Grafting wax, to be used instead of putty in setting water-closets, may be made as follows: Melt and thoroughly mix together, 3 lbs. mutton tallow, 5 lbs. beeswax, 10 lbs. resin. Pour into cold water, and work with the hands until the color of pulled molasses taffy. Keep in a tight can when not in use. This will make a tight joint where the closet joins the lead pipe, and will not dry out and crack like putty.
Cement mortar for setting closets on cement floors, is made as follows: 3 parts Portland cement and 1 part fine sand.
To Harden Cast Iron. Cast iron can be hardened as easily as steel. Use the following formula: 1/2 pint vitriol, 1 peck salt, 1/2 lb. salt peter, 2 lbs. alum, lb. prussic potash, lb. cyanide of potash. Dissolve in 10 gallons of rain water. Stir until thoroughly dissolved. Heat the iron to a cherry red, and dip into the solution. If the iron is to be very hard, reheat and clip the second or third time.
To Inscribe Metal. Cover the part to be marked, with melted beeswax; and, when cold, mark the desired inscription by cutting through the wax down to the surface of the metal. Now, with a mixture of 1/2 ounce of nitric acid and 1 ounce of muriatic acid, fill the inscription, using a feather. Allow this to remain for from one to ten minutes, and then throw on water to check the action of the acids. Remove the wax by heating. This is a good method of marking tools.
To find the area of a rectangle, multiply the length by the width.
To find the area of a triangle, multiply the base by the perpendicular height.
To find the circumference of a circle, multi ply the diameter by 3.1416.
To find the area of a circle, square the diameter and multiply by .7854; or multiply the diameter by the circumference, and divide by 4.
To find the diameter of a circle of given area, divide the area by .7854, and find the square root of the result.
To find the diameter of a circle which shall have same area as a given square, multiply one side of the square by 1.128.
To find the number of gallons in a cylindrical tank, square the diameter, multiply by the height (all dimensions in inches), and multiply by .34.
To find the number of gallons in rectangular tank, multiply the length by the breadth, and the result by the depth; and this result by 7.4 if these dimensions are in feet. If the dimen sions are in inches, multiply by .004329.
The find the lateral pressure of water upon the side of a tank, multiply the area of the sub merged side (in sq. in.), by the pressure due to
the depth. Suppose, for example, a tank to be 12 ft. long and 12 ft. deep, what is the pres sure on the side wall? We have: 144)044= 20,736 sq. in. Since a cubic foot of water weighs 62.5 lbs., then the weight pressing on 1 sq. in.
of the bottom of the cube will be 62.5÷144=.43 lb. And, since the water is 12 ft. deep, we have: 12X .43=5.16 lbs. pressure per sq. in. at bottom of tank. Pressure at top =0; therefore the average pressure on the side of the tank, or the pressure at mid-depth will be 5.16÷2=2.6 lbs., approximately. Therefore, 20,736 x 2.6=53,914 lbs. pressure on side of tank. To find the number of gallons in a foot of pipe of any size, multiply the square of the diameter of the pipe (in inches) by .0408.
To find the diameter of pipe to discharge a given amount of water per minute in cubic feet, multiply the square of the quantity in cubic feet per minute, by 96. This gives the pipe diameter in inches.
To find the power necessary to raise water to any given height, multiply the number of cubic feet required per minute by the number of feet through which the water is to be raised. Then multiply this result by 6.23, and divide by 33,000, which will give the nominal horse-power required. If the amount of water required per minute is in gallons, the multiplier should be 8.3 instead of 6.23.
Another method of finding the horse-power required to raise water to a given height, is to multiply the pounds of water by the height to be raised in feet, and divide by 33,000. Add to this result about 25 per cent to offset friction and other losses.
Water expands about 1/10 of its volume in freezing, and about 1/20 in boiling.
To find the area of a required pipe when the amount and velocity of the water are given, multiply the number of cubic feet of water by 144, and divide this amount by the velocity in feet per minute.
To find the diameter of a pump cylinder to move a given quantity of water per minute, 100 feet of piston travel being the standard, divide the number of gallons by 4, and take the square root of the result. This will give the diameter in inches.
To find the velocity in feet per minute neces sary to discharge a given volume of water in a given time, multiply the number of cubic feet of water by 144, and divide the result by the area of pipe in inches.