All About Engines

I7° All About Engines wheels or rings of blades. During the next four years—up to the end of 1888—a number of similar turbines were built, but none of them was of larger size than 150 horse-power. In 1889 the Heaton works of C. A. Parsons and Co. were founded in order to allow of more and larger turbines being built under the direct supervision of the inventor. Unfortunately, at this point there were legal troubles in regard to the validity of the patents, and Sir Charles Parsons was not permitted to manufacture his parallel-flow turbine until 1894. Thus while 60,000 horse-power had been constructed by 1889, the horse-power produced between that year and 1894 was only 10,000. From 1894, however, the inventor came into his own. Nearly every year saw an increase in the power of individual machines and an increase in their economy of working. The 150-horse-power turbines to which reference has been made were constructed in 1886, and ran at 4,800 revolutions per minute. The first turbine over 150 horse-power was made in 1891, and the first over 200 horse-power in 1892. By 1894 500-, by 1899 1,500-, by 1906 6,000-, by 1908 io,ooo-horse-power turbines were at work. The earlier turbines were non-condensing, and took about 20 lb. of steam per horse-power per hour ; the later ones, fitted with the most effective air pumps and condensers, required only about 9 lb. The general construction of the Parsons Turbine will be understood from the section given in Fig. 102 on Plate 12. Steam enters by the two channels, aa, shown