I346

That Part of a Building, which is found in the grossest Air, will be the least sensible, and will show it self the least; and on the contrary, that Part found in the purest Air, will appear the most visible and distinct: Thus, if you suppose the Eye N, looking at the Tower A D, every Part will be seen the more confusedly, in proportion as it approaches nearer the Earth; and more clearly and distinctly, as it is further removed from it.