This is notorious as a monster failure, even with a charge of powder amounting to only one half what the projector fondly hoped would be perfectly harmless in its effects. This Brobdignagian toy has proved to be fearfully expensive, the cost having been estimated at eight thousand pounds. It has, I believe, been the largest and most expensive experiment indulged in by the noble “projector,”[6] and I sincerely hope it will be the last.
[6] Lord Palmerston.
The preceding pages will have done much to remove from an unbiassed mind any favourable impression of the advantages expected to result from the use of wrought-iron cannon. The knowledge of this subject, even among talented and scientific men, appears to be at a very low ebb, as is evinced by the multitude of failures that have taken place; not one success of any moment has as yet been attained, and not a discovery has been made worthy of being chronicled.
Having enlarged thus much on the qualities of a metal which it is certain can never supersede the use of cast-iron, even though it be freed from the defects found practically to exist in our present constructed iron artillery; and having also alluded to the fact that the form has much influence on the durability of cast-iron guns, I now proceed to the more important point of the qualities of cast-iron itself.
Little doubt exists that guns cast a hundred years ago were more durable than those of more recent formation; it is evident, therefore, that apart from mere form, some material depreciation must have taken place in the quality of the metal. The use of hot blast-furnaces, better fluxes, and improved chemical knowledge in the reduction of metallic ores, though highly profitable in a commercial point of view, doubling the products of our mines, and enriching their proprietors, has, unfortunately rendered English cast-iron perfectly unfit for the formation of cannon, if increased range and greater strain by high elevation are to be the order of the day.
The durability of Russian cast-iron is unquestionably greater than that manufactured in England. Some cause must exist for this; and the question arises, is the ore superior to ours, or does the superiority of Russian iron depend on their method of smelting? The latter is, we believe, the cause of the superiority of Russian iron; for experiments show that Russian ore, smelted in an English furnace, yields the same kind of cast-iron as is produced from the ore found in England. The inference, therefore, is plain, that the difference in the process of smelting makes all the difference in the quality of the iron.
Two thousand years ago the Romans, or their dependents, smelted iron in the county of Durham: vast accumulations of slag exist there at the present time; and thousands of tons have been beneficially re-smelted by two adjoining iron-works, and a percentage of iron obtained sufficient to prove that the Romans were little indebted to fluxes or hot blasts for the quality of iron they obtained. The Russians cannot boast of these adjuncts any more than the Romans: the old agents, wood and energy, are alone employed in the smelting of their ores; and in the absence of scientific aids, though they obtain a much smaller aggregate quantity of metal, yet it is undoubtedly of a much superior quality. With the Romans, also, the yield was meagre, but the quality was good; now, however, circumstances are reversed, quantity, not quality, being the order of the day.
The use of coals instead of wood in the process of smelting has introduced a mixture which is very prejudicial. Most of the coal, even from our very best mines, contains a large quantity of pyrites, or bisulphuret of iron, which, combining with the cast-iron, injures it to an incalculable extent.
These facts fully explain why our cast-iron guns are not so good now as formerly. Select the most suitable mine in the kingdom, erect a furnace on the most improved principles, employ wood fuel only, avoid fluxes and hot and cold blasts, and be content with the small amount of metal produced, and beyond all doubt the quality will be all that the most sanguine founder or artillerist could wish.