256 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1962 



Curtiss's earliest engines were air-cooled, including the V-8 engine 

 used in the famous June Bug (pi. 8, fig. 1) . However, by 1908 he had 

 settled on an 8-cylinder water-cooled Vee engine, similar to the "An- 

 toinette" of Lavavasseur except that the cylinders were of cast iron, 

 with monel-metal water jackets. 



After the Wright brothers, Glenn Curtiss was certainly the most 

 important figure in early American aviation, both in engine design 

 and airplane design. The most noteworthy engine which developed 

 from his early work was the famous "OX-5," to be described later. 

 Engines bearing his name have an important place in aviation to this 

 day. 



The year 1909 has been called the "year of practical powered flying," 

 because in that year flight began to be convincingly demonstrated by 

 other than the Wright brothers. Four types of airplane — Wright, 

 Antoinette, Farman, and Bleriot — demonstrated flights of more than 

 1 hour duration. 



Bleriot made his famous cross-channel flight (37 minutes, 23.5 

 miles) on July 25, 1909. His tractor monoplane was equipped with 

 the 25-hp. 3-cylinder Anzani, fan-type air-cooled engine (pi. 7, fig. 2). 

 Later Anzani built one- and two-row radial air-cooled engines used 

 in a number of airplanes prior to and soon after World War I. An- 

 other fan-type engine of this period was that of Esnault-Pelterie, in- 

 stalled in an unsuccessful airplane in 1907. His "R.E.F." fan-type 

 engines were used subsequently in several successful airplanes. 



An outstanding engine to appear in 1909 was the 50 hp. 7-cylinder 

 "Gnome" rotary-radial, first flown in Henri Farman's No. Ill bi- 

 plane. Rotary types had been built for automobiles by Stephen 

 Balzer and Adams-Farwell in the U.S.A., and this type had been 

 originally planned for the Langley "aerodrome," but it was first 

 adapted to flying in the "Gnome." This engine (text fig. 5 ; pi. 9, fig. 1, 

 and table 2) was a masterpiece for its time and deserves special atten- 

 tion here. 



The design of the "Gnome" (pi. 9, fig. 1) was by Laurent Seguin. 

 Made entirely from steel forgings machined all over, with integrally 

 machined cooling fins and a modern master-rod system, it anticipated 

 many features of the latest large air-cooled radials. The rotary fea- 

 ture was used in order to eliminate the flywheel, which had been pre- 

 viously thought essential, and also to assist in cooling. It frequently 

 used a cowling quite like that later developed for static radials by the 

 N.A.C.A. (see later remarks under "Cooling"). This and subsequent 

 larger and more powerful versions became perhaps the most popular 

 aircraft engines up to World War I and were used widely by both 

 sides throuffh most of that war. 



