The water should be allowed to fall from the whole circle _a b_.
[Footnote: Other drawings of fountains are given on Pl. CI (W. XX);
the original is a pen and ink drawing on blue paper; on Pl. CIII
(MS. B.) and Pl. LXXXII.]

_VI. Studies of architectural details._

_Several of Leonardo's drawings of architectural details prove that,
like other great masters of that period, he had devoted his
attention to the study of the proportion of such details. As every
organic being in nature has its law of construction and growth,
these masters endeavoured, each in his way, to discover and prove a
law of proportion in architecture. The following notes in Leonardo's
manuscripts refer to this subject._

_MS. S. K. M. Ill, 47b (see Fig. 1). A diagram, indicating the rules
as given by Vitruvius and by Leon Battista Alberti for the
proportions of the Attic base of a column._

_MS. S. K. M. Ill 55a (see Fig. 2). Diagram showing the same rules._