In this figure <em>BB</em> is the base line; <em>HH</em> the common horizontal or vanishing line; <em>C</em> the centre of view in that vanishing linel <em>LL</em> the vanishing line of the ascent; and <em>C1</em> the centre of view in that vanishing line.

Horizontal Line Diagram

In this figure BB is the base line; HH the common horizontal or vanishing line; C