30 



ON TUB METHOD ADOPTED TO COMPOUND 



tide in lier favoui', tlic indicated horse power being 1,239'2, 

 which gives a coofficiont of 190' 7. 



Kow, taking the mean indicated horse power at 1,269, and 

 disphacement 1,172 tons, corresponding to hor original trial 

 draft of 9 ft. 3 in., and using the original displacement coeffi- 

 cient, 193, you will find that her speed, if referred to these 

 original conditions, would be 13'4 knots, against 14-^'^^ knots 

 formerly. So that with 336 less indicated horse power we 

 lose just three-fourths of a knot in speed ; or in other words, 

 it tiilvcs 336 indicated hoi'se power to got, the last thrce- 

 fonrths of a knot out of her under those conditions, or about 

 one-fifth of the whole power. 



Now, in conclusion, when I am able to say that the pre- 

 sent average consumption of coal per voyage is 49 tons, aa 

 against 92 tons formerly, I think you will agree witli mo 

 that, notwithstanding the loss of speed, which fortunately 

 could bo spared, this di'awback, if it may be so called, is 

 fully compensated for by the enormous reduction in the 

 consumption. 15 ut the whole of the saving in the working 

 expenses does not lie in the reduced consumption alone; for 

 in consequence of only having six furnaces to fire, instead 

 of sixteen, she requires five loss firemen than before, which 

 with other incidental savings brings the total reduction of 

 engine-room working expenses to close on 42 per cent, per 

 annum, and this without impairing the vessel's elliciency for 

 the trade in which she is employed. 



It is interesting hero to note that when working with 

 a jet condenser the consumption per voyage was 92 tons ; 

 when working with a surface condenser the consumption per 

 voyage was 84 1- tons ; and when compounded the consump- 

 tion per voyage was 49 tons ; — a saving of 46| per cent, over 

 the jet condenser arrangement, and 42 per cent, over the 

 surface condenser arrangement. I must confess the actual 



