Salusbury, Thomas, Mathematical collections and translations (Tome I), 1667
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              ficies of an oblique Cylinder, which hath for one of its baſes
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              the ſaid annual circle, and for the other a like circle
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              rily deſcribed by its extremity, or, (if you will) Pole, amongſt
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              the fixed ſtars. </s>
              <s>And this ſame cylinder is oblique to the Plane of
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              the Ecliptick, according to the inclination of the Axis that
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              ſcribeth it, which we have ſaid to be 23 degrees and an half,
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              the which continuing perpetually the ſame (ſave onely, that in
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              many thouſands of years it maketh ſome very ſmall mutation,
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              which nothing importeth in our preſent buſineſſe) cauſeth that
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              the Terreſtrial Globe doth never more incline or elevate, but
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              ſtill conſerveth the ſame ſtate without mutation. </s>
              <s>From whence
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              enſueth, that as to what pertaineth to the mutations to be
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              ſerved in the fixed ſtars dependant on the ſole annual motion,
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              the ſame ſhall happen to any point whatſoever of the Earths
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              ſurface, as befalleth unto the centre of the Earth it ſelf; and
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              therefore in the preſent explanations we will make uſe of the
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              centre, as if it were any whatſoever point of the ſuperficies.
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              <s>And for a more facile underſtanding of the whole, let us deſign
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              the ſame in lineal figures: And firſt of all let us deſcribe in the
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              Plane of the Ecliptick the circle A N B O [
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              in Fig.
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              7.] and let
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              us underſtand the points A and B, to be the extreams towards
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              the North and South; that is, the beginning of [
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              or entrance into
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              ]
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              Cancer
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              or
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              Capricorn,
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              and let us prolong the Diameter A B,
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              determinately by D and C towards the Starry Sphere. </s>
              <s>I ſay
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              now in the firſt place, that none of the fixed ſtars placed in the
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              Ecliptick, ſhall ever vary elevation, by reaſon of any
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              ever mutation made by the Earth along the ſaid Plane of the
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              Ecliptick, but ſhall alwayes appear in the ſame ſuperficies,
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              though the Earth ſhall approach and recede as great a ſpace as is
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              that of the diameter of the Grand Orb, as may plainly be
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              ſeen in the ſaid figure. </s>
              <s>For whether the Earth be in the point
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              A or in B, the ſtar C alwayes appeareth in the ſame line A B C;
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              although the diſtance B C, be leſſe than A C, by the whole
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              diameter A B. </s>
              <s>The moſt therefore that can be diſcovered in the
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              ſtar C, and in any other placed in the Ecliptick, is the
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              mented or diminiſhed apparent magnitude, by reaſon of the
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              proximation or receſſion of the Earth.</s>
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            <p type="margin">
              <s>
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              The annual
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              tion made by the
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              centre of the Earth
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              under the
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              tick and the
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              nal motion made
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              by the Earth about
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              its own centre.
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              </s>
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            <p type="margin">
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              The axis of the
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              Earth continueth
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              alwayes parallel to
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              it ſelf, and
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              beth a
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              cal ſuperficies,
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              clining to the
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              grand Orb.
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              </s>
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            <p type="margin">
              <s>
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              The Orb of the
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              Earth never
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              neth, but is
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              mutably the ſame.
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              The fixed ſtars
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              placed in the
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              cliptick never
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              vate nor deſcend,
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              on account of the
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              annual motion, but
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              yet approach and
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              recede.
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              </s>
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              <s>SAGR. </s>
              <s>Stay a while I pray you, for I meet with a certain
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              ſcruple, which much troubleth me, and it is this: That the ſtar
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              C may be ſeen by the ſame line A B C, as wel when the Earth
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              is in A, as when it is in B, I underſtand very well, as alſo
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              thermore I apprehend that the ſame would happen in all the
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              points of the line A B, ſo long as the Earth ſhould paſſe from A
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              to B by the ſaid line; but it paſſing thither, as is to be ſuppoſed,
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              by the arch A N B, it is manifeſt that when it ſhall be in the </s>
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