Harriot, Thomas, Mss. 6788

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    <echo version="1.0RC">
      <text xml:lang="eng" type="free">
        <div type="section" level="1" n="1">
          <pb file="0971.jpg" o="486r" n="971"/>
          <head xml:space="preserve"> 1.
            <lb/>
          2. Of taking of altitudes of the sonne or
            <emph style="st">starre</emph>
          any
            <lb/>
          starre by the corsse staffe with more exactness
            <lb/>
          then hath ben used </head>
          <p>
            <s xml:space="preserve"> The
              <emph style="super">crosse</emph>
            staffe is
              <emph style="st">is</emph>
            the other instrument well knowne & used at sea
              <lb/>
              <emph style="st">but</emph>
              <emph style="super">and</emph>
            especially of starres. But as is
              <emph style="st">it used</emph>
            hath ben used heretofore the
              <lb/>
            seamasters commit great errors then sometimes they are aware of
              <lb/>
            from which errors if it be purged it is then of more apte & certayne use
              <lb/>
            also for the sonne then ether the Astrolabe or Ring which I meane in
              <lb/>
            this chapter to </s>
          </p>
          <p>
            <s xml:space="preserve"> The staffe is devided with presuppose that the end thereof
              <emph style="st">use</emph>
              <emph style="super">observing</emph>
            should
              <lb/>
            stand in the center of the sight. And though that cannot be performed, yet
              <lb/>
            the common practiser thinketh there is little errour in putting of it
              <lb/>
            close under
              <emph style="st">the</emph>
              <emph style="super">that</emph>
            ey they behold withall: some
              <emph style="st">under</emph>
            on the utmost corner of
              <lb/>
            that ey: some on the cheke bone:
              <emph style="st">&</emph>
              <emph style="super">&</emph>
            some on one side of the
              <emph style="st">nose</emph>
              <emph style="st">brid</emph>
            bridge of the nose.
              <lb/>
            All which placinges to some eyes, sometimes in some manner of observinges,
              <lb/>
            may prove true; & for the utmost corner of the ey to
              <emph style="st">unproportioned</emph>
            eyes, </s>
          </p>
          <p>
            <s xml:space="preserve"> But all
              <emph style="st">eyes</emph>
            men that have not a seat for the staffe iust agaynst the center
              <lb/>
            of the sight, as most men have not, must needs find a full altitude still
              <lb/>
            &
              <emph style="st">especially</emph>
            in great altitudes the errour wilbe
              <emph style="st">great</emph>
              <emph style="super">palpable</emph>
            as that it cannot
              <lb/>
            be borne withall, without artificiall correction; meaning allowance or
              <lb/>
            abatement, which hitherto have not ben made. And wher the seamen have
              <lb/>
            espied it
              <emph style="st">by</emph>
            ether by great difference from there recconings, or comparison with
              <lb/>
            there Astrolabe; for such great altitudes they geve over the </s>
          </p>
          <p>
            <s xml:space="preserve"> How this errour may be knowne & reformed I have demonstrated & taught
              <lb/>
            11 yeares past in my booke called Arcticon. Now only I will remember unto
              <lb/>
            you out of the same, that which I shewed you sometime to fore & sufficient for
              <lb/>
            your </s>
          </p>
          <p>
            <s xml:space="preserve"> The best place to set the end of your staffe is the utmost corner of the seat
              <lb/>
            of that ey which you mind to behold withall. because that place is firme &
              <lb/>
            certayne without offense to the eye.
              <lb/>
            And then how farre the end of
              <emph style="st">[???]</emph>
              <emph style="super">the</emph>
            staffe doth stand
              <emph style="st">from</emph>
              <emph style="super">behind</emph>
            the center of your
              <lb/>
            sight according as it hath ben already
              <emph style="st">when by yourself</emph>
            by a staffe
              <lb/>
            I have for the purpose: I have marked in a spare place of
              <emph style="st">these</emph>
            both your
              <lb/>
            staves nere the note of 90
              <emph style="super">Betwixt two parallel lines.</emph>
            And the same quantity I have found
              <lb/>
            to be in Cap. Whiddous; in Douglas the masters; & many
              <emph style="super">[???]</emph>
            else, as in yours
              <lb/>
            & mine. The which quantity hereafter for brevity & order sake according to
              <lb/>
            the nature of the thing I call the
              <emph style="st">per</emph>
            excentricity of the </s>
          </p>
          <p>
            <s xml:space="preserve"> The use of it is this: when you have according to the usuall manner
              <lb/>
            taken the sight of the sonne or starre & noted the place where the crosee stand
              <lb/>
              <emph style="st">you are to remove him further from you & by such a quantity as the excentri-</emph>
              <lb/>
              <emph style="st">city, which you may do by a pyre of compasses</emph>
            you are to consider what
              <lb/>
            sight that wilbe which is further from the ey by the quantity of the excentricity
              <lb/>
            which you may knowe by the helpe of a payre of compasses,
              <emph style="st">[???]</emph>
            & doth
              <lb/>
            alwayes make it lesse then the former. And that sight or altitude is
              <lb/>
            as true as if the end of your staffe did stand in the center of your </s>
          </p>
        </div>
      </text>
    </echo>
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