IV.
Perspective of Disappearance
Definition (222. 223).—An illustration by experiment (224).—A guiding rule (225).—-An experiment (226).—On indistinctness at short distances (227—231).—On indistinctness at great distances (232—234).—The importance of light and shade in the Prospettiva de' perdimenti (235—239).—The effect of light or dark backgrounds on the apparent size of objects (240—250).—Propositions on Prospettiva de' perdimenti from MS. C. (250—262).