The Combustion Gas Turbine.--DR. J. T. RETALIATA in Bulletin No. 4 of the Allis-Chalmers Manufacturing Company, Milwaukee, Wisconsin, deals with the development and theory of the gas turbine, as well as the features which make it appear as possessing attractive potentialities for certain classes of service. At the present time the continuous combustion gas turbine development is being carefully investigated by Allis-Chalmers. Five gas turbineaxial compressor units have been constructed to the designs of Brown-Boveri. Field experience with these machines should provide basic data for the future application of this power cycle. The advantages associated with the elimination of the high pressure, high temperature steam boiler and the attendant feedwater problems from a power plant are obvious. There is on the other hand a lack of experience with certain features of the development and further experience is necessary in connection with the effect of high oxygen content gas on blading materials at temperatures around IOOO ยฐ F. and other matters. There is also the problem of reliable control of the combustion to prevent gas of excessive temperature reaching the turbine blading. The destiny of the steam turbine is not being decided by the gas turbine nor is its future even slightly jeopardized. The gas turbine must develop approximately four times as much energy as that which it delivers as excess, so its bid as a serious competitor to large steam turbines would require consi'derable development due to physical limitations. In moderate sizes, however, it will become an aspirant in the power field when higher operating temperatures are permitted by improved methods of blade cooling and materials with better creep and other high temperature properties. R. H. O.