INTERCOLUMNIATION  , in

architecture, the distance between the columns of a peristyle, generally referred to in terms of the lower diameter of the column . They are thus set forth by Vitruvius (iii . 2): (a) Pycnostyle, equal to 12 diameters; (b) Systyle, 2 diameters; (c) Eustyle, 24 diameters (which was the proportion' preferred by him); (d) Diastyle, 3 diameters; and (e) Araeostyle or wide spaced, 4" diameters, a span only= possible when the architrave was in wood . Vitruvius's definition would seem to apply only to examples with which he was acquainted in Rome, or to Greek temples described by authors he had studied . In the earlier Doric temples the intercolumniation is sometimes less than one diameter, and it increases gradually as the style developed; thus in the Parthenon it is 1;, in the Temple of Diana Propylaea at Eleusis, 11; and in the portico at Delos, 22 . The intercolumniations of the columns of the Ionic Order are greater, averaging 2 diameters, but then the relative proportion of height to diameter in the column has to be taken into account, as also the width of the peristyle . Thus in the temple of Apollo Branchidae, where the columns are slender and over to diameters in height, the intercolumniation is 11, notwithstanding its late date, and in the Temple of Apollo Smintheus in Asia Minor, in which the peristyle is pseudodipteral, or double width, the intercolumniation is just over 11 . Temples of the Corinthian Order follow the proportions of those of the Ionic Order .