Hermes bags

of rivets, as at L in Fig. 2149. The consequence is the bending of the pHermes bagslate at the point J, as in Fig. 2149, each time of being under pressure of steam, owing to the outer line of rivets L being entirely outside of the line of strain S of the boiler-plates. Thero is also a great tendency to injury of the angle-iron, by this action tending to split it between the rivet-holes at the outer line of rivets L.
The present plan adopted on the Midland Railway is found to obviate the injury previously experienced from corrosion; and this is accomplished by the use of plates rolled with thickened edges, as shown in section in Fig. 2150, and shown exaggerated in thickness in Figs. 2151, 2152. The ordinary thickness of ^ in. is preserved in the bHermes Birkin ody of the plate, and the edges are thickened to $ in., with a long gradual taper in the thickness from I to I, Fig. 2150, about 4 in. long. The effect of this long taper is that, when the plate is flanged, as at N, in order to do away with the angle-iron,
the taper ensures a gradual springing of the plate, distributed over all that length, instead of the sudden bending concentrated at one point, as at J in Fig. 2149.
A similar section of thick-edge plate is also used at the transverse circular joints, as shown in Figs. 2151, 2152, cHermes outletusing a gradual springing of the plates over a considerable length when under pressure, as in Fig. 2152, instead of the former sudden bending at one point, as in Fig. 2149. There is also an increased strength gained by this mode of consHermes Kellytruction, as the increased thickness of the plates between the rivet-holes compensates for the loss of section by the holes.
The practical working of the thick-edge plates is shown by the specimen No. 306 engine in the preceding Table. The original boiler of this engine, constructed in the ordinary manner, was removed after 11J years' working, as the plates were mBirkinuch grooved and pitted; and a new boiler, constructed with the tHermeshick-edge plates, was substituted, which has continued at work 6£ years. It was then found that the plates were free from grooving, although they were badly pitted.
A consideration of the ordinary construction of locomotive boilers and their defects shows that their construction admits of important improvement in the barrel, by removing the injurious strains resulting from the employmHermes Handbagsent of lap-joints, which throw the plates out of the line of strain, and by making the barrel truly cylindrical and circular throughout. These objects are effected by welding the longitudinal joints of the three rings forming the boiler barrel, and making these rings