432 REPORT — 1856. 



at sea 200 days per annum, exclusive of harbour dues, lights, and pilotage, 

 which are supposed to be the same for all ships of equal tonnage. 



Next, as to the engine department : — 



The average price of marine condensing engines, as now usually con- 

 structed, may be rated at £50 per nominal horse-power, and in general each 

 horse-power nominal may be expected to work up to 2|- ind. h.p., so that the 

 cost of marine engines may be rated at £20 per ind. h.p. Then, assuming the 

 interest on investment at 5 per cent, per annum on the contract cost, the 

 ujiholding and replacement at 10 per cent., insurance 5 per cent., wages and 

 rations of engineers and stokers at £5 per 100 ind. h.p. per week, consu- 

 mable stores (coal excepted) £2 lOs. per iOO ind. h.p. per week, on these data 

 we shall have the prime cost expenses incidental to the engine department 

 (exclusive of coal), amounting to £7 185. per ind. h.p. per annum, which is 

 9d. per day per ind. h.p. sea-time, assuming the vessel to be at sea 200 days 

 per annum. 



These assumed data of pecuniary charges incidental to steam-ship transport 



service, as applied to mercantile purposes, combined with the mutual relations 



of displacement, power, and speed, which are derivable from the foregoing 



/ V^ D^ \ 

 formula ( : — t-~~ = C l according to the constructive type or locomotive 

 \md. h.p. / 



{pality of the ship, as shown by the coefficient or index number C, enable us 



to make up the prime cost expenses, being the minimum at which goods can 



be conveyed, and which therefore should constitute the base of the estimate 



by which a minimum scale of freight charges should be estimated ; and 



applying these data to the ships A and B, employed on a passage of 3250 



nautical miles, as exemplified in the Supplement to Atherton's ' Steam-ship 



Capability,' 2nd edition, page 78, the minimum scale of freight charges per 



ton of goods, according as the vessels may be powered for a speed of 8, 10, 



or 12 knots per hour, will, on the data referred to, require to be as follows : — 



8 knots. 10 knots. 12 knots. 



ShipA £1 15 7 £2 4 6 £3 4-6 



ShipB 272 398 6 16 3 



The proportions in which goods, according to their respective kinds, may 

 be made to bear freight charges so as to yield the average return per ton 

 weight on the entire cargo, is altogether a matter of commercial discretion 

 and management. The entire cargo must be made to yield the average return 

 per ton weight here set forth. 



Hence it appears that 12 miles speed involves about double the freight cost 

 of the 8 miles speed with the superior ship A, and nearly three times the cost 

 of the 8 miles speed with the ship B, and 12 miles speed with the ship B is 

 about four times as expensive as the 8 miles speed with the ship A. Also, 

 the extra cost to the public at which freight charges are enhanced by the in- 

 ferior type or inferior working condition of ship B, as compared with the ship 

 A, if continuously employed on the passage of 3250 nautical miles, and under 

 the data referred to, assuming the consumption of coal to be at the rate of 

 4 lbs. per ind. h.p. per hour, and according as the steaming speed of both 

 ships may be 8, 10, or 12 knots per hour, is no less than 32 per cent, at 

 8 knots, 56 per cent, at 10 knots, and 111 per cent, at 12 knots. Undoubt- 

 edly, the details of the data on which the foregoing calculations have been 

 based are open to correction, and will greatly depend on their application to 

 special services on considerations immediately connected with such special 

 service, and cannot be generalized ; but, whatever alteration of these data 

 may be applied to the ship A must likewise be applied to B, so that, although 



