coal gas works at Glasgow, Liverpool, Sheffield, Leeds, Leices ter, Belfast, as well as London, and many other large commer cial and manufacturing towns, as well as small ones, in Great Britain, will use coal gas, and some of them oil gas too, and the people will be greatly benefited by them. I see no good reason that they should not both do extremely well, though some scientific, not practical men, may try to make us believe, that one or the other is good for nothing. I see they are both good, and there is plenty of room for both in this great manufacturing country. I shall recommend to my employers to begin with oil gas, because it is the best; and oil being cheap, and coals dear, it will be the cheapest, and will not cost nearly so much to begin with as coal gas, and we shall require fewer hands to carry it on. I can more easily manage it. When I can get coals as cheaply as they do at Sheffield, and some other places, I may make coal gas too. Besides, I need not lay down pipes more than one-third as large as for coal gas, and this is a great saving; so we shall all save by it. You ask me to tell you how much oil gas costs, and how much profit may be made by it. I cannot tell you any thing about that till I have erected works, and made some oil gas, and see how many people use it, and what they will pay for it. I have given you more opinions already than some may think correct. If they desire to possess more information, I would advise them to travel as I have done, and inquire of every one they can find to tell them; and I am certain they will eventually acquire it. I think the gas-lighting system in its infancy even in this country; and to learn all about it, you must see all engaged in it. I have not seen half of them, but must go home and do the best I can. You desire me to state what quantity of gas can be obtained from different kinds of coal. This depends so much on the manner in which it is worked, that if I give an opinion some will say it is too high, and others too low. At Liverpool, I think, Mr. King says he finds it good economy to obtain only about 7000 cubic feet from a ton. He uses the Wigan Orral coal. At Glasgow, they obtain from their rich candle coal 12,000 feet. This coal is called candle coal, because the people formerly (and now too for what I know), used it instead of candles. They make the best gas I have seen, always excepting that procured from the decomposition of oil. Mr. Peckston has given a very good table of the different kinds of coal in the kingdom, and the quantity of gas to be obtained from each; and had he seen as much of oil gas as I have, I think he would have given a better account of that than he has. To give my opinion regarding retorts, I think those used by Mr. King, and invented by him, the best I have seen for a large work. They are large, wide, and flat, shaped something like a D, turned half over to the left. They are made of rolled iron, and rivetted. Those at Glasgow are much smaller, of cast-iron, and nearly of the same shape. Mr. George Lowe, manager of the Brick-lane and Dorset-street stations, in London, uses similar ones, and finds them answer better than the round ones. The former are both theoretically and practically the best. The coal is more equally and more speedily carbonized. The fire comes more readily in contact with every part. The thinner the coal is in the retorts the better. Perhaps you will I have seen many more gas works than I have mentioned: true, and there are many who understand them better than I do. When I get home, and find I know enough to construct a work which shall answer our purposes, and the people like the gas, and use it, and pay as fairly for it, then I may send you another article, but not so long as this. say At Paris, I examined their coal gas works, and one oil gas work. Here I met with the most frank and gratifying treatment from Messrs. Say, Thenard, and Darcier, who interested themselves to procure me admission to the gas works; the managers of which showed me every thing, and treated me equally well. Gas works in Paris will long have to contend against the best lamps and purest oil I have seen. Light is not used nearly so late in Paris, except in the coffee-houses, as in England, which is a great drawback on this kind of industry. The oil gas here is obtained from oleaginous seeds, principally from the colza and hempseed; the quantity great, but the illuminating power not quite half (as nearly as I could determine by a few experiments), that from fish oil. It is not so offensive as coal or oil gas. I think this work will be profitable. One coal gas work may be profitable too. I understand that the largest is to be