Caverni, Raffaello, Storia del metodo sperimentale in Italia, 1891-1900

Table of figures

< >
[Figure 731]
Page: 2732
[Figure 732]
Page: 2733
[Figure 733]
Page: 2734
[Figure 734]
Page: 2736
[Figure 735]
Page: 2737
[Figure 736]
Page: 2738
[Figure 737]
Page: 2739
[Figure 738]
Page: 2744
[Figure 739]
Page: 2745
[Figure 740]
Page: 2745
[Figure 741]
Page: 2752
[Figure 742]
Page: 2753
[Figure 743]
Page: 2753
[Figure 744]
Page: 2754
[Figure 745]
Page: 2755
[Figure 746]
Page: 2755
[Figure 747]
Page: 2756
[Figure 748]
Page: 2756
[Figure 749]
Page: 2756
[Figure 750]
Page: 2757
[Figure 751]
Page: 2758
[Figure 752]
Page: 2759
[Figure 753]
Page: 2759
[Figure 754]
Page: 2760
[Figure 755]
Page: 2762
[Figure 756]
Page: 2762
[Figure 757]
Page: 2763
[Figure 758]
Page: 2763
[Figure 759]
Page: 2765
[Figure 760]
Page: 2765
< >
page |< < of 3504 > >|
    <archimedes>
      <text>
        <body>
          <chap>
            <p type="main">
              <s>
                <pb xlink:href="020/01/701.jpg" pagenum="144"/>
              sia piena d'acqua, fino al giro H (fig. </s>
              <s>46). Poi sotto questa caraffa, nel
                <lb/>
              luogo EF, pongasi del fuoco molto lento: si vedrà a poco a poco crescer
                <lb/>
              l'acqua fino in G, e nel fondo della caraffa si vedranno alcuni campanelletti,
                <lb/>
              li quali di quando in quando partendosi dal fondo ascenderanno per l'acqua
                <lb/>
              fino alla sommità del suo livello in G, dove rompendosi si risolveranno.
                <lb/>
                <figure id="id.020.01.701.1.jpg" xlink:href="020/01/701/1.jpg" number="111"/>
              </s>
            </p>
            <p type="caption">
              <s>Figura 46.
                <lb/>
              Fredda che sarà la medesima acqua, si vedrà tornare al suo primo
                <lb/>
              livello in H, e non esser punto scemata, ma noi per l'addotta
                <lb/>
              esperienza ricerchiamo fuoco lento come s'è detto. </s>
              <s>” </s>
            </p>
            <p type="main">
              <s>“ Si potrà dunque adesso domandare che cosa sia stato
                <lb/>
              ch'abbia dato causa al crescer di quell'acqua. </s>
              <s>So che mi po­
                <lb/>
              trebb'esser risposto che, avendo il fuoco virtù di rarefare, abbia
                <lb/>
              rarefatto quell'acqua. </s>
              <s>Ma io domando che cosa fosse in que'cam­
                <lb/>
              panelli che, spinti di quando in quando all'in su, svaporano. </s>
              <s>Io
                <lb/>
              veramente non so qual risposta mi potrebbe esser data, ma sento
                <lb/>
              bene astringermi a confessare esser quelli diversi aggregati di
                <lb/>
              corpuscoli ignei, che sormontando per l'acqua, come leggeris­
                <lb/>
              simi, svaporassero. </s>
              <s>Quindi è ch'essendone ancora gran quantità
                <lb/>
              mescolata nell'acqua, la fanno crescere in mole; onde partendosi essi torna
                <lb/>
              essa allo stato di prima, il che parmi che apertamente dimostri questo che
                <lb/>
              noi chiamiamo calore prodursi per mezzo di questi tali corpuscoli ” (MSS.
                <lb/>
              Gal. </s>
              <s>Disc., T. CXXXIV, c. </s>
              <s>22). </s>
            </p>
            <p type="main">
              <s>Benchè così fatte dottrine che si derivarono dagli Antichi fossero, come
                <lb/>
              vedemmo, sanzionate dall'autorità di Galileo, così potente sull'animo e sul­
                <lb/>
              l'ingegno de'nostri Accademici, sorse, per amor del vero, alcuno in mezzo
                <lb/>
              di essi che, se non ebbe la perspicacia di riconoscervi il falso, ebbe nono­
                <lb/>
              stante la franchezza di mettervi il dubbio. </s>
            </p>
            <p type="main">
              <s>“ Fu addotta però, soggiunge il Viviani, in confutazione di simil parere
                <lb/>
              un'altra esattissima prova dal signor dottor Rinaldini, la quale è che, se
                <lb/>
              noi piglieremo due palle di egual grandezza, l'una d'ebano legno durissimo,
                <lb/>
              l'altra di sughero, e poste tutt'e due in egual distanza dal fuoco e tenute
                <lb/>
              per qualche tempo, levate che saranno le dette palle si troverà molto più
                <lb/>
              calda quella di ebano che quella di sughero. </s>
              <s>Di qui pareva di potersi pro­
                <lb/>
              durre il calore non altrimenti potersi generare per via di questi corpuscoli,
                <lb/>
              poichè, essendo il legno del sughero molto poroso, e per conseguenza più
                <lb/>
              atto a ricevere i medesimi corpuscoli, doveva trovarsi più caldo dell'ebano
                <lb/>
              assai più nelle sue parti costipato. </s>
              <s>Eppure per l'esperienza tutto il contra­
                <lb/>
              rio succede: adunque par forza confessare il calore non prodursi in tal ma­
                <lb/>
              niera ” (ivi). </s>
            </p>
            <p type="main">
              <s>Avrebbe potuto rispondere il Viviani che la superficie nera dell'ebano
                <lb/>
              tiene, come il Castelli s'immaginava, così disposti i suoi pori da introdurvi
                <lb/>
              più gran numero d'ignicoli di quel che la superficie del sughero non fac­
                <lb/>
              cia, ma egli così cerca più sottili argomenti alla sua risposta, ricorrendo alla
                <lb/>
              varia capacità del calore, secondo la varia costituzione de'corpi. </s>
            </p>
            <p type="main">
              <s>“ L'esperienza veramente, prima per essere stata addotta da eccellen-</s>
            </p>
          </chap>
        </body>
      </text>
    </archimedes>
Impressum