Initial from a 1551 architectural treatise
<span lang="en">Anonymous</span><span style="display:none">Unknown author</span>
<i>Extraordinario libro di architettura di Sebastiano Serlio</i> (<a rel="nofollow" class="external free" href="https://archive.org/details/ldpd_12223091_000/page/n5/mode/2up">https://archive.org/details/ldpd_12223091_000/page/n5/mode/2up</a>)