LIGHT RAILWAYS FOR NEW SOUTH WALES. ea 
four coupled wheels was only ten and a half tons. Such engines 
were useless for lifting paying weights over grades. The total 
gross weight that an engine of this sort could lift behind it over 
grades of one in forty at ten miles an hour was fifty tons of 
waggons and loading, so that to meet all expenses for wages, fuel, 
and stores, repairs of rolling stock, maintenance of way, supervision, 
interest, etc., they would get the rates derivable from only twenty 
to twenty-five tons of merchandise per train hauled. He gave 
these figures to show that the elevated railroad engines, which did 
so well under the conditions for which they were designed, would 
be practically useless on any light lines in New South Wales. But 
there was no difficulty in making locomotives flexible enough to 
work freely round any reasonable curves, provided a sufficiently 
good track was laid for them. They had, at the present time, 
English-built locomotives in this Colony, which weighed fifty-seven 
tons, carried on twelve wheels, spread over a wheel base of twenty- 
nine feet two inches, but of which the rigid base was not necessarily 
more than six feet two inches. These engines were certainly 
flexible enough, but they were no more disposed naturally to run 
in circles than the most rigid engine ever built. Locomotives, 
like other bodies in motion, followed the laws of nature, and 
moved in straight lines unless forced to change their direction by 
pressure and loss of power. This law of nature could not be 
overcome by merely making each axle radical to the curve. The 
pressure between the wheel flanges and the rails remained the 
same, and that pressure, with sharp curves, meant destruction of 
tyres and rails, limitation of loads, and high working costs. 
In South Australia many miles of light lines had been built on 
the five feet three inches gauge. They were laid with iron rails 
originally of only forty pounds to the yard, but considerably worn, 
and engines were specially designed for moving a fairly heavy 
traffic over these light rails. They were tank engines, with six- 
teen and a half inch cylinders, carried on ten wheels, on any pair 
of which the greatest load was eight and three-quarter tons. The 
total weight of each engine was forty and a half tons, and they 
