77 
Ordinary Meeting, January 24th, 1865. 
R. Angus Smith, Ph.D., F.R.S., &c., President, in 
the Chair. 
Mr. William B. Johnson was elected an Ordinary Member 
of the Society. 
Mr. S. B. Worthington, C.E., stated that it might be of 
some interest to the engineering members of the society to 
know, that he had lately constructed a swing bridge for 
carrying a railway over the Sankey canal, in which the girders 
are made of Bessemer steel plates. The object of using steel 
instead of wrought iron, was to reduce the weight of the 
girders. The girders are four in number, about fifty-six feet 
long, with bearings varying from thirty to forty feet, and two 
feet deep. They were manufactured by Messrs. Benjamin 
Hick and Sons, of Bolton, from steel plates made by the 
Bolton Steel and Iron Company ; and were tested with loads 
of a ton to the foot, or more than double the weight which 
they could possibly be called upon to bear. The deflection 
varied from ^-inch to an inch, according to the length of the 
girder, and there was no permanent set on removal of the 
testing load. 
The plates used varied from 5 -inch to iV-inch in thickness; 
and the average tensile strength of a considerable number of 
plates tested, was upwards of thirty-six tons to a square inch. 
The weight of the girders was about f tbs of the weight 
which they would have been if wrought iron had been used. 
PB0CEEDING8 LlT. & PHIL, SOCIETY,—' VOL. IY.— No. 9, — SESSION 1864-5, 
