1840.] 



On Low Steam Power io Vessels, instead of Sails, 



•237 



months, 870 tons, or 500 tons per annum at 16 S 400 



Total cost per annum 2776 £ 



But as the sailing vessel takes 303 days to run that distance, 

 while the steamer would take only 204, there would be 99 

 days saved out of the 23 months occupied by the former in 

 her voyages; and while the former run 13,800 miles in the 

 year, the latter would run 16,200 in that time ; hence 



£ 



Proportional expence of steaming 13,800 miles.... 2360 



Expence of sailing do. as before 2151 



Do. of steaming above sailing , 210 



That is ; the expenre of working a vessel of 380 tons, with a sieam 

 power of one horse to 7| tons, would exceed that of s dling the same 

 distance, or of steaming with a power of 1 horse to 13 tons, by £210 in 

 13,800 miles or by about yV^^- 



Thus it appears that there is a certain speed at which steain vessels 

 can be worked as cheaply as sailing vessels, but at a little higher speed, 

 the steam power is more expensive. 



The loss of freight in consequence of the space occupied by the coals 

 and engine, must next be calculated. 



Tons 



Coal for 2,400 miles as before, being 1 8 days at i\ tons per day. 76 

 Engine 30 



Total tons , 106 



Deduct as before on account of saving in ship's stores 40 



Loss of tonnage 66 



But as the sailing vessel would be deficient of freight on an 

 average at least 30 tons, the actual loss of freight would 

 be .e.,^ 36 



01' tV 



Allowing for this, the cost of conveying 350 tons of freight in £ 



the steamer would be „ 2600 



And in the sailing vessel. , , 2150 



