882 PROCEEDINGS OF SECTION J. 



contonr lines every ten feet in height Avould be constructed, 

 and tiie surface g-rade line laid down from these contours, 

 upon Avhich data the best possi1)le narrow gauge line would 

 be determined. 



This system of contours is illustrated, and the g'eneral 

 effects seen on the plans and section which accompanied my 

 Report, and which the Engineer-in-Chief in Tasmania has 

 been good enough to lend for the purposes of this paper, and 

 which are now at hand ready to be explained if any gentle- 

 man so desires. 



By this system you have the survey for all time of a 

 standard gauge railway, and the necessary data for laying 

 down the narrow gauge line, at little more than the expense 

 of one survey ; and it would be difficult country indeed 

 where curves of 2^ or 3 chains radius would not follow at the 

 engineer's pleasure the surface grade line, or at least entail 

 only very shallow cuttings and enbankments, and do away 

 with tunnels, long culverts, and heavy viaducts. 



The other points to be emphasized are the great saving in 

 cost and time in constructing the lines. Let us take, for 

 instance, three of the lines lately in course of being surveyed 

 in Tasmania, viz., the Derwent Valley extension to Zeehan, 

 the extension from Mole Creek to Zeehan, and the Waratah- 

 Zeehan Railway, altogether about 280 miles. These, on the 

 standard gauge, would cost the country say £1,680,000, and 

 if done simultaneously would take at least six years to com- 

 plete, whilst on the narrow gauge the cost to the country 

 would be reduced to about £680,000, and if done simul- 

 taneously the time would be reduced to about two years ; so 

 that there is a million of money to spare for another 400 miles 

 of railway to still further open up the country, and the 

 interests of the nation would be advanced by four years. In 

 this period of economy there is no economy more required 

 than in railway extension in countries where traffic is an 

 unknown quantity, and which yet must be opened up; and if 

 railways are constructed on a narrow gauge at small cost 

 which will carry all the possible traffic for the next 20 years 

 or more, why should we spend the enormous amount required 

 for a standard gauge line, which will carry no more traffic, 

 because there is no more to be carried? The one Avould very 

 probably yield some return, the other most probably would 

 have difficulty in paying its way. 



The immense reduction in the first cost, of time in con- 

 struction, and the resulting more speedy opening up of the 



