110 REPORT—1846. 
similar construction during 1845, and that the sailing-ships and steam-vessels 
then under construction in that port would require 25,000 tons of plate-iron 
and angle-iron. 
The employment of iron for the purpose last mentioned, that of ship- 
building, has already been an object of very great national importance. The 
extent to which this use for the metal may be carried in future years it is 
not possible to foresee, but we may base upon even our present limited ex- 
perience the hope that by this means our furnaces and forges may be pro- 
vided with some employment when our system of railways shall be completed. 
The tonnage of mercantile shipping belonging to the British empire in 1845 
was 3,714,061 tons, and exceeded the amount in existence in 1814 by 
1,097,096 tons, but during that interval there were built and registered ships 
amounting in their measurement to. 5,476,957 tons, so that there were required 
to be built ships of the aggregate burthen of 4,379,861 tons, in order to re- 
pair the waste occasioned by wear and tear and by losses: altogether the 
building of ships has gone forward at the average rate of 176,676 tons 
yearly. Assuming for the moment that this same rate of building will be 
called for in future years, and that the whole of the mercantile shipping con- 
structed would be built of iron, this would prove a very insufficient substitute 
for the demand now existing for railway purposes. I have before me a 
statement of the weight of iron used in building eight large sea-going steam- 
vessels, the aggregate measurement of which was 5922 tons, by which it is 
shown that the metal used was 2877 tons weight, or 9 cwt. 2 qrs. 24 lbs. for 
each ton of measurement, and at this rate the construction of 176,676 tons of 
shipping in each year would provide a market for no more than 85,814 tons 
of wrought iron, equal to 115,849 tons of pig-iron. We cannot suppose, 
however great may be the advantages attendant upon the substitution of iron 
for timber in ship-building, that this use of the latter material will be all at 
once, or indeed for many years, abandoned. There are many existing inter- 
ests opposed to the change, and there is much of prejudice still to be over- 
come before all our merchant-ships will be built of iron. We must likewise 
bear in mind the now well-established fact, that iron ships are far more durable 
than those built of timber, that they require much less repair, and that they 
are less subject to accident and to loss. It cannot be necessary, however, to 
enlarge upon this subject, since the Association has already been favoured 
by Mr. Fairbairn at one of its former meetings—that held at Glasgow in 
1840—with a valuable paper upon the subject. 
Placing this subject in another point of view, may we not however feel 
justified in believing, that when opposing interests shall have been silenced, 
and existing prejudices shall be overcome, and the fast increasing commerce 
of this country shall have experienced some degree of that development 
which is expected to spring from late changes in our commercial legislation, 
the rate of increase hitherto sufficient to supply the waste of our mercantile 
marine, and to provide what has been necessary for its increase, will no longer 
suffice to that end, and that although our iron ships may outlast by three or 
four times the less durable vessels now constructed, and through all their 
existence may call for little or no materials to be used for their repair, that 
the necessity for additional shipping may in great part prove an equivalent 
for the lessened demand otherwise arising ? 
The building of iron ships is at this time proceeding at a greater rate than 
at any previous moment since their first introduction, although the price of 
iron has so materially advanced, and this should give us the assurance that 
when, as we may expect it will happen, the falling off of railway demand, or 
the exertions of our iron-masters, shall have restored the equilibrium between 
