Salusbury, Thomas, Mathematical collections and translations (Tome I), 1667

Table of figures

< >
[Figure 311]
Page: 1139
[Figure 312]
Page: 1140
[Figure 313]
Page: 1143
[Figure 314]
Page: 1144
[Figure 315]
Page: 1146
[Figure 316]
Page: 1146
[Figure 317]
Page: 1148
[Figure 318]
Page: 1149
[Figure 319]
Page: 1150
[Figure 320]
Page: 1168
[Figure 321]
Page: 1170
[Figure 322]
Page: 1173
[Figure 323]
Page: 1177
[Figure 324]
Page: 1179
[Figure 325]
Page: 1180
[Figure 326]
Page: 1181
[Figure 327]
Page: 1183
[Figure 328]
Page: 1189
[Figure 329]
Page: 1192
[Figure 330]
Page: 1195
[Figure 331]
Page: 1201
< >
page |< < of 701 > >|
    <archimedes>
      <text>
        <body>
          <chap>
            <p type="main">
              <s>
                <pb xlink:href="040/01/377.jpg" pagenum="357"/>
              deſcribed within the ſame, and neerer to the pole A, ſhall wholly
                <lb/>
              be included in the illuminated part; as on the contrary, the
                <lb/>
              poſite ones towards the Pole B, contained within the
                <lb/>
              lel L M, ſhall remain in the dark. </s>
              <s>Moreover, the arch A I
                <lb/>
              ing equal to the arch F D, and the arch A F, common to them
                <lb/>
              both, the two arches I K F and A F D ſhall be equal, and each
                <lb/>
              a quadrant or 90 degrees. </s>
              <s>And becauſe the whole arch I F M
                <lb/>
              is a ſemicircle, the arch F M ſhall be a quadrant, and equal to
                <lb/>
              the other F K I; and therefore the Sun O ſhall be in this ſtate
                <lb/>
              of the Earth vertical to one that ſtands in the point F. </s>
              <s>But by
                <lb/>
              the revolution diurnal about the ſtanding Axis A B, all the points
                <lb/>
              of the parallel E F paſſe by the ſame point F: and therefore in
                <lb/>
              that ſame day the Sun, at noon, ſhall be vertical to all the
                <lb/>
              bitants of the Parallel E F, and will ſeem to them to deſcribe in its
                <lb/>
              apparent motion the circle which we call the Tropick of Cancer.
                <lb/>
              </s>
              <s>But to the inhabitants of all the Parallels that are above the
                <lb/>
              rallel E F, towards the North pole A, the Sun declineth from
                <lb/>
              their
                <emph type="italics"/>
              Vertex
                <emph.end type="italics"/>
              or Zenith towards the South; and on the contrary,
                <lb/>
              to all the inhabitants of the Parallels that are beneath E F,
                <lb/>
              wards the Equinoctial C D, and the South Pole B, the Meridian
                <lb/>
              Sun is elevated beyond their
                <emph type="italics"/>
              Vertex
                <emph.end type="italics"/>
              towards the North Pole A.
                <lb/>
              Next, it is viſible that of all the Parallels, only the greateſt C D
                <lb/>
              is cut in equal parts by the Terminator of the light I M. </s>
              <s>But
                <lb/>
              the reſt, that are beneath and above the ſaid grand circle, are all
                <lb/>
              interſected in parts unequal: and of the ſuperiour ones, the
                <lb/>
              midiurnal arches, namely thoſe of the part of the Terreſtrial
                <lb/>
              face, illuſtrated by the Sun, are bigger than the ſeminocturnal
                <lb/>
              ones that remain in the dark: and the contrary befalls in the
                <lb/>
              remainder, that are under the great one C D, towards the pole B,
                <lb/>
              of which the ſemidiurnal arches are leſſer than the ſeminocturnal,
                <lb/>
              It is likewiſe apparently manifeſt, that the differences of the ſaid
                <lb/>
              arches go augmenting, according as the Parallels are neerer to
                <lb/>
              the Poles, till ſuch time as the parallel I K comes to be wholly in
                <lb/>
              the part illuminated, and the inhabitants thereof have a day of
                <lb/>
              twenty four hours long, without any night; and on the contrary,
                <lb/>
              the Parallel L M, remaining all in obſcurity, hath a night of
                <lb/>
              twenty four hours, without any day. </s>
              <s>Come we next to the
                <lb/>
              third Figure of the Earth, placed with its centre in the point
                <lb/>
              Cancer, where the Sun ſeemeth to be in the firſt point of
                <lb/>
              pricorn. </s>
              <s>We have already ſeen very manifeſtly, that by reaſon
                <lb/>
              the Axis A B doth not change inclination, but continueth
                <lb/>
              lel to it ſelf, the aſpect and ſituation of the Earth is the ſame to
                <lb/>
              an hair with that in the firſt Figure; ſave onely that that
                <lb/>
              ſphere which in the firſt was illuminated by the Sun, in this
                <lb/>
              maineth obtenebrated, and that cometh to be luminous, which in </s>
            </p>
          </chap>
        </body>
      </text>
    </archimedes>
Impressum