Bernoulli, Daniel, Hydrodynamica, sive De viribus et motibus fluidorum commentarii

Table of Notes

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            erit in caſu aliquo particulari aſtronomice refractionem definire, & </s>
            <s xml:id="echoid-s6535" xml:space="preserve">ex hoc re-
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            liquos calculo ſubducere. </s>
            <s xml:id="echoid-s6536" xml:space="preserve">Aſſumamus v. </s>
            <s xml:id="echoid-s6537" xml:space="preserve">gr. </s>
            <s xml:id="echoid-s6538" xml:space="preserve">in altitudine decem graduum re-
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            fractionem eſſe 5 min. </s>
            <s xml:id="echoid-s6539" xml:space="preserve">28 ſec. </s>
            <s xml:id="echoid-s6540" xml:space="preserve">cui hypotheſi plerique Aſtronomi Pariſiis adhærent.
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            </s>
            <s xml:id="echoid-s6541" xml:space="preserve">Inveniemus hancce refractionis tabulam.</s>
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          altit. ſid. appar. # refract. # altit. ſid. appar. # refract.
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          0 grad. # 34 min. # 53 ſec. # 50 grad. # 0 min. # 53 ſec.
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          5 # 9 - - - - # 59 - - # 55 # - - - - - # 44 {1/3}
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          10 # 5 - - - - # 28 - - # 60 # - - - - - # 36 {1/2}
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          15 # 3 - - - - # 44 - - # 65 # - - - - - # 29 {1/2}
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          20 # 2 - - - - # 52 - - # 70 # - - - - - # 23
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          25 # 2 - - - - # 12 - - # 75 # - - - - - # 17
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          30 # 1 - - - - # 47 - - # 80 # - - - - - # 11 {1/4}
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          35 # 1 - - - - # 29 - - # 85 # - - - - - - # 5 {1/2}
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          40 # 1 - - - - # 15 - - # 90 # - - - - - - # 0.
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          45 # 1 - - - - - # 3- -
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            <s xml:id="echoid-s6543" xml:space="preserve">Quia vero @refractiones ſequuntur rationem litteræ g. </s>
            <s xml:id="echoid-s6544" xml:space="preserve">id eſt, anguli re-
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            fractionis differentialis radii ſub angulo ſemirecto ex aëre naturali in vacuum in-
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            cidentis & </s>
            <s xml:id="echoid-s6545" xml:space="preserve">quia iſte angulus proportionalis eſt denſitati aëris naturalis, ſeu aëris,
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            quem obſervator reſpirat, patet ſi vel aër conſtanter ſimiliter vaporibus eſſet
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            oneratus (à quibus animum adhuc abſtraximus) non poſſe tamen fieri, quin
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            refractiones aſtronomicæ ſint admodum variabiles. </s>
            <s xml:id="echoid-s6546" xml:space="preserve">Majores nempe erunt in
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            ſuperficie maris quam in montibus, eritque notabilis differentia vel in me-
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            diocribus montium altitudinibus: </s>
            <s xml:id="echoid-s6547" xml:space="preserve">majores præterea erunt tempore frigido
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            quam calido, hæcque ſola cauſa in hiſce terris refractiones minimum quarta
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            parte augere poteſt: </s>
            <s xml:id="echoid-s6548" xml:space="preserve">denique majores etiam erunt refractiones barometro al-
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            to quam humili. </s>
            <s xml:id="echoid-s6549" xml:space="preserve">Poterunt autem ſi vapores nullo ſint obſtaculo, refractiones
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            omni tempore recte definiri, ſi inſtrumentum, quod §. </s>
            <s xml:id="echoid-s6550" xml:space="preserve">9. </s>
            <s xml:id="echoid-s6551" xml:space="preserve">deſcriptum fuit
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            quodque Fig. </s>
            <s xml:id="echoid-s6552" xml:space="preserve">57. </s>
            <s xml:id="echoid-s6553" xml:space="preserve">repræſentat ſimul adhibeatur cum barometro; </s>
            <s xml:id="echoid-s6554" xml:space="preserve">ſi enim alti-
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            tudinem mercurii in barometro dividas per altitudinem mercurii in altero in-
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            ſtrumento, habebis denſitatem aëris, cui cæteris paribus refractio proportio-
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            nalis eſt facienda. </s>
            <s xml:id="echoid-s6555" xml:space="preserve">Neque dubito, quin refractio ſolis minor ſit refractionibus
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            reliquorum ſiderum, quod calor ſolis aërem non mediocriter expandit aëriſ-
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            que denſitatem diminuit.</s>
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