removed beyond the walls of the city. They have a gasometer which may contain_256,000 feet of gas, and a removal will destroy the concern. I believe many people are taught that such a large gasometer is dangerous. I do not think there is much fear of a gasometer's exploding. Some trifling explosions may occur in confined places, but they will never injure any body. They are not half so dangerous as most mechanical employments, or a windmill, which no one is afraid of. I have not volunteered these opinions, or stated facts to serve any separate interest. Both systems can be successfully prosecuted, and that to be preferred must depend on so many local and contingent circumstances, that every one must judge for himself. My business was to acquire correct information on this interesting subject to enable me to give my employers the means of judging which system would best answer our particular situation; and as they had given me power to act for them to a certain extent, I have decided as above stated. I have been much longer absent than they expected; and I fear am not so well informed as they could wish. I am happy to say that the statements made to me by Messrs. Taylor and Martineau, respecting the consumption and illuminating power of oil gas, have been verified by the experiments they enabled me to make. Were gas works now to be erected to produce the same quantity of gas that is used, I think that nearly one-half the amount expended might be saved; such has been the progress of improvement, and that principally in simplifying the works. I am most respectfully, your obedient servant, ARTICLE II. General Conclusions of an Inquiry into the Era when Brass was used in Purposes to which Iron is now applied. By the Rev. John Hodgson, Secretary of the Society of Antiquaries of Newcastle upon Tyne.* General Conclusions respecting Iron. 1. Meteoric stones, consisting principally of iron in a malleaole state, probably led mankind to the discovery of iron from its ores. To this day large balls of iron stone found in certain parts of Sicily, are called thunderbolts, a name they have no doubt received from their similarity in substance and shape to the true aërolite.† 2. The Egyptians, in the time of Moses, were well acquainted with the use of iron; and all the agricultural and mechanical implements of the Hebrews, from that age downwards, were of that metal. In the time of David they had it in the greatest plenty, as appears from the account of the immense quantity of it, which he provided for the temple, which his son built. but 3. The Greeks supposed that iron was first discovered by the burning of wood upon Mount Ida, 1438 years before Christ. In the time of Homer and Hesiod it was scarce and valuable the account of the iron money of Lycurgus, and the extracts I have given from Herodotus and other authors, prove, that for more than 400 years before the Christian era, it was plentiful. The account derived from the Poliorcetica Commentaria of Daimachus, and contained under Lacedæmon in Stephanus, gives even the uses to which several kinds of iron were applied in edge tools.‡ * Extracted from an elaborate memoir on the subject in the Archæologia Eliana, or Transactions of the Newcastle Antiquarian Society, Part I. + Some remarks explanatory of this passage of Mr. Hodgson's paper, will be found under the head "Scientific Intelligence," &c. in the present number of the Annals. "Different sorts of steel are produced amongst the Chalybes, in Sinope, Lydia, and Laconia. That of Sinope and the Chalybians is used in smith's and carpenter's tools; that of Laconia in files, drilis for iron, stamps, and mason's tools; and the Lydian sort is manufactured into files, sabres, razors, and knives." (See Bochart's Phaleg. p 208.) Daimachus, of Platæa, lived before the time of Strabo. Plutarch has copied a very interesting account of a meteor that threw down stones, from a treatise, which this author left concerning religion. He also wrote something respecting India. See Solon and Publicola compared; the Life of Lysander, &c. 4. When Cæsar landed in Britain, all the nations of Europe enjoyed the advantages which arise from the use of steel; and the Britons had iron works of their own. It is probable too that the Egyptians or Phoenicians had made mercantile voyages to their country, more than sixteen centuries before that time. That it was known to the Phoenicians in the time of Homer, his accounts of amber and tin are unquestionable evidence. And there can be no doubt, but that the Greeks and Romans frequented it commonly ever after the destruction of Carthage, if not sooner: Pliny indeed says, this country was in his time, "Clara Græcis nostrisque monumentis," and he wrote before the Romans were extensively settled in the country.