All About Inventions and Discoveries
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Living on the Air 275 right angles the flame could be drawn, out so as to form a large roaring disc. As a result of this discovery Messrs. Birkeland and Eyde decided to build a furnace upon these lines with a view to determining its applicability to the production of atmospheric nitrates. The furnace re- presents a huge thin drum, built of steel and lined with fireclay. The electrodes are placed within, and it is found possible to obtain a flame about 6 feet in diameter. The air is driven into the burning space in a constant steady stream by means of a blower, and is compelled to traverse the flame so that it must be burned ; it is a reproduction of what occurs when a lightning discharge takes place. The first experimental furnace of 25 horse-power proving satisfactory, a larger furnace of 160 horse- power was constructed with which equally striking success was achieved. Thereupon the inventors estab- lished a small commercial plant of 660 horse-power, the results of which were so promising as to encour- age them to embark upon a more ambitious programme. A waterfall near Notodden, called the Tinnfoss, where some 2,400 horse-power was running to waste, was secured, and a plant capable of turning out about 5,000 tons of fertilising nitrates per annum when working at full pressure was laid down. But the demand for the product rose so rapidly, as it com- peted severely with the Chilian article, that the first works proved far too small. Within six months it became necessary to extend the plant sufficiently to enable an output of 50»000 tons per annum to be maintained. For this purpose another waterfall, the Svaelgos, above the Tinnfoss, was harnessed, and