Salusbury, Thomas, Mathematical collections and translations (Tome I), 1667
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              Rope about the Axis of a Crane did not only hold it, that be­
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              ing drawn by the immenſe force of the weight, which it held, it
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              ſlipt nor ſhrunk not; but that moreover turning the Crane about,
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              the ſaid Axis with the ſole touch of the Rope which begirteth it,
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              did in the after-turnings, draw and raiſe up vaſt ſtones, whilſt the
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              ſtrength of a little Boy ſufficed to hold and ſtay the other end of
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              the ſame Cord. </s>
              <s>The other is at a plain, but cunning, Inſtrument found
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              out by a young Kinſman of mine, by which with a Cord he could
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              let himſelf down from a window without much gauling the palmes
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              of his hands, as to his great ſmart not long before he had done. </s>
              <s>For
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              the better underſtanding whereof, rake this Scheame: About ſuch
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              a Cylinder of Wood as A B, two Inches
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              thick, and ſix or eight Inches long, he cut a
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              hollow notch ſpirally, for one turn and a
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                <figure id="id.040.01.701.1.jpg" xlink:href="040/01/701/1.jpg" number="54"/>
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              half and no more, and of wideneſſe fit for
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              the Cord he would uſe; which he made to
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              enter through the notch at the end A, and
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              to come out at the other B, incircling after­
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              wards the Cylinder in a barrel or ſocket of
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              Wood, or rather Tin, but divided length­
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              waies, and made with Claſpes or Hinges to
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              open and ſhut at pleaſure: and then graſp­
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              ing and holding the ſaid Barrel or Caſe with
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              both his hands, the rope being made faſt
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              above, he hung by his arms; and ſuch was
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              the compreſſion of the Cord between the
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              moving Socket and the Cylinder, that at
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              pleaſure griping his hands cloſer he could
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              ſtay himſelf without deſcending, and ſlacking his hold a little, he
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              could let himſelf down as he pleaſed.</s>
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              An Hand-Pully
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              or Inſtrument in­
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              vented by an ama­
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              rous perſon to let
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              himſelf down from
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              any great height
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              with a Cord with­
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              out gauling his
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              hands.
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              <s>SALV. </s>
              <s>Aningenious invention verily, and for a full explanati­
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              on of its nature, me-thinks I diſcover, as it were by a ſhadow, the
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              light of ſome other additional diſcoveries: but I will not at this
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              time deviate any more from my purpoſe upon this particular: and
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              the rather in regard you are deſirous to hear my opinion of the
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              Reſiſtance of other Bodies againſt Fraction, whoſe texture is not
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              with threads, and fibrous ſtrings, as is that of Ropes, and moſt
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              kinds of Wood: but the connection of their parts ſeem to de­
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              pend on other Cauſes; which in my judgment may be reduced to
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              two heads; one is the much talked-of Repugnance that Nature
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              hath againſt the admiſſion of Vacuity: for another (this of Va­
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              cuity not ſufficing) there muſt be introduced ſome glue, viſcous
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              matter, or Cement, that tenaciouſly connecteth the Corpuſcles of
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              which the ſaid Body is compacted.</s>
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              Why ſuch Bodies
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              reſiſt Fraction that
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              are not connected
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              with Fibrous fila­
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              ments.
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              <s>I will firſt ſpeak of
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              Vacuity,
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              ſhewing by plain experiments, </s>
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