"A complete study of the gas engine problem would involve consideration of the two general classes of motors operated by the expansive energy of combustible gases, namely - piston engines with reciprocating action, and turbine engines with rotary motion." Воспроизведено в оригинальной авторской орфографии (издательство "Theo. Audel & Co. publishers"). Это и многое другое вы найдете в книге Gas Engine Manual