38

Since g is the weight of a part of thependent bearers measuring one inch square,and n the number of square inches in thesections of all the pendent bearers, we haveng = the weight per foot superficial of thependent bearers.

y — the ordinate of the catenary.

% — half the length of the catenary.

<p = the angle which the catenary makeswith a horizontal line at each pointof suspension.

t = the measure of the tension of thebearers at the points of suspen-sion.

c ~ the measure of the same at the apex,which is constant.

m=2.302585=:the number by which thecommon logarithm of any numbermust be multiplied to obtain thehyperbolic logarithm of the samenumber.

Then w= 1627, g , =54.083, or 8.587, or5.868, or 4.166, according to the materialused; f- 224000, or 21056, or 40000, or48000, or 68000, according to the mate-rial used, and t/=250 * <£>=7°"10'.