Harriot, Thomas, Mss. 6789

List of thumbnails

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831
831 (416r) 		832
832 (416v)
833
833 (417r) 		834
834 (417v)
835
835 (418r) 		836
836 (418v)
837
837 (419r) 		838
838 (419v)
839
839 (420r) 		840
840 (420v)
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page |< < (536r) of 1074 > >|
    <echo version="1.0RC">
      <text xml:lang="eng" type="free">
        <div type="section" level="1" n="1">
          <pb file="1069.jpg" o="536r" n="1069"/>
          <head xml:space="preserve"/>
          <p>
            <s xml:space="preserve"> And Because the
              <emph style="super">navigation &</emph>
            stirradge is made commonly by the
              <lb/>
            common compasse whose wires stand half a poynt
              <lb/>
            to the Eastwards of the North of the fly. It is necessary
              <lb/>
            that you also know the variation of this compasse,
              <lb/>
            otherwise sayling by such a compasse, you can make
              <lb/>
            no
              <emph style="st">ture</emph>
              <emph style="super">true</emph>
            reckoning of your course, nor
              <lb/>
            appoynt what stirradge ought to be </s>
          </p>
          <p>
            <s xml:space="preserve">
              <emph style="st">I shall</emph>
              <emph style="super">I will</emph>
            therefore geve this severall rule: having
              <lb/>
            noted the variation of the wires or north poynt
              <emph style="st">by</emph>
              <emph style="super">of one of</emph>
            the former
              <lb/>
              <emph style="st">rule & observation</emph>
            compasses which some call Meridionall
              <lb/>
            compasses; you shall find the variation of the north poynt
              <lb/>
            of the common compasse thus:
              <emph style="st">Reckon so many degrees</emph>
              <lb/>
              <emph style="st">as you former variation contrary wise to to the contrary</emph>
              <lb/>
              <emph style="st">way of the digit denominations</emph>
            </s>
          </p>
          <p>
            <s xml:space="preserve"> ffirst in that compasse that hath the moveable fly; move
              <lb/>
            it in such sort that his north poynt stand to the northward
              <lb/>
            of the wires half a poynt; then must the wires be to the east-
              <lb/>
            wards so much, & so that fly representeth the common </s>
          </p>
          <p>
            <s xml:space="preserve"> After reckon the degrees of your former variation from the
              <lb/>
            wires contrary to the denomination; that is to say if
              <lb/>
            the variation were East, reckon northward; or if west
              <lb/>
            reckon Eastward & where the degrees ened there is the
              <lb/>
            true north of the world; which being marked you may
              <lb/>
            then see both hos much &
              <emph style="st">wh</emph>
            which way the North of the
              <lb/>
              <emph style="st">grand</emph>
              <emph style="super">inner</emph>
            fly or common compasse doth </s>
          </p>
          <p>
            <s xml:space="preserve"> You may also do the same by that compasse which hath no
              <lb/>
            moveable fly, or
              <emph style="super">by</emph>
            any
              <emph style="st">such it is</emph>
              <lb/>
            drawne in any booke
              <lb/>
            so it
              <emph style="st">hath degrees</emph>
            be devided into degrees & that you make
              <lb/>
            a pricke or note half a poynt to the westwards of the north
              <lb/>
              <emph style="super">to</emph>
            represent the north of your common </s>
          </p>
          <p>
            <s xml:space="preserve"> But
              <emph style="st">of</emph>
              <emph style="super">whether</emph>
            our compasse
              <emph style="super">degrees or</emph>
            no degrees
              <emph style="st">are</emph>
              <emph style="super">may</emph>
            helpe your
              <lb/>
            self by addition & subtraction, remembring that 11 degrees
              <lb/>
            & a quarter make a poynt & 5 degrees & a half & half a quarter
              <lb/>
            do make half a </s>
          </p>
          <p>
            <s xml:space="preserve"> The example of this need be but short: The wires in the former
              <lb/>
            observation varied to the eastward 9 degrees & a half. halfe a
              <lb/>
            poynt to the northwards is the north of the common compasse; therefore abate
              <lb/>
            it out
              <emph style="super">of</emph>
              <math>
                <mstyle>
                  <mn>9</mn>
                  <mfrac>
                    <mrow>
                      <mn>1</mn>
                    </mrow>
                    <mrow>
                      <mn>2</mn>
                    </mrow>
                  </mfrac>
                </mstyle>
              </math>
            . there will remayne 4 degrees
              <emph style="st">had</emph>
            & so much doth your
              <lb/>
            common compasse vary in that plane;
              <emph style="st">& to the</emph>
            being lesse then half a poynt
              <lb/>
            & to the eastwards as before bycause
              <emph style="st">of the</emph>
            the half poynt was lesse
              <lb/>
            then the variation of the </s>
          </p>
        </div>
      </text>
    </echo>
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