter both alike. </s>
              <s>But the mutation to the right hand or
                <lb/>
              left, forwards or backwards, upwards or downwards, bringeth no
                <lb/>
              ſenſible impediment in the kenning of objects remote, though the
                <lb/>
              alteration of the angle maketh great change therein; Therefore it
                <lb/>
              muſt of neceſſity be confeſſed, that the uſe of the
                <emph type="italics"/>
              Teleſcope
                <emph.end type="italics"/>
              on the
                <lb/>
              round top is no more difficult than upon the Deck at the Partners;
                <lb/>
              ſeeing that the angular mutations are alike in both places.</s>
            </p>
            <p type="main">
              <s>SALV. </s>
              <s>How much circumſpection is there to be uſed in affirming
                <lb/>
              or denying a propoſition? </s>
              <s>I ſay again, thar hearing it reſolutely
                <lb/>
              med, that there is a greater motion made on the Maſts top, than at
                <lb/>
              its partners, every one will perſwade himſelf, that the uſe of the
                <emph type="italics"/>
                <lb/>
              leſcope
                <emph.end type="italics"/>
              is much more difficult above than below. </s>
              <s>And thus alſo I w
                <lb/>
              ill excuſe thoſe Philoſophers, who grow impatient and fly out into
                <lb/>
              paſſion againſt ſuch as will not grant them, that that Cannon bullet
                <lb/>
              which they cleerly ſee to fall in a right line perpendicularly, doth
                <lb/>
              abſolutely move in that manner; but will have its motion to be by
                <lb/>
              an arch, and alſo very much inclined and tranſverſal: but let us
                <lb/>
              leave them in theſe labyrinths, and let us hear the other objections,
                <lb/>
              that our Author in hand brings againſt
                <emph type="italics"/>
              Copernicus.
                <emph.end type="italics"/>
              </s>
            </p>
            <p type="main">
              <s>SIMP. </s>
              <s>The Author goeth on to demonſtrate that in the
                <lb/>
              ctrine of
                <emph type="italics"/>
              Copernicus,
                <emph.end type="italics"/>
              it is requiſite to deny the Senſes, and the </s>
            </p>
          </chap>
        </body>
      </text>
    </archimedes>
Impressum