248 Original Articles. [ April, 
obviously constitute the difference between a commercial failure and a 
pecuniary success, that it appears hardly necessary for us to enter into 
minute details. It is easy to calculate that with her screw alone at 
work, the 12,000 tons of coals which she carried would nearly sufiice 
for a 70 days’ voyage, but the most striking and at the same time familiar 
mode of exhibiting the enormous advantages which she would thus 
possess over any existing transatlantic paddle boat, will be to compare 
her, under her new conditions, with the ‘ Persia,’ showing the relative 
consumption of fuel and the carrying capacity of each steamer. 
With her paddle engines removed, the ‘Great Eastern’ would 
carry about 7,400 tons of measurement goods, and 12,000 tons of coal 
(more cargo and less coal in proportion). She would burn about 200 
tons of coal per diem, and steam 9 knots per hour. The ‘ Persia’ 
carries 1,257 tons of measurement goods, and 1,700 tons of coal, and, 
burning about 150 tons per day, attains an average speed of 12 knots 
per hour. Thus, if we were to take into consideration the increased 
speed attained by the ‘Persia’ over the ‘Great Eastern,’ we should 
have to take the quasi-consumption of the latter, not at 200, but at 
260 tons per day.* 
Now let us compare the work as it would be performed by the two 
boats, with the coal required by each, and we shall find that,— 
The ‘ Perst,’ carrying 1,257 tons of goods, and consuming 150 
tons coal per day, burns 270 ibs. of coal per day for every 
ton of goods carried by her. 
Whilst the ‘Great Eastern,’ carrying 7,400 tons of goods, and 
consuming 268 tons of coal per day, would only burn 81 Ibs. 
of coal per day for every ton of goods carried. 
This comparative statement exhibits in a general manner how great 
is the advantage of a screw over a paddle steamer for trading purposes, 
but as far as the ‘ Great Eastern’ is concerned, we do not hesitate to say 
that with appropriate internal arrangements she could be made to carry 
at least 10,000 tons of measurement goods; that with the screw alone 
and a suitable rig, she would, in an average state of the weather, attain 
a speed of 10 knots an hour; whilst with a good wind she would keep 
pace with, if not outstrip, the fastest paddle steamer afloat. A compa- 
rison of the transatlantic mail paddle boats, supported by a subsidy, 
with the screw boats in the same service not so endowed, would further 
confirm the statement of the superior economy of the screw. 
Once more, too, we would repeat that, instead of believing. with 
many, that her designer and builder have exceeded the legitimate 
dimensions of a manageable steam-vessel, we hold that not a few of 
* Throughout this paper we have avoided technical details which might be 
obscure to the general reader; but we think it right here to say, that im this com- 
parison between the ‘Great Eastern,’ without paddle engines, and the ‘Persia,’ 
we have duly considered the difference between an increase of cargo and the 
weight of the engines removed; also the bearing of the greater size and weight 
of the ‘Great Eastern,’ in relation to her locomotive power ; the ‘‘ lively” nature 
of cargo, compared with the dead weight of the engines removed; and the 
antagonistic action between paddle and screw ; but we have only given our deduc- 
tions in general terms. 
