838 



HYDRAULIC MACHINERY, FOR MINES 



tenaci'.y of the material of the cylinder 10,000, and tho pressure 8,000 Ibs. per square 

 inch, what must be the thickness of the cylinder ? 



Sum of tenacity and fluid pressure 

 Difference of -tenacity and fluid pressure 

 Quotient of sum and difference 

 Square root of quotient . 

 Difference between root and 1 

 Product of radius and difference 



10,000 + 8,000 = 18,000 

 10,000-8,000= 2,000 

 18,000-5-2,000= 9- 

 A/9- = 3- 



3'-l- = 2' 



9-x2- =18 inches. 



Ana, 



To determine the pressure per square inch which a thick hollow cylinder will 

 withstand ; the internal and external radii, and the tenacity of the material of the 

 cylinder, being given : 



EULE. Divide the difference of the square of the radii, and multiply tho quotient 

 by the tenacity per square inch of the material of the cylinder. 



Example. The internal and external radii of a thick hollow cylinder being re- 

 spectively 9 and 27 inches, and tha tenacity per square inch of the material of tho 

 cylinder 10,000 Ibs., what pressure per square inch will the cylinder sustain ? 



Square of external radius 

 Square of internal radius 

 Difference of squares 

 Sum of squares 



27x27 = 729 



9x 9= 81 



729-81 = 648 



729 + 81 = 810 



- 

 810 



= 8,000 Ibs. Ans. 



TABLE I. Pressure of Water at different heads. 



RULE. Multiply head of water in feet by '433 for pressure in pounds per square inch. 

 Example. "What pressure in pounds per square inch will be given by a head of 



500 feet ? 



500 x -433 =216. Ans. 



TABLE II. Weight of cylindrical columns of water, each one foot long, of various 

 diameters, in pounds avoirdupois. 



HYDBAULICS treats of tho motion of water, and HYDRODYNAMICS of tho force with 

 which it acts. 



Descending water is actuated by the same laws as falling bodies ; and will full 

 through 1 foot in of a second, 4 feet in $ of a second, and through 9 feet in $ of a 

 second, and so on. . 



