III. PRIME MOVERS. 385 



III. -PRIME MOVERS. 



1930. Original Model of Stirling's Air-engine. Made by 

 the inventor. University of Edinburgh. 



1931. Hotary Steam. Engine. Designed and made by the 

 Rev. Patrick Bell. 



Lent from the Patent Office Museum by the Commissioners 

 of Patents. 



1932. Sectional Model of a Cabinet Steam Engine. 

 Lent from the Patent Office Museum by the Commissioners 



of Patents. 



This is a sectional model of a steam engine in the Patent Office Museum, 

 and was made for the purpose of showing the following improvements in the 

 ! team engine made by James Watt. (The engine in the Patent Office Museum 

 was the property of James Watt.) Improvements above referred to : 



a. Making the engine double acting. 



b. Keeping the cylinder heated while the engine is at work by surrounding 

 ic with steam. 



c. Using a separate condenser and air pump. 



d. Parallel motion. 



e. The governor. 



/. The D slide valve. 



1933. Drawing of " Head's Patent Prime-mover." 



Jeremiah Head, M.I. C.E. 



Being an inverted, direct-acting, non-condensing steam-engine, with steam- 

 jacketed cylinder and covers, cylindrical slide valves, and variable expan- 

 sion gear, controlled by a liquid- cataract parabolic governor, and balanced 

 throughout for running at a high speed. 



1934. The Locomotive Engine " Rocket," constructed, by 

 Messrs. Stephenson & Co. in 1829, to compete with other engines 

 on the Liverpool and Manchester Railway, where it gained the 

 prize of 500/. The Liverpool and Manchester Railway was 

 formally opened for passenger traffic on the loth September 1830. 



Lent from the Patent Office Museum by the Commissioners 

 of Patents. 



1934a. The Puffing Billy, the oldest locomotive engine in 

 existence, and the first which ran with a smooth wheel on a- 

 smooth rail, was constructed in 1813 by Jonathan Foster, under 

 William Hedley's patent, for Christopher Blackett, Esq., the pro- 

 prietor of the Wylam Collieries near Newcastle-upon-Tyne. This 

 engine, after many trials and alterations, commenced regular 

 working in 1813, and with tender and two trucks, a total load 

 3950S. Bb 



