OF IRON BCAM3. 903 



69. The following experiments were made 

 after the paper was read, but are incorporated 

 with it, as they will give additional evidence 

 to some of the preceding conclusions. In 

 these the lineal dimensions of some of the 

 beams were considerably increased, and more 

 varied, agreeably to a suggestion of Mr. 

 Ewart*s, and which I was glad to accede to, as 

 Messrs. Fairbairn and Lillie were desirous of 

 affording every means of a full investigation. 



The beams were in this instance, cast on their 

 side, in the manner of those in the first six 

 experiments on beams; it being rather more 

 convenient to cast them so, than erect, as has 

 been usually done in the others. The intention 

 of these experiments would perhaps be under- 

 stood by first taking the three marked 28, 29, 30, 

 and then the next three. I will, however, give 

 the following explanation. 



In experiment 28, the model from which the 

 beam was cast was that of experiments 19 and 

 20, with the bottom rib still further increased ; 

 the vertical part of the beam, or that between 

 the flanges, being rendered a little thicker, and 

 tapering upwards from the bottom flange. This 

 was done to endeavour to prevent fracture taking 



I 



