Barrow, Isaac, Lectiones opticae & geometricae : in quibus phaenomenon opticorum genuinae rationes investigantur, ac exponuntur: et generalia curvarum linearum symptomata declarantur

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            ſtrentur. </s>
            <s xml:id="echoid-s8566" xml:space="preserve">Porrò, non abſimiliter ſi velocitatis gradus continuâ per
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            ſingula temporis inſtantia ſucceſſione, à quiete ad definitum gradum,
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            vel retrogradè, creſcere concipiantur, aut decreſcere juxta progreſſi-
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            onem numerorum quadraticorum repræſentatur tum optimè velocitas
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              <note position="left" xlink:label="note-0190-01" xlink:href="note-0190-01a" xml:space="preserve">Fig. 2.</note>
            aggregata, ſicut & </s>
            <s xml:id="echoid-s8567" xml:space="preserve">ſpatium hujuſmodi motu confectum, à comple-
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            mento Semiparabolæ, qualis eſt AEX, cujus vertex A quietem (ſeu
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            motûs ac temporis initium) tangens AE tempus definitum, linea BX
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            primum velocitatis accreſcentis gradum (qui ſe habet ut I.) </s>
            <s xml:id="echoid-s8568" xml:space="preserve">proxima
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            CX ſecundum gradum (habentem ſe ut 4.) </s>
            <s xml:id="echoid-s8569" xml:space="preserve">ſubſequens DX (qui ſe
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            habet ut 9.) </s>
            <s xml:id="echoid-s8570" xml:space="preserve">& </s>
            <s xml:id="echoid-s8571" xml:space="preserve">ità porrò uſque ad ultimum EX: </s>
            <s xml:id="echoid-s8572" xml:space="preserve">Id quod ex notiſſi-
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            ma parabolæ proprietate manifeſtum eſt. </s>
            <s xml:id="echoid-s8573" xml:space="preserve">Eodem planè modo quivis
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            ſuppoſiti velocitatis gradus, utcunque creſcentis aut decreſcentis,
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            continuo vel interruptè, quovis, inquam, imaginabili modo per
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            lineas rectas ad temporis repræſentatricem rectam applicatas certiſſi-
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            mo, commodiſſimòque modo deſignari poſſunt, aſſervatâ quam quis
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            adſignare voluerit proportione; </s>
            <s xml:id="echoid-s8574" xml:space="preserve">ſic ut inde cognitâ ſpatii repræſen-
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            tantis dimenſione, ſpatii per motum confecti quantitas faciliùs inno-
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            teſcat; </s>
            <s xml:id="echoid-s8575" xml:space="preserve">& </s>
            <s xml:id="echoid-s8576" xml:space="preserve">reciprocè, cognitâ ſpatii dicti naturâ velocitatis ac tem-
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            poris quantitatibus dignoſcendis aliqua lux aſſulgeat: </s>
            <s xml:id="echoid-s8577" xml:space="preserve">Quæ quidem
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            poſthac dicendorum intellectui neceſſaria, totíque motuum theoriæ
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            non parùm ut videtur utilia viſum eſt paullo fuſiùs expoſita præmittere.
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            </s>
            <s xml:id="echoid-s8578" xml:space="preserve">Quà perfunctus operâ pedem figo.</s>
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