250 



Hydraulic Ram. 



Vol. XI. 



the syphon equal to 30, it will follow that 

 the same power will produce three times as 

 much motion or velocity in the short tube, 

 as it will in the long one. If the motion in 

 b is equal to 9, that in fg h will be only 3. 

 Now the momentum is found by multiplying 

 the weight by the velocity or motion — there- 

 fore 10 X 9=:90, the momentum of the wa- 

 'ter in b: 30 x 3=90, the momentum of the 

 water in fg h. Hence the acting force of the 

 straight tube and the syphon are exactlyequal. 



"A fall of one foot or more may be ob- 

 tained in any situation by partly burying the 

 ram, so as to place it lower than the feeding 

 reservoir, and the escape of the waste water 

 will not impede the working of the valves; 

 for I have made it work at the depth of two 

 feet under water." 



We have already seen that the motive 

 power of the ram is equal to a perpendicu- 

 lar column of water of the height of the fall 

 employed — or h i. Now suppose the well 

 i n p to be dug on a level plain / p, and 

 the ram placed in it ; it is evident that the 

 waste water would accumulate upon the 

 machine. The effective power would now 

 be a variable quantity, constantly diminish- 

 ing as the water accumulates, until the well 

 is filled to the level of the reservoir, when 

 the water would cease to flow through the 

 pipe b. If the fall h i was more than the 

 ram required, it would continue to work for 

 a longer or shorter time beneath the surface 

 of the waste water. For instance, if the 

 fall q i was sufficient to move the valves, it 

 would continue to operate until the water 

 rose to q r, and then it must stop. It is 

 therefore entirely fallacious to talk of bury- 

 ing the ram and then drowning him, unless 

 there is more than the requisite fall at com- 

 mand — and then it would be unnecessary. 



" The forcing power of the air vessel will 

 increase in proportion to the enlargement of 

 its horizontal area." 



It is the momentum with which the water 

 enters the air chamber, which compresses 

 the air, and imparts to it its spring, or fore 

 ing power. The column of water in the 

 eduction pipe, is a counterpoise to this mo 

 mentum, and affords a correct barometrical 

 measurement of its force. This force can 

 not depend in any degree upon either the 

 form or size of the chamber — there can be 

 no relation whatever between them. 



By increasing the superficial area of the 

 chamber, we add greatly to the expansive 

 force or bursting power of the air and water 

 contained in it — for it is known that fluids 

 press equally in all directions, and conse- 

 quently, that equal areas of the vessel will 

 sustain equal degrees of pressure. The 

 bursting power of the chamber is represent- 



ed by the quotient of the area of the educ- 

 tion pipe, divided into the superficial area of 

 the chamber, multiplied by the weight of 

 the perpendicular column of water in the 

 eduction pipe. I will make two suppositions: 

 1st. A cubic chamber of 3 inches, 

 area, = 54 " 

 area of pipe, .25 " 



weight of column, 20 pounds, 



-51- = 216 X 20 = 4320 » 

 .25 ^ 



2nd. A cubic chamber of 18 inches, 

 area, = 1944 " 

 area of pipe, .25 " 



weight of column, 20 pounds, 



1944 



^g- ^ 7776 X 20= 155520 " 



Hence it appears, that by increasing the 

 linear dimensions of the air chamber six fold, 

 the bursting power of the air is increased 

 thirty six times. Or, as the squares of its 

 linear dimensions. This may be a useful 

 hint to operatives, and will perhaps explain 

 better than the syphon can do, why Straw- 

 bridge's " machine burst with an explosion 

 like that of a swivel." Montgolfier. 



Sylvania, Second mo., 1847. 



In addition to the two preceding Communications 

 on the syphon, another was subsequently received from 

 a much valued friend near West Chester, Pa. It did 

 not seem necessary to insert the whole of this last. 

 In the course of his letter he says: — 



"There is no occasion for any one to hesitate about 

 introducing the Ram for want of fall, for almost any 

 farm will yield fall enough for the purpose by a little 

 digging, and three feet, with a good head will be ample 

 for slight elevations, say to thirty feet, or even more. 

 I placed one on my farm last spring, which has 

 been in operation since' that time; the fall for the 

 working of which was gained by sinking the ram three 

 feet or more below the surface, and carrying the waste 

 water away by means of a drain. The length of tren- 

 ches dug to attain eight feet fall in this way, was 

 something more than 260 feet. With the fall thus ob^ 

 tained, my supply of water is driven through about 

 1400 feet of lead pipe to an elevation of 115 feet, at the 

 rate of fourteen barrels per day. The cost of thus in- 

 troducing water to my barn, has been $225, as near as 

 may be; the interest on which is $13.50, a cheap 

 method of insuring a constantly flowi)]g stream of 

 water, to which your cattle can resort at pleasure. 



" For trifling elevations any of the many rams now 

 offered to the public would be found efficacious, but 

 when considerable height and great distance are com- 

 bined, it would be advisable to consult some one who 

 is scientifically acquainted with the laws of the mo- 

 tions of fluids, least the too hasty adoption of false 

 principles should end, as it surely will, in disappoint- 

 ment." 



In the first column of page 218 of last number of the 

 Cabinet, and the 35th line from the top, an error oc- 

 curred ; 80 should be 30.— Ep. 



