ECONOMICAL CARGO SHIPS. 97 



Mr. Robertson does well to direct attention to the painful results of undue detention in 

 port, and he confirms tiie conclusions previously found. This again emphasizes adequate 

 handling gear and terminal facilities as a necessary accompaniment to successful operation. 



If the deficiency in handling is attributable to the ship, it is the owner's loss; if to the 

 port, while the ship may be able to charge higher freight rates, the port suffers to that extent 

 in the shape of higher prices for the article shipped. 



It would be interesting to take the time necessai-y to compare the different standard ships 

 built in large numbers and analyze them by the methods adopted in this paper. This would 

 be somewhat laborious ; but it can be safely concluded that the main points here brought 

 out are confirmed in practice. 



Values are changing so fast these days that any set of figures assumed would be incor- 

 rect and perhaps radically so in a few months' time. The value of this paper is not affected 

 by such variations to any material extent ; it furnishes us with one method of analysis which 

 can readily be corrected for changes in values. The fundamentals of size, speed, power, ca- 

 pacity, etc., remain constant, leaving the variables only to be re-figured from time to time as 

 occasion requires. 



Mr. Spencer Miller, Member of Council: — I wish to ask the author to point out how 

 one can use his tables to arrive at the cost per ton of waste material carried on any ship ; for 

 example, suppose by improved apparatus the water, the coal, or the oil fuel carried on board 

 ship could be reduced by one ton,. What is the value of such a ton of weight saved ? Sup- 

 pose that certain machines (be made of steel instead of cast-iron and thus reduced in weight 

 to the extent of one ton, how much saving in money will be effected by such a reduction in 

 weight over a period of say ten years? 



The President: — ^Is there any further discussion? If not, we will ask Mr. Robertson 

 to close the discussion on his paper. 



Mr. Robertson : — I do not think I have much to say now, except to thank the gentle- 

 men cordially for their addition to the contribution involved in this paper. The information 

 that Mr. Rigg has presented to us has considerably enlarged the interest of the paper. 



In answer to Mr. Miller I will say that the figures presented in the paper are drawn up 

 in such a way as to allow an accurate estimate of the effect of a single ton of difference in 

 the deadweight, or in the weight of structure of the ship. It is a mere matter of arithmetic 

 to arrive at what the amount would be. 



The following is an example of calculation of cost of one ton in the economical oper- 

 ation of a ship : — 



Take Column 4, Plate 39; the cost of operation of this ship is (line 49), per million 

 dollars invested, $380,440; and the earnings are figured (line 53) at $175,613, making 

 $556,052 gross earnings per million dollars invested. The total cost of this ship, however, 

 is only $784,330, so that the earnings would amount to $436,128 with a cargo deadweight 

 of 5,299 tons. 



Each ton of deadweight therefore will be required to earn $82.30 per annum, and if 

 one ton were lost in the ship due to uneconomical employment of material, the sum of $82.30 

 per annum; would be lost under the conditions assumed. 



The value of this sum in twenty-five years, the assumed life of the ship, including 



