# Leffel's Construction of Mill Dams: And Bookwalter's Millwright and Mechanic

J. Leffel & Company, 1881 - 283 Seiten

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Seite 158 - To find the pressure in pounds per square inch of a column of water, multiply the height of the column in feet by .434. Approximately, we say that every foot elevation is equal to % Ib. pressure per square inch ; this allows for ordinary friction. To find the diameter of a pump cylinder...
Seite 146 - ... subject to variation according to circumstances; but the rule ordinarily adopted is to make the crown from 3 to 5 feet above high water mark. The breadth of crown is still more variable, ranging in different localities from 3 feet to 12 feet or more, the latter being an exceptional figure. CHAPTER XL1X. RACE AND RESERVOIR EMBANKMENTS— CONTINUED. The necessity of adapting the slope of an embankment, especially on the water side, to the disturbing causes which will operate upon it, and the fact...
Seite 158 - To find the diameter of a pump cylinder to move a given quantity of water per minute (100 feet of piston being the standard of speed), divide the number of gallons by 4, then extract the square root, and the product will be the diameter in inches of the pump cylinder. To find quantity of water elevated in one minute running at 100 feet of piston speed per minute.
Seite 159 - The area of the steam piston, multiplied by the steam pressure, gives the total amount of pressure that can be exerted. The area of the water piston, multiplied by the pressure of water per square inch, gives the resistance. A margin must be made between the power and the resistance to move the pistons at the required speed — say from 20 to 40 per cent., according to speed and other conditions.
Seite 182 - Rule. — Multiply the diameter of the driver by its number of revolutions, and divide the product by the diameter of the driven; the quotient will be the number of revolutions of the driven.
Seite 250 - ... which causes their angular velocity of revolution to bear a fixed ratio to the velocity of the prime mover. The rods of the pendulums place themselves at an angle with the vertical axis, so that the common height of the pendulums is that corresponding to the number of turns in a second.
Seite 246 - CEMENT FOR LEATHER BELTING. — Common glue and isinglass, equal parts, soaked for ten hours in just enough water to cover them ; bring gradually to a boiling heat, and add pure tannin until the whole becomes ropy or appears like the white of eggs. Buff off the surfaces to be joined, apply this cement warm, and clamp firmly.
Seite 234 - London; and to fall these eight hundred feet, in its long course, the water requires more than a month. The great river Magdalena, in South America, running for a thousand miles between two ridges of the Andes, falls only five hundred feet in all that distance. Above the commencement of the thousand miles, it is seen descending in rapids and cataracts from the mountains.
Seite 242 - Measures of Weight The standard AVOIRDUPOIS POUND is the weight of 27.7015 cubic inches of distilled water weighed in air at 39.83° F., with the barometer at 30 inches.
Seite 158 - To find the velocity in feet per minute necessary to discharge a given volume of water or liquid in a given time, multiply the number of cubic feet of water by 144, and divide the product by the area of the pipe in inches.