78 THE STONES OF VENICE

shape of the entire aperture; secondly, the way in which it is to be filled with valves or glass; and, thirdly, the modes of protecting it on the outside, and fitting appliances of convenience to it, as porches or balconies. And this will be our division F; and if the reader will have the patience to go through these six heads, which include every possible feature of protective architecture, and to consider the simple necessities and fitnesses of each, I will answer for it, he shall never confound good architecture with bad any more. For, as to architecture of position, a great part of it involves necessities of construction with which the spectator cannot become generally acquainted, and of the compliance with which he is therefore never expected to judge,-as in chimneys, light-houses, etc.: and the other forms of it are so closely connected with those of protective architecture, that a few words in Chap. XIX. respecting staircases and towers will contain all with which the reader need be troubled on the subject.

[Version 0.04: March 2008]