48 W. H. WARREN. 
by a single locomotive over a comparatively long mileage, 
provided those grades could be so improved as to permit 
of a considerably increased load for a long haul, at a cost 
on which the interest would be appreciably less than the 
working expenses entailed by carrying much smaller loads. 
As instances, it may be mentioned that the load for all 
trains between Hill Top and Goulburn was ruled by a 
number of heavy grades varying from 1 in 30 to 1 in 40, 
and these existed at eleven points in a distance of 653 
miles, and only in one case was the ruling grade over a 
mile in length, so that about nine miles of heavy gradient 
ruled the load over a total distance of 655 miles. Again, 
between Goulburn and Cullerin five short grades of 1 in 40 
existed which ruled the load for one engine, or demanded 
the use of an assisting engine over a length of 20 miles. 
On examination it was found that the cost of the altera- 
tion would be so small, that the reduction in working 
expenses would pay a considerable interest on the outlay 
involved in the work, the effect of which would be that 
loads could be drawn over practically any other part of the 
section unassisted, could be taken right through the whole 
section without the use of an assistant engine. The same 
principle applies practically to the whole of the grade 
alterations which have been carried out on the main 
Southern, South-Western, main Northern, North Coast and 
North-Western lines. 
The practical] value of these works may be realised when 
it is stated that, on the Southern line, a full load of forty- 
five wagons can now be taken over the whole section 
between Junee and Harden, and between Cullerin and 
Sydney, as against a load of about twenty wagons that 
could be previously taken. On the main Western line the 
works carried out permit of a full load of forty-five wagons 
being taken from Narromine to Wellington, a distance of 
