Iron has been cited in Deuteronomy as the essential and last fruit of the promised land. Our interiors, as halls and churches, will assume new development and grandeur by iron, since we have seen 200 feet span at Birmingham without abutment, and 150 feet at Paris in still more enduring structure. The Pantheon of Rome, Sta. Sophia, St. Peter’s, the Baths, and the great Riding-house at Moscow, will hide their glories; and iron will henceforward dispense with pillars and clerestory, flying buttresses and abutments, and roof our churches in bold and single spans. With all due reverence for antiquity and precedent, we ought to open our eyes to the reconciliation of this new material and its peculiar faculties with the laws of proportion and taste; and this is a problem worthy of the best spirits, both as to the form of roofs or ceilings, and the form of supports, which, in iron, with 1-40th part of substance of stone, will give equal strength of support.
Iron may be termed the osteology of building. Hitherto the architectural system has proceeded on statics and equipoise of molecules, as if the human frame were built without bones. Now our buildings will have bones, giving unity and strength which never before existed. The nervures of the Gothic will now be in uniform and single arcs, erected at once: the library at St. Généviève, by Mons. Arbruste, exhibits an experiment in this way.
Concrete, not new.
Professor Cockerell observes:—Concrete is a novelty characteristic of the nineteenth century, or rather a resuscitation of ancient practice, as shown by quoting Philibert de l’Orme; but in the bridge of Alma, at Paris, concrete has taken a new and admirable development, where three arches of about 140 feet span are cast on the centreing, forming one vast stone from pier to pier. The only voussoirs used are in the face of the arches. A peculiar cement and hard fragmented stone has effected this with vast economy of cost and time, and promises well. The so-called Temple of Peace at Rome is ceiled and vaulted with a similar concrete. The coffering was previously moulded in all its detail upon the centreing, and then covered with grosser concrete, so that on removal of centreing all was finished. A vast fragment now lies in the middle of the Temple, and at Tivoli we find that Adrian employed the same simple process.
Sheathing Ships with Copper.
From an old pamphlet we learn that:—“Mr. Pepys, a scientific man, in the reign of Charles the Second, suggested the great importance of Sheathing Ships with Copper, and urged the advantages with sound and persuasive arguments; and says, in some despair, ‘I wish it were tried on one ship.’ But this experiment was delayed for nearly a century; and when it was tried, although it answered beyond expectation, yet the prejudice against innovation was so strong, that in Admiral Keppel’s fleet, 1778, there was only one coppered ship.”
Copper-smelting.
A prodigious quantity of copper is obtained from Lake Superior. Mr. Petherick, the well-known mining engineer, informed Dr. Percy that at Minnesota, in 1854, not fewer than forty men were engaged during twelve months in cutting up a single mass of native copper, weighing about 500 tons! The native copper at Lake Superior in some places occurs curiously intermingled, but generally not alloyed, with native silver. The following anecdote is recounted of the value of the gold in the residue from some South American copper-ores, and which was communicated to Dr. Percy by Dr. Lyon Playfair. At certain large chemical works where sulphate of copper was prepared by dissolving copper in sulphuric acid, an insoluble residue was produced in the process, which had been put aside from time to time, and had fortunately not been thrown away. A small sum was offered by certain persons for this residue, which had not previously been regarded as of much value. Suspicion was excited, especially by the quarter from which the offer proceeded, and it was declined; whereupon the residue was examined, and was found to contain 700l.-worth of gold!
Antiquity of Brass.
Dr. Percy, the able metallurgist, extracts from history the remarkable inference that the orichalcum of Cicero, and which closely resembled gold, was really Brass; this alloy of copper and zinc being the only metallic substance which it is possible to conceive the ancients could have so mistaken. The modification of brass which is termed “Muntz’s metal,” has been the subject of one of the most lucrative patents known: when its well-known proprietor died, his property was sworn under 600,000l.