LIGHT RAILWAYS FOR NEW SOUTH WALES. 235 
accounted for the peculiar action mentioned, by the insufficiency 
of superelevation. He might here mention that this lifting of 
the wheel off the inner rail was an evidence of the extreme 
pressure between flanges and rails caused by curvature. The 
pressure between the bogie wheel flange and the outer rail, due 
to the forcing of the engine out of the straight line of motion, 
was sufficiently great, when acting through the leverage of half 
the diameter of the wheel and the length of axle, to compress 
the bogie spring over the inner rail and allow the wheel to lift. 
Another matter, which had always appeared to merit more atten- 
tion than it received, was the width of gauge on curves. He was 
of opinion that it was a mistake to widen the gauge, and would 
prefer to give no play. When vehicles were running round curves, 
the leading axle always slewed over towards the outer rail and 
the trailing axle went in the opposite direction or towards the 
inner rail, until their respective movements were checked by the 
pressure between the tyre flanges and the rails. Thus a short 
_ vehicle took np a position diagonal to the curve, and the wider 
the gauge the greater that divergence, which in many cases made 
the flange cut into the edge or side of the rail like a knife, and 
where the head had been worn away (as shown by the sketch ““B”), 
which was always the case more or less on curves, the inclined 
direction of the worn head readily assisted the wheel to rise 
(especially under light loads or empty vehicles) and lift over the 
outer rail. He considered that many derailments, otherwise 
inexplicable, were due to that cause. 
Colonel WELLS said that having been for some years principal 
road engineer in the Colony, a few words from him in that rela- 
tion might not be out of place. Since inland communication had 
of late been demanded and carried so far into the western interior, 
the necessity of other connections than common roads had become 
apparent to such an extent that the late Commissioner for Roads, 
Mr. Bennett, and himself had deprecated all attempt at making 
roads on the great black plains, but bad advocated light railways 
instead. In many localities road material, even of the poorest 
