On tTte'lPrini'ipUs of Piunp-JFork. Q93 



Scaic" will r^ise water to the height df 2D^ x 14 = 413 

 inches or 31 feet 5 inches, as at F (fig. 2). 



'23. \Yheti the air is heaviest the mercury rises to 31 

 inches 'nearly, cotrespohcling to which is 36 feet ot water 

 ill the pipe at D (fig. 2). 



2B. Ant! iii the ligluest 'slate of the air the niereiiry rises 

 but A litVlc above 2S iiich'es", to'whichi in the pipe of water^ 

 answers ab(>ut S^i at G.'' 



27.. Hence the greatest h'eight!' to' Which water can be 

 raised by a pump will he less Than sd ie'et, laild it inaV al- 

 ways be raised to thti height of '30 fdet'at least; 



Fig. 4. 



' 2S. Suppose A be a reservoir of waterj with a pipe AC ; 

 then upon AC, as a diameter, describe the semi-circle 

 ABC, and from anv point U tlicrcin.kt fall the perpendi- 

 i.'nlari)K; and join A. 1) and D C. . ,; r,.l'i 



29. If now a hole be made at E, the water .■*• ill issue out 

 with a' for-je proportional to the height AE of the fluid 

 aboxje. : 



30. The velocity of the efiiuent water will be as the 

 -scpiai-e root of the hciglu AE, and with an uniform velo- 



citv. 



- 3-1 » The time of its descent from E to the horizon at H, 

 will be as the scjuare root of the. perpendicular descent EC, 

 or height of the fall. 



32. The horizontal distance CO, to which the water 

 will spout from a hole N in the centre^ is equal to A C, the 

 altitude of the water. 



33. If we take N'F = XE, then water spouting from 

 holes at E and F will go to the 'same horizontal distance 

 Cfl, which will in all eases be less than CO. 



34. The form of the curve EKMHj which the. spouting 

 fluid describes, is that called a parabola. 



35. The weight of a cubic foot of water is'fi24-lb. avL*r- 

 diipoise weight ; hence the weiglit of a cvlihdrical foot is 



Fig. 5'. .'. ; '; 

 30. If a pipe or tube ABDC bfe plated' in water at A, 

 and a plane at AC which exactly fits it, and moves freely 

 in it, be suspended by a rod or wire fixed at D to the end 

 of a lever DE, wliose fuleruni or centre of motion is F. 

 Then supposing the tube filled to the top with water, let it 

 be equipoised by a weight HGI hanaing from the other end 

 of the balance at E. Therefore if The'tube AB b;; 12 feet 

 high, 12 iiuhes in diameter, and of a cylindric form or 

 T 3 ' bore, 



