170 Long^s Steam-Pump. 



by the pressure of a small quantity of water in the reservoir 

 STVX. A small aperture abed is made in the side of the 

 reservoir, by which the water may be conducted away. 



The mode of operation will be easily understood. The 

 barrels EF are first filled with water through the tubes L, 

 which are then securely stopped. The reservoir is filled with 

 water up to the level CD, high enough to close the valves N. 

 By turning the valve R, steam is admitted into the receiver 

 IH, and the air which this contains is expelled through the 

 valve N. As soon as this is effected, the valve R is again 

 turned, so as to cut off the steam from IH, and admit it into 

 I'H'. The air is then expelled from this receiver through the 

 valve N', while the steam contained in IH is condensed by 

 contact with the upper part of the pipe EF. A vacuum be- 

 ing thus formed, the water rises through the suction pipe EF 

 and fills the receiver. The valve R is now turned again ; — 

 steam is admitted at O, and the water in IH is discharged 

 into the reservoir by the valve N, while the steam in I'H' con- 

 denses and that receiver becomes full of water. Thus each 

 receiver is alternately filled and emptied. 



A method of regulating the admission of steam, independ- 

 ently of manual assistance, has also been invented by Lieut. 

 Long, which may be considered as completing the apparatus. 



As the water is raised in the barrel EF by atmospheric 

 pressure, and it should ascend with a certain velocity, the 

 height to which water will be elevated when the greatest ef- 

 fect is produced will be about twenty or twenty five feet. 

 With receivers of a capacity of sixteen cubic feet, one being 

 emptied every ten seconds, six thousand pounds of water 

 might be raised to this height in a minute : an effect about 

 equal to that of a four horse power. 



The apparatus evidently requires no great strength of ma- 

 terial or nicety of construction. Its first cost will therefore 

 be small. But few of its parts are liable to get out of order, 

 and those may be easily repaired or replaced. The press- 

 ure of the steam need exceed that of the atmosphere but 

 little, and the quantity of it necessary exceeds that of the 

 water to be raised only by an allowance for wastage occa- 

 sioned principally by condensation, while in contact with 

 the discharging water and the sides of the receiver. The 

 amount of this loss, it may not be easy to estimate exactly 

 without the actual experiment ; but if the discharging orifice 

 be made large, it will not, perhaps, be so great as to balance 

 the advantages of the invention. H. H. G, 



