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
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            <s xml:id="echoid-s10344" xml:space="preserve">
              <pb o="454" file="0468" n="468" rhead="INTRODUCTIO AD COHÆRENTIAM"/>
            vitreos diametri 1 {11/12} poll. </s>
            <s xml:id="echoid-s10345" xml:space="preserve">quorum alter baſin politam, alter aſpe-
              <lb/>
            ram habebat, hi ſibi impoſiti vix ſe attrahebant vi grani dimidii: </s>
            <s xml:id="echoid-s10346" xml:space="preserve">tum
              <lb/>
            tertium lævigatæ baſeos appoſui baſi lævi primi cylindri, qui am-
              <lb/>
            bo ſe attraxerunt vi 1 {1/2} grani: </s>
            <s xml:id="echoid-s10347" xml:space="preserve">duo cylindri cuprei ejusdem magnitu-
              <lb/>
            dinis, planæ baſeos ſed aſperæ, ſe non attraxerunt vi, quæ ope ac-
              <lb/>
            curatiſſimæ noſtræ bilancis obſervari potuit; </s>
            <s xml:id="echoid-s10348" xml:space="preserve">paulum lævigatæ,
              <lb/>
            attractio fuit {1/4} grani, ulterius politæ fuit æqualis grano 1. </s>
            <s xml:id="echoid-s10349" xml:space="preserve">politæ
              <lb/>
            quantum fieri poteſt, eos atterendo ſupra ſe mutuo interpoſito oleo
              <lb/>
            & </s>
            <s xml:id="echoid-s10350" xml:space="preserve">ſubtiliſſimo lapide Tripolitano, & </s>
            <s xml:id="echoid-s10351" xml:space="preserve">bene ſiccæ puræque ſe
              <lb/>
            attraxerunt vi granorum 2. </s>
            <s xml:id="echoid-s10352" xml:space="preserve">non tamen ſuperficies eo modo lævi-
              <lb/>
            gatiſſimæ ſunt factæ, quippe nondum ſplendebant. </s>
            <s xml:id="echoid-s10353" xml:space="preserve">Ex quibus
              <lb/>
            apparet, quare corpora aſperrimæ ſuperficiei ſibi impoſita non co-
              <lb/>
            hæreant, cum nimirum ſe in pauciſſimis attingant punctis, neque
              <lb/>
            vis attrahens ex toto egreſſa corpore eouſque ſeſe exporrigat, ut in
              <lb/>
            alterum corpus agat, idcirco attrahunt ſe minoribus viribus, quam
              <lb/>
            quæ ſub ſenſus cadunt. </s>
            <s xml:id="echoid-s10354" xml:space="preserve">Objectionibus plurimis ita obviam imus, cum
              <lb/>
            ſemper quæri ſoleat, data attractione, cur duo ligna ſibi impoſita non
              <lb/>
            cohæreant? </s>
            <s xml:id="echoid-s10355" xml:space="preserve">cur cubus metallicus alteri appoſitus non cohæreat,
              <lb/>
            ac ſi igne fuſus in unam maſſam uterque fuiſlet? </s>
            <s xml:id="echoid-s10356" xml:space="preserve">verum hæ evane-
              <lb/>
            ſcunt difficultates, ſi ad aſperitates ſuperficierum ſeſe attingentium
              <lb/>
            attendamus, impedientes quominus attractio ſenſibilis oriatur.</s>
            <s xml:id="echoid-s10357" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s10358" xml:space="preserve">Hinc intelligimus, quare corpora maxime cohærentia, uti A-
              <lb/>
            damas, Gemmæ, Silices, Vitra &</s>
            <s xml:id="echoid-s10359" xml:space="preserve">c. </s>
            <s xml:id="echoid-s10360" xml:space="preserve">diffracta ſuperſiciem ſplen-
              <lb/>
            dentem exhibeant, quæ ex planiſſimæ ſuperficiei partibus conſtare
              <lb/>
            videtur, quarum una alteram immediate attingere poteſt; </s>
            <s xml:id="echoid-s10361" xml:space="preserve">cum è
              <lb/>
            contrario corpora minoris firmitatis diffracta ſuperficiem exhibeant
              <lb/>
            aſperam & </s>
            <s xml:id="echoid-s10362" xml:space="preserve">inæqualem, utpote conſtantem ex corpuſculis, quorum
              <lb/>
            ſuperficies aſperiores etiam in paucioribus punctis attigerunt reli-
              <lb/>
            quas: </s>
            <s xml:id="echoid-s10363" xml:space="preserve">Et quia infinitis gradibus corpuſculorum ſuperficies quoad
              <lb/>
            aſperitatem inter ſe differre, & </s>
            <s xml:id="echoid-s10364" xml:space="preserve">majori minorive congruentia do-
              <lb/>
            nari poterunt, firmitas corporum majorum poteſt eſſe infinite varia.</s>
            <s xml:id="echoid-s10365" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s10366" xml:space="preserve">Non alienum erit ab hoc loco demonſtraſſe Cohærentiam in im-
              <lb/>
            mediato cöntactu corporum poſſe eſſe maximam, quæ exigua eſt
              <lb/>
            in parvo corporum a ſe intervallo, prout ſecundum aliquam pro-
              <lb/>
            portionem decreſcit attractio in diſtantiis: </s>
            <s xml:id="echoid-s10367" xml:space="preserve">Sit enim centrum cir-
              <lb/>
            culi A, T ab. </s>
            <s xml:id="echoid-s10368" xml:space="preserve">XVII. </s>
            <s xml:id="echoid-s10369" xml:space="preserve">fig. </s>
            <s xml:id="echoid-s10370" xml:space="preserve">14. </s>
            <s xml:id="echoid-s10371" xml:space="preserve">cujus radius eſt A D ſupra aream hujus </s>
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