STEPS OF URRBINO.
The plinth must be as broad as the thickness of the wall against which the plinth is built. [Footnote: See Pl. CX No. 3. The hasty sketch on the right hand side illustrates the unsatisfactory effect produced when the plinth is narrower than the wall.]
Taken from The Notebooks of Leonardo da Vinci edited by Jean Paul Richter, 1880.