been obtained by the investigation of buildings which were 
in existence at Rome during his age: but, on the contrary, 
to have been collected from writings, on that science, left by 
his predecessors. Of those which he enumerates, it appears 
that three only were productions of his countrymen. With 
the exception of a volume written by Fussitius, and two small 
tracts, one by Varro, and another by Publius Septimus, no 
work upon the science of architecture seems to have been 
known to our author. On the other hand, he confesses to 
have derived the greatest assistance from the writings ot 
Grecian architects upon that subject. These he states to 
have been numerous, and acknowledges that they supplied 
him with the principal materials in the formation of his 
treatise. Hence it will not be thought extraordinary, that 
the various proportions he assigns to the different orders 
should correspond very nearly with those adopted in Grecian 
buildings: more particularly in the Ionic, upon which order 
the number of writings enumerated by him greatly exceeded 
the works upon the two remaining. 
Opportunities are afforded to us of ascertaining the extent 
of his plagiarism, by the partial existence of monuments, the 
subjects of the very works whence he admits that he derived 
his knowledge of architectural proportions. Amongst these 
may be mentioned the temple of Minerva Polias and the 
Erectheum, upon the acropolis of Athens; the temple of 
Minerva, at Priene, and that of Bacchus at Teos. In 
investigating, therefore, his proportions for the Ionic order. 
we shall compare them with those which have been adopted 
in these buildings.