THE HUMPHREY INTERNAL-COMBUS- 

 TION PUMP 



By HUGH DE P. BIRKETT, B.Sc. 



The raising of large quantities of water with a minimum of 

 fuel consumption has constituted an important problem ever 

 since the introduction of the steam engine, as witness the 

 Cornish Pump and the many modifications of steam pumping 

 machinery since made. The record for fuel consumption per 

 horse-power has long been held by steam pumping plant ; it 

 was only on the introduction of the steam turbine that superior 

 results were obtained and the electric station beat the pumping 

 station in economising fuel. The improvements effected recently 

 in internal-combustion engines have made still greater economy 

 possible and such engines now hold the record. There are 

 few types of pumps, however, which can be coupled directly 

 to gas engines with advantage and in any case the use of such 

 a combination is far from ideal. 



Granted that the principle of internal combustion leads to 

 the maximum economy, the problem that many inventors have 

 endeavoured to solve is that of combining in a simple apparatus 

 both gas engine and pump. No practical solution of this 

 problem was found prior to the inventions made by Mr. H. A. 

 Humphrey, M.Inst.C.E., in 1906 and the following years. Pre- 

 viously every inventor had provided that the explosion should 

 drive the water to be pumped past a non-return valve or valves, 

 so that water could not return ; this was natural, as these are 

 the lines on which all ordinary pumps are constructed. Again, 

 too little attention was given to the question of compressing 

 the combustible mixture before ignition, although the increased 

 efficiency which such compression involved was fully recognised 

 in connexion with ordinary gas engines. Explosions give rise 

 to very rapid increases of pressure and apparatus in which a 

 heavy liquid like water has suddenly to open valves and be 

 driven through valve ports under violent impulses is necessarily 

 liable to trouble and disaster. It was therefore not surprising 



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