<p><a href="http://nemfrog.tumblr.com/post/102090136247/fig-121-the-elliptical-orbit-of-the-moon-allows" class="tumblr_blog">nemfrog</a>:</p>
<blockquote><p>Fig. 121. The elliptical orbit of the Moon allows a portion of its dark side to sometimes become visible.<b> Astronomy for the use of schools and academies. </b>1882.</p></blockquote>