HUMPHREY INTERNAL-COMBUSTION PUMP 259 



that no internal-combustion pump had proved successful when 

 Mr. Humphrey took up the problem and introduced an entirely 

 new principle into engineering which promises to revolutionise 

 the present methods of pumping water. 



The genesis of Mr. Humphrey's ideas is interesting; they 

 were largely the consequence of the failure to give the gas 

 turbine practical shape. Mr. Humphrey had spent much time 

 on the gas-turbine problem and the apparently hopeless results 

 led him to devise some other means of converting gas power 

 into mechanical power. He came to the conclusion that the 

 energy of a combustible mixture might best be used to put 

 water under pressure or to raise it to a height : hence most 

 of his numerous patents bear the title " Improvements in 

 Methods of raising or forcing Liquid and Apparatus therefor." 

 An examination of his patents leads one to conclude that as 

 regards broad principles he has covered the whole range of 

 application. The claims run into hundreds : in an article of this 

 kind it would be out of place even to quote a few of them ; 

 instead, we shall endeavour to explain the more general features. 



Briefly stated, Mr. Humphrey's invention consists in utilising 

 the energy of expansion of an ignited combustible mixture to 

 cause the free reciprocation of a column of liquid in a play-pipe, 

 the momentum of the moving column being utilised to carry 

 through all the functions of a complete cycle. In many cases 

 the explosion takes place in direct contact with one end of the 

 liquid column but this is not a necessary condition, though 

 the absence of solid pistons makes the simplest arrangement. 



In the first Humphrey Pump which we shall describe, which 

 is suitable for a direct lift without suction, the water column, 

 which also acts as both piston and fly-wheel, has four unequal 

 strokes such as theory requires when expansion is carried 

 to atmospheric pressure. These strokes are : a long stroke 

 during combustion and expansion, another long stroke during 

 exhaustion, a shorter stroke during suction and a still shorter 

 stroke during compression. There is no valve across the play- 

 pipe (sometimes called the discharge pipe) at any point, so that 

 the water has a free passage from the explosion chamber to the 

 water tower, whence the water is led away at the higher level. 



The action of such a pump can be best explained by reference 

 to fig. 1. The pump proper is built up from three main 

 castings:— c is the combustion chamber connected by means 



