Niagara's Drying Up.

Progress, Volume I, Issue 5, 1 March 1906, Page 113

Niagara's Drying Up.

As to the possibility of the destruction of Niagara Falls, a lecturer stated that in, 1885 Mr. Evershed thought he was taking a very safe line in saying that for power purposes no more than 4 per cent, would be required. If 150,000 h.p. were produced, the daily demand would be 1 r.ooo cubic feet per second, which was 5 per cent, of the mean flow, or not 7 per cent, of the minimum now. The development of 650,000 h.p. demanded 48,000 cubic feet per second, or 2i£ per cent, of the mean flow and 30 per cent, of the minimum flow. It was obvious that when the whole of the machinery was in working order the alteration in the appearance of the falls would be striking. Taking into account the water used for the Welland Canal and Chicago drainage and other canals projected, the total diversion of water would be at least 41 per cent, of the minimum flow. Nor was the end of projects for the diversion yet in sight, so that there seemed likely to be a fulfilment of Lord Kelvin's prophecy that before long. Niagara would be a dry ravine.

A wind pressure indicator for railway use has been introduced. The event leading to its invention occurred during a gale in February, 1903, when a train was blown over on Levens Viaduct, on the Furness line, England. Now there is an instrument which will automatically warn the signalmen on duty at Cark and Plumpton when there is a wind pressure of sufficient force to be dangerous. The indicator consists of a combined wind-pressure gauge and recorder, and is connected with an electric arrangement, by means of which bells are set in motion at distant signal cabins. These bells will continue to ring as long as the velocity of the wind on the viaduct is dangerous to passing trains.

The Stolze gas turbine was invented by Dr. Stolze as far back as 1873, an( 3 the principal underlying its construction consists in compressing atmospheric air to, say, one and one-half atmospheres above atmospheric pressure, and in heating this compressed air so as to cause it to assume a two or two-and-one-half fold volume, with the same tension, after which the air tension is allowed .to drop again to atmospheric pressure. The excess of work performed over the absorbed energy is thus due to the increase in volume resulting from the heating. Two sets of turbines of different designs are mounted on a common shaft. One of these serves as an air compresser, while the other drives the shaft by means of the heated air. Each set consists of several rows of guiding vanes, fitted to the engine casing, and of several rows of running vanes of a corresponding design, secured to a common rotating cone, which turns with the shaft. One of these turbine systems draws in the fresh air, compresses it to a given tension through a pre-heater (heated with exhaust gases), and drives the greater part of it into a chamber lined with refractory material. The smaller is conveyed beneath the grate of a producer, where it serves to volatilise the fuel. The gas thus formed penetrates into the chamber mentioned, to be burnt there by the compressed air in suitable burners and converted into carbonic acid and water vapour, while evolving large amounts of heat. These gases next enter the second turbine system, where they are allowed to expand in traversing the various steps, thus performing useful work. The process is thus analogous to the cycle performed in all internal combustion engines. A distinguishing feature is, however, that the mixing takes place after compressing.