Merge pull request #13 from michael-77/master

Convert illustration to svg

src/epub/content.opf

@@ -78,14 +78,14 @@
 		<item href="css/core.css" id="core.css" media-type="text/css"/>
 		<item href="css/local.css" id="local.css" media-type="text/css"/>
 		<item href="images/cover.svg" id="cover.svg" media-type="image/svg+xml" properties="cover-image"/>
-		<item href="images/image151.png" id="image151.png" media-type="image/png"/>
+		<item href="images/image151.svg" id="image151.svg" media-type="image/svg+xml"/>
 		<item href="images/logo.svg" id="logo.svg" media-type="image/svg+xml"/>
 		<item href="images/titlepage.svg" id="titlepage.svg" media-type="image/svg+xml"/>
 		<item href="text/book-1.xhtml" id="book-1.xhtml" media-type="application/xhtml+xml"/>
 		<item href="text/book-2.xhtml" id="book-2.xhtml" media-type="application/xhtml+xml"/>
 		<item href="text/book-3.xhtml" id="book-3.xhtml" media-type="application/xhtml+xml"/>
 		<item href="text/book-4.xhtml" id="book-4.xhtml" media-type="application/xhtml+xml"/>
-		<item href="text/book-5.xhtml" id="book-5.xhtml" media-type="application/xhtml+xml"/>
+		<item href="text/book-5.xhtml" id="book-5.xhtml" media-type="application/xhtml+xml" properties="svg"/>
 		<item href="text/book-6.xhtml" id="book-6.xhtml" media-type="application/xhtml+xml"/>
 		<item href="text/book-7.xhtml" id="book-7.xhtml" media-type="application/xhtml+xml"/>
 		<item href="text/book-8.xhtml" id="book-8.xhtml" media-type="application/xhtml+xml"/>

src/epub/css/local.css

@@ -1,6 +1,11 @@
 @charset "utf-8";
 @namespace epub "http://www.idpf.org/2007/ops";
 
+[epub|type~="z3998:illustration"]{
+	display: block;
+	margin: auto;
+}
+
 [epub|type~="z3998:poem"] p{
 	text-align: left;
 	text-indent: 0;

src/epub/text/book-5.xhtml

@@ -96,7 +96,7 @@
 					<p>If you cut off a part from one of two equal lines and add it to the other, the second is now greater than the first by two such parts (for if you had only cut off the part from the first without adding it to the second, the second would have been greater by only one such part); the second exceeds the mean by one such part, and the mean also exceeds the first by one.</p>
 					<p>Thus we can tell how much to take away from him who has more or too much, and how much to add to him who has less or too little: to the latter’s portion must be added that by which it falls short of the mean, and from the former’s portion must be taken away that by which it exceeds the mean.</p>
 					<p>To illustrate this, let AA′, BB′, CC′ be three equal lines:⁠—</p>
-					<img alt="The first of three lines, A A′, is divided close to point A at point E. The second line is B B′, which is undivided. The third line, C C′, is extended past point C to point D by an amount equal to A E, and is divided between points C and C′ at point Z, which is as close to point C as E is to A." src="../images/image151.png" epub:type="z3998:illustration"/>
+					<img alt="The first of three lines, A A′, is divided close to point A at point E. The second line is B B′, which is undivided. The third line, C C′, is extended past point C to point D by an amount equal to A E, and is divided between points C and C′ at point Z, which is as close to point C as E is to A." src="../images/image151.svg" epub:type="z3998:illustration"/>
 					<p>From AA′ let AE be cut off; and let D [equal to AE] be added to CC′; then the whole DCC′ exceeds EA′ by CD and CZ [equal to AE or CD], and exceeds BB′ by CD.</p>
 					<p>And this<a href="../text/endnotes.xhtml#note-107" id="noteref-107" epub:type="noteref">107</a> holds good not only in geometry, but in the arts also; they could not exist unless that which is worked upon received an impression corresponding in kind and quantity and quality to the exertions of the artist.</p>
 					<p>But these terms, “loss” and “gain,” are borrowed from voluntary exchange. For in voluntary exchange having more than your own is called gaining, and having less than you started with is called losing (in buying and selling, I mean, and in the other transactions in which the law allows free play); but when the result to each is neither more nor less but the very same amount with which he started, then they say that they have their own, and are neither losers nor gainers. That which is just, then, is a mean between a gain and a loss, which are both contrary to the intention,<a href="../text/endnotes.xhtml#note-108" id="noteref-108" epub:type="noteref">108</a> and consists in having after the transaction the equivalent of that which you had before it.</p>