LIGHT RAILWAYS FOR NEW SOUTH WALES. 247 
of rolling stock to be run over it or vice versa, and again this would 
depend entirely on firstly, gradients, secondly, probable amount of 
traffic, and thirdly length of line, whether a short branch service 
or the prolongation of a main trunk line with intermittent heavy 
traffic ; if of the latter, it should be of sufficient strength to carry 
the usual class of rolling stock in use on that line. In any case it 
would be a fatal error to have the line so weak that only one 
special class of engine could be run over it as in the event ofa 
break-down duplicate stock must be kept ready. As the tendency 
in the past had been always for enlarging and not diminishing 
the weight and power of the locomotives it must be taken as a 
self evident fact of the beneficial result which has been gained by 
experience, of having powerful motors. 
He was of opinion that for intermittent heavy traffic the ballast 
might be four inches under the sleeper, and except on sharp curves 
three inches up the side or seven inches altogether, and on curves 
of small radii the sleepers should be covered. The number of 
sleepers taken with the weight of rail must be entirely guided by 
the weight to be carried on each axle. It was on the item of. 
permanent way where a very large percentage of saving or other- 
wise could be made. The difference in cost in rails only between 
a forty pound and a sixty pound was £200 per mile, but with the 
same number of sleepers the latter would carry double the load of 
the former, and would therefore allow of steeper gradients if 
required, and be capable of doing more work, at the same time 
employing the usual rolling stock. Ifthe light rails were adopted 
every ten miles would approximately pay the first cost of a light. 
engine to work it for the same amount of money. Yet except. 
under peculiar circumstances of, say a short branch line, it seemed 
the best policy and the most economical to have at the least sixty 
pound rails with eleven sleepers for each thirty feet of rail, equal 
to one thousand seven hundred and sixty sleepers per mile. The 
author of the paper proposed to use screws only for the joints, 
they might be dispensed with altogether, the dog spikes being 
quite as good ; he also proposed to abolish platforms, this being 
