124 F. M. GUMMOW. 



steel joists 12 inches x 6 inches x 12 feet long were used 

 for each pier to rest upon. The piers 5 feet 8^ inches long 

 x 1 foot 10 inches thick x 2 feet 11 inches high to the top 

 of plate were built of ordinary bluestone concrete a few 

 days before the plate-beams, and had dovetailed recesses 

 left in them for the beams and the plate to rest in. Two 

 types of plate-beams were employed, with the object of 

 ascertaining and comparing their values, the plate being 

 made continuous across the two. Both beams were 23 feet 

 C inches span between piers, or 27 feet 2 inches over all, 

 1 loot 10 inches deep at the centre, and 1 foot 4|- inches 

 at the supports to the under side of the plate. The latter 

 was 2i inches thick, making total depth of 2 feet 1 inch and 

 1 foot 7 inches respectively at the centre and ends. Beam 

 A was 10 inches wide, reinforced with five round iron bars 

 placed about liV inches above the under side. Three of 

 these bars (one |- inches and two J inches) extended along 

 the lower side throughout into the recesses. The remainder, 

 viz., two | inch bars, extended only for a certain distance 

 along the lower side, thence upwards toward the upper 

 surface and then along the latter into the support. 



Each bar was in one length from support to support and 

 bent over at the ends. Additional bars f inch diameter, 

 and 5 feet 6 inches long were inserted near the top surface 

 one at each support. Beam G was 7 inches wide reinforced 

 with six round iron bars. One J inch diameter and two f 

 inch diameter bars were situated l-h inch above the lower 

 surface of the beam and extended along same into the piers. 

 The other three } inch bars placed 2f inch above the lower 

 surface of the beam extended only a certain distance along 

 such, thence upward toward the upper surface and along 

 the latter into the piers. These bars were also continuous 

 throughout their lengths and were bent over at their ends. 

 Additional bars f inch diameter and 5 feet 6 inches long 



