1555. The field of vision, or portion of landscape which the eye will comprehend, is a circumstance frequently mistaken in fixing a situation for a house; since a view seen from the windows of an apartment will materially differ from the same view seen in the open air. Much evidently depends on the thickness of the walls (fig. 267.), the width of the windows (a), and the distance of the spectator from the aperture. Near the centre of the room (b), the spectator will not enjoy above 20 or 30 degrees of vision; but close to the window (c) his eye will take in from 70 to 100 degrees. Hence, to obtain as much of the view from a room as possible, there should not only be windows on two sides of a room, but one in the angle, or an oblique or bow-window on each side, instead of the common form. (Obs, on Landscape-Gardening, p. 24.)
