]847.] Hydraulics for Farmers. 305 



of the machine, as aforesaid, and the pressure of the external at- 

 mosphere on the valve B, will cause it to open again. The water 

 from the head then flows through this valve with an accelerating 

 movement, until it has acquired that degree of velocity as to cause 

 the valve to close. The water having no longer any vent through 

 the valve B, passes through the opening O, into the pyramidal air- 

 chamber L, and repeats the operation above mentioned, succes- 

 sively. 



In this manner the operation will continue as long as the ma- 

 chine remains in order, and there is a head of water to propel it. 

 The valve V is for the purpose of supplying the chamber 1 with 

 air, by admitting said air into the tube P. The said air is admit- 

 ted during the time that the partial vacuum above mentioned takes 

 place. The air thus introikiced into the tube P, ascends to the top 

 of the same, and is forced into the chamber I, at the next stroke 

 of the machine; said valve V is represented open in Fig. 7, and 

 may be closed or regulated by screwing the thumb-screw V. 



The principal advantages this machine possesses over other 

 machines, are: 



1st. In case of forcing up pure water by the propelling power 

 of a running stream of water less pure, there is no possibility of 

 the impure water mixing with the pure, there being at that time 

 a column of condensed air between the two wateis. 



2nd. The water being forced into the upper chamber I, by the 

 condensation of air in the lower chamber, the valve J opens more 

 slowly than when water alone is made the propelling medium, and 

 also shuts more slowly, thereby preventing the water from escap- 

 ing back through the valve J, after it is forced up; the valve J 

 being nearly closed when the water ceases to flow upward into 

 the chamber I. This advantage, upon trial, is found to be of con- 

 siderable importance, enabling the machine thus operated, to force, 

 with a given quantity of water, several barrels more of water per 

 day than it would otherwise do. 



3rd. There being no valve between the condensed air in the 

 lower chamber and the driving water, or at the opening 0, said 

 air is permitted to act a longer time in forcing back said driving 

 water, and thereby making a more complete vacuum than in other 

 machines, and rendering useless the spring for opening the outlet 

 valve B, as used in several machines. 



It is not necessary that the spring water chamber N, and the 

 air-chamber L, should be enclosed by the same envelope, but they 

 may form separate chambers, and they may be arranged in any 

 convenient way or manner most acceptable to the constructor, 

 provided that the capacity of the air-chamber does not exceed a 

 due ratio between the propelling power and the \vater to be 

 raised. 



