Vitruvius
<p ><b>Marcus Vitruvius Pollio</b> (born c. 80–70 BC, died after c. 15 BC) was a <a href="http://en.wikipedia.org/wiki/Latin_literature" title="Latin literature" >Roman writer</a>, architect and engineer, active in the 1st century BC. He is best known as the author of the multi-volume work <i><a href="http://en.wikipedia.org/wiki/De_Architectura" title="De Architectura" class="mw-redirect" >De Architectura</a></i> ("On Architecture").
By his own description<sup id="cite_ref-autogenerated1_0-0" class="reference" ><a href="http://en.wikipedia.org/wiki/Vitruvius#cite_note-autogenerated1-0" >[1]</a></sup> Vitruvius served as a <a href="http://en.wikipedia.org/wiki/Ballista" title="Ballista" >ballista</a> (artilleryman), the third class of arms in the military offices. He likely served as chief of the ballista (senior officer of artillery) in charge of <i>doctores ballistarum</i> (artillery experts) and <i>libratore</i>s who actually operated the machines.<sup id="cite_ref-1" class="reference" ><a href="http://en.wikipedia.org/wiki/Vitruvius#cite_note-1" >[2]</a></sup></p>
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<img src="/3a201dad-58e1-5447-9d65-34e42362834e.jpg"/></p>
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<i ><a href="http://en.wikipedia.org/wiki/Vitruvian_Man" title="Vitruvian Man" >Vitruvian Man</a></i> by <a href="http://en.wikipedia.org/wiki/Leonardo_da_Vinci" title="Leonardo da Vinci" >Leonardo da Vinci</a>, an illustration of the human body inscribed in the circle and the square derived from a passage about geometry and human proportions in Vitruvius's writings</p>