(2). Paper mills, Jute mills, Textile mills.
(3). Screw propellers for marine propulsion.
The development by Parsons in 1910 of the small double-helical speed-reducing gears of de Laval, so as to be suitable for trans mitting large powers, has permitted complete freedom of choice with regard to speeds, so that the steam turbine can now be applied to the driving of anything in which continuous rotary motion is required. The design of the earlier marine installations was largely a matter of compromise between the high speed of revolution required for the turbine and the much lower speed which was more suitable for the propeller. Since the introduction of mechanical gearing, the marine turbine has tended to become assimilated in type to the land turbine, the same conditions for high thermal efficiency, namely, high velocity ratios, high steam pressures and temperatures, and lowest possible exhaust steam pressures being equally applicable.
Howard Lectures, Jrnl., Roy. Soc. of Arts (1923).
For those readers who desire to study the subject more closely the following papers are recommended:—K. Baumann, "Recent Steam Turbine Practice" and "Some Recent Developments in Large Steam Turbines," Jrnl. Inst. Elec. Engineers, 1912, Vol. 48, p. 768 and Vol. 59, p. 565 ; Hon. C. A. Parsons, C.B., F.R.S. and G. Gerald Stoney, B.A., "The Steam Turbine," Proc. Inst. Civil Engineers (1906) ; Hon. Sir C. A. Parsons, K.C.B., etc., "Steam Turbines," Trans. 1st World Power Conference, 1924. Vol. 2, page 1477 ; Hon. Sir C. A. Parsons, K.C.B., etc., R. J. Walker, C.B.E., and S. S. Cook, B.A., "Progress in Economy of Turbine Machinery on Land and Sea," Tram. N.E. Coast Inst. of Engineers & Shipbuilders, Newcastle-on-Tyne, Jan. 1927; H. L. Guy, "The Economic Value of Increased Steam Pressure," Proc. Inst. Mech. Engineers, 1927, No. 1; A. H. Law and J. P. Chittenden, "Higher Steam Pressures and Their Application," Jrnl. Inst. Elec. Eng., Vol. 66, No. 373, p. 89.
The following textbooks are standard works on the theory of steam turbine design and construction:—Prof. W. J. Goudie, D.Sc., Steam Turbines, 2nd ed. (1922) ; Prof. A. Stodola, Steam and Gas Turbines 2 Vols., Eng. trans. by Louis Lowenstein from 6th German ed. (1927).
(R. Do.)