* And besides their knowledge of iron, and their long intercourse with foreign and civilized nations, their old established tin trade is a proof that they had been accustomed to work in mines for numerous ages; and there is no account that implements of bronze are more abundantly found in the old mines and rubbish heaps of the tin districts, than in those parts of the country which are destitute of all sorts of mines. 5. If xoaanσis conpes signify welding of iron, then we have a proof that malleable iron was in use at the time of Alyattes, king of Lydia. Perhaps the different sorts of iron which Pliny calls Stricture, received their name from their being malleable, "a stringendo acie," from, binding the edge, i. e. from having the property of welding, "quod non in aliis metallis." The sentence, mollior complexus (i. e. ferri) in nostro orbe," probably alludes to the same property. But though two pieces of common iron, or a piece of iron and steel, by using siliceous sand, unite at a white heat more readily than two pieces of steel; yet very highly cemented steel may be readily and very perfectly welded by using finely powdered potter's clay instead of sand: and the ancients were acquainted with this process, as appears from Pliny, for in describing the solders used for different sorts of metals he says, "argilla ferro." Conclusions respecting Bronze, Brass, &c. 1. Before the flood, Tubal-Cain (i. e. the possessor of the earth), was "an instructor of every artificer in brass and iron." Plautus, in A. D. 43, was the first of the Romans after Cæsar, who came into Britain as an invader, and Pliny died 35 years after that time. + Alyattes, a king of Lydia, who died 562 years before Christ, made an offering at Delphi of "a silver cup, with a stand for it, made of iron welded together. It was as worthy of observation as any of the things at Delphi. It was the work of Glaucus the Chian who first of all found out the method of welding iron." (opes xάλλnow) "The joinings of this stand were not made with clasps or rivets, but welding was the only fastening. In form it nearly resembles a tower rising from a broader base into a narrow top. Its sides are not wholly continuous, but consist of transverse zones of iron, like the steps in a ladder. Straight and ductile plates of iron diverge from the top of each bar to the extremity." This stand was the only offering, made by the Lydian kings, which remained at Delphi in the time of Pausanias. (Herod, Clio. 25. Pans. Phoc. c. xvi. sec. 1) Does this passage, besides affording us a valuable notice in the history of the useful arts, lead us to some knowledge in antediluvian geography. After the flood, Tubal and Mesech, sons of Japhet, settled on the borders of the Euxine Sea: In Ezekiel's time, their descendants traded to Tyre in " vessels of brass; and by the Greeks were called Tibareni and Moschi. 2. Because Moses mentions metal mirrors and tin, I infer, that the Egyptians, before his time, were acquainted with the use of tin in hardening copper for edge-tools; consequently, that their most ancient arms and mining tools were made of bronze. 3. xaλxos and gold among the Egyptians were first made use of at Thebes, in weapons for destroying wild beasts, and in agricultural implements.* Hyginus, indeed, expressly affirms that Cadmus, the builder of Thebes, discovered as at that place; † and Pliny, that he found mines of gold on Mount Pangaus, and the method of smelting it. We have seen that under the first kings of Egypt, gold mines were worked with tools of xaxxos, on account of the scarcity of iron. In the table of Isis, some of the sceptres or spears have heads which very much resemble our bronze Celts in shape.§ But bronze armour was entirely out of use in Egypt in the time of Psammitichus, 670 years before Christ. 4. Weapons of bronze were partly in use in Palæstine, in the time of David, as I have shown in the account of the armour of Goliah, and of his descendant Ishbi-benob. In Greece, about the same age, they were general, as the extracts I have given out of Homer and Hesiod decidedly prove. Even the rasp with which the cheese was grated into the cup of wine which Nestor gave to Patroclus, was of that metal. Seven centuries before Christ, arms of bronze were worn by the Carians and Ionians; and when Herodotus wrote his history, the Massagetæ made their battle axes, and the heads of their spears and arrows of bronze; but all sorts of weapons and tools of that metal, were looked upon as antiquities in the days of Agatharcides and Pausanias; excepting in things which pertained to religious matