produced from the term A to any other part of the oppo&longs;ite line
<lb/> C D.</s></p>
<p type="main"><s>SALV. </s><s>Your choice, and the rea&longs;on you bring for it in my judg­
<lb/> ment is mo&longs;t excellent; &longs;o that by this time we have proved that
<lb/> the fir&longs;t dimen&longs;ion is determined by a right line, the &longs;econd name­
<lb/> ly the breadth with another line right al&longs;o, and not onely right,
<lb/> but withall, at right-angles to the other that determineth the
<lb/> length, and thus we have the two dimen&longs;ions of length and
<lb/> breadth, definite and certain. </s><s>But were you to bound or termi­
<lb/> nate a height, as for example, how high this Roof is from the pave­
<lb/> ment, that we tread on, being that from any point in the Roof,
<lb/> we may draw infinite lines, both curved, and right, and all of di­
<lb/> ver&longs;e lengths to infinite points of the pavement, which of all the&longs;e
<lb/> lines would you make u&longs;e of?</s></p>
<p type="main"><s>SAGR. </s><s>I would fa&longs;ten a line to the Seeling, and with a plummet
<lb/> that &longs;hould hang at it, would let it freely di&longs;tend it &longs;elf till it
<lb/> &longs;hould reach well near to the pavement, and the length of &longs;uch a
<lb/> thread being the &longs;treighte&longs;t and &longs;horte&longs;t of all the lines, that could
<lb/> po&longs;sibly be drawn from the &longs;ame point to the pavement, I would
<lb/> &longs;ay was the true height of this Room.</s></p>
<p type="main"><s>SALV. </s><s>Very well, And when from the point noted in the pave­
<lb/> ment by this pendent thread (taking the pavement to be levell
<lb/> and not declining) you &longs;hould produce two other right lines, one
<lb/> for the length, and the other for the breadth of the &longs;uperficies of
<lb/> the&longs;aid pavement, what angles &longs;hould they make with the &longs;aid
<lb/> thread?</s></p>
<p type="main"><s>SAGR. </s><s>They would doubtle&longs;s meet at right angles, the &longs;aid
<lb/> lines falling perpendicular, and the pavement being very plain and
<lb/> levell.</s></p>
<p type="main"><s>SALV. </s><s>Therefore if you a&longs;&longs;ign any point, for the term from whence
<lb/> to begin your mea&longs;ure; and from thence do draw a right line, as
<lb/> the terminator of the fir&longs;t mea&longs;ure, namely of the length, it will
<lb/> follow of nece&longs;&longs;ity, that that which is to de&longs;ign out the largene&longs;s
<lb/> or breadth, toucheth the fir&longs;t at right-angles, and that that which is
<lb/> to denote the altitude, which is the third dimen&longs;ion, going from the
<lb/> &longs;ame point formeth al&longs;o with the other two, not oblique but right
<lb/> angles, and thus by the three perpendiculars, as by three lines, one,
<lb/> certain, and as &longs;hort as is po&longs;&longs;ible, you have the three dimen&longs;ions
<lb/> A B length, A C breadth, and A D height; and becau&longs;e, clear it
<lb/> is, that there cannot concurre any more lines in the &longs;aid point, &longs;o
<lb/> as to make therewith right-angles, and the dimen&longs;ions ought to
<lb/> be determined by the &longs;ole right lines, which make between them­
<lb/> &longs;elves right-angles; therefore the dimen&longs;ions are no more but
<lb/> three, and that which hath three hath all, and that which hath all,
<lb/> is divi&longs;ible on all &longs;ides, and that which is &longs;o, is perfect, <emph type="italics"/>&c.<emph.end type="italics"/></s></p>
