I never tire of discovering polymathic figures from the past, who make the multiskilling of today seem rather tame. Vitruvius, who lived during the first century B.C. is another of those who appears to have had gifts in a range of disciplines.
De Architectura (now referred to as The Ten Books of Architecture) was the first known treatise on the subject and in it Vitruvius displays talent in engineering, art as well of course as extensive architectural understanding. His account of human proportions in Book III inspired the very famous drawing above by Da Vinci. Vitruvius was an architect himself but the single construction definitely attributable to him has long since disappeared.
One famous quote (which could itself be a misquote from translation from latin in the 16th century) is - "Well building hath three conditions: firmness, commodity, and delight."
The history of the written text and many illustrations he drafted is very convoluted. There have been translation problems at the very minimum and if I understood correctly, the illustrations posted here are among a set sketched during the renaissance as faithful renditions from the original text.
Bill Thayer's University of Chicago website would appear to be the best resource on textual fidelity on the web. Clicking on the roman numerals
There are 11 pages of scanned illustration thumbnails (fast loading) at the Australian National University website.
Wikipedia on De Architectura.