Musschenbroek, Petrus van, Physicae experimentales, et geometricae de magnete, tuborum capillarium vitreorumque speculorum attractione, magnitudine terrae, cohaerentia corporum firmorum dissertationes: ut et ephemerides meteorologicae ultraiectinae

Table of handwritten notes

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        <div xml:id="echoid-div122" type="section" level="1" n="122">
          <head xml:id="echoid-head131" xml:space="preserve">DE ACU INCLINATORIA.</head>
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            <s xml:id="echoid-s4420" xml:space="preserve">Vulgarium Verſoriorum horizontalium centrum gravitatis & </s>
            <s xml:id="echoid-s4421" xml:space="preserve">mo-
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            tus non eſt unum idemque punctum, ſed elevatius eſt centrum mo-
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            tus in ænei capituli excavati vertice, ſupra quem movetur, hinc
              <lb/>
            ſimulac Verſorium alterutro latere deprimitur, centrum gravitatis
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            elevatur ab oppofitâ parte, adeoque gravitas totius Verſorii iterum
              <lb/>
            deſcendere nitetur, atque hæc ita agendo in vim deprimentem Ver-
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            ſorii, impedit quominus accurate quantitas Inclinationis obſervari
              <lb/>
            queat, ideo vulgare Verſorium huic uſui ineptum eſt, aliudque di-
              <lb/>
            verſæ fabricandum erat formæ, cujus centrum motus & </s>
            <s xml:id="echoid-s4422" xml:space="preserve">gravitatis
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            unum idemque punctum foret: </s>
            <s xml:id="echoid-s4423" xml:space="preserve">Normannus acum conſtruxit ob-
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            longam, per cujus centrum gravitatis axem tranſfixit, quemadmo-
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            dum per Libræ jugum fieriſolet: </s>
            <s xml:id="echoid-s4424" xml:space="preserve">tum Acu Magneti affricta, & </s>
            <s xml:id="echoid-s4425" xml:space="preserve">axe
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            utrimque impoſito vitreo plano, deprehendit partem Boream incli-
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            naſſe Londini 71 gradibus, 50 Minutis. </s>
            <s xml:id="echoid-s4426" xml:space="preserve">Anno 1576. </s>
            <s xml:id="echoid-s4427" xml:space="preserve">Leotaudus,
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            improbata procul dubio Normanni machinâ, aliam invenit, quam
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            nos exhibemus Tab. </s>
            <s xml:id="echoid-s4428" xml:space="preserve">7. </s>
            <s xml:id="echoid-s4429" xml:space="preserve">fig. </s>
            <s xml:id="echoid-s4430" xml:space="preserve">10. </s>
            <s xml:id="echoid-s4431" xml:space="preserve">Eſt H I Acus oblonga, ab utraque
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            parte ſui axeos E F æque gravis: </s>
            <s xml:id="echoid-s4432" xml:space="preserve">axis excipitur ab annulo cupreo
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            D G E F, qui ex ſeta equina A D ſuſpenditur; </s>
            <s xml:id="echoid-s4433" xml:space="preserve">medius in circulo
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            æneo A K B C L, in 360 gradus diviſo, quorum initium eſt in ho-
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            rizontali K L, ponduſculum E annulo annexum ſuâ gravitate hunc
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            in ſitu ad horizontem perpendiculari dirigit; </s>
            <s xml:id="echoid-s4434" xml:space="preserve">hac machinâ nonnulli
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            Inclinationem Acus obſervaverunt, non tamen accurate, quia non-
              <lb/>
            nullis vitiis eſt ſubjecta, nec ob Acus brevitatem, utpote qui 3 vel
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            4 pollicum modo exiſtit, bene Inclinatio in gradibus & </s>
            <s xml:id="echoid-s4435" xml:space="preserve">minutis
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            obſervari poteſt: </s>
            <s xml:id="echoid-s4436" xml:space="preserve">præterea ope ponduſculi E non exacte poteſt con-
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            ſpici Nadir, imo attritus axeos G F in annulo ſupra idem metallum
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            mobilitatem acus adeo imminuit, ut vera Inclinatio obtineri nequeat.
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            </s>
            <s xml:id="echoid-s4437" xml:space="preserve">Hiſce defectibus obſervatis aliam compoſui machinam multo majo-
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            rem, cui Acus longiſſimæ imponi poterant, ut mobilitatem earum
              <lb/>
            nanciſcerer ſummam, & </s>
            <s xml:id="echoid-s4438" xml:space="preserve">ſimul Inclinationem notarem exactiſſime,
              <lb/>
            machinam repræſentat Tabula 8. </s>
            <s xml:id="echoid-s4439" xml:space="preserve">Eſt A A A Tabula lignea qua-
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            drata, cujus quodlibet latus A A eſt 26 pollicum: </s>
            <s xml:id="echoid-s4440" xml:space="preserve">huic inſculpti
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            ſunt tres quadrantes circulorum concentricorum G G, H H, K </s>
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