15. There are six candles on the board of the Automaton during exhibition. The question naturally arises—“Why are so many employed, when a single candle, or, at farthest, two, would have been amply sufficient to afford the spectators a clear view of the board, in a room otherwise so well lit up as the exhibition room always is—when, moreover, if we suppose the machine a _pure machine, _there can be no necessity for so much light, or indeed any light at all, to enable _it _to perform its operations—and when, especially, only a single candle is placed upon the table of the antagonist?” The first and most obvious inference is, that so strong a light is requisite to enable the man within to see through the transparent material (probably fine gauze) of which the breast of the Turk is composed. But when we consider the arrangement of the candles, another reason immediately presents itself. There are six lights (as we have said before) in all. Three of these are on each side of the figure. Those most remote from the spectators are the longest—those in the middle are about two inches shorter—and those nearest the company about two inches shorter still—and the candles on one side differ in height from the candles respectively opposite on the other, by a ratio different from two inches—that is to say, the longest candle on one side is about three inches shorter than the longest candle on the other, and so on. Thus it will be seen that no two of the candles are of the same height, and thus also the difficulty of ascertaining the _material _of the breast of the figure (against which the light is especially directed) is greatly augmented by the dazzling effect of the complicated crossings of the rays—crossings which are brought about by placing the centres of radiation all upon different levels.