The stay across the link of a chain increases its strength about one-sixth.
When the chain is of great length, a deduction, from the above rules, must be allowed for the weight of it.
IRON RODS.
To find the weight of round iron rods.
Divide the square of the diameter, in quarter inches, by 2, and the quotient will give the weight in pounds, per yard.
Example.—What is the weight of a yard of 1-inch round iron.
1 inch = 4 quarters 42 = 16 16 2 = 8 lb. Weight required.
To find the weight of square rods.
The weight of round rods, of similar diameter, divided by ·7854 will give the weight of the square rods.
To find the weight that may be sustained, or lifted by round iron rods.