Page:Popular Science Monthly Volume 43.djvu/746

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THE POPULAR SCIENCE MONTHLY.

low upward along the axis of the water jet, the lamps being placed in a chamber under the fountain provided with a transparent roof. Color effects are produced by the interposition of glass screens in the path of the beam. In the present fountains, which rise from basins sixty feet in diameter, the underground chamber is built upon piling, a construction rendered necessary by the shifting sand foundation. The piling is of unequal length, the shorter piles supporting the floor structure, and the longer, which project through and are seen as pillars in the room, the roof. The water nozzles are grouped to form nineteen composite jets, and as many powerful

PSM V43 D746 Electric fountains.jpg
Fig. 2.—Electric Fountains.

reflectors are arranged to throw a beam of light along the axis of each group. It is estimated that the beam of these powerful lights has a luminous intensity of two hundred and fifty thousand candles. The size of the fountains may be appreciated by the fact that they require a twenty-four-inch supply main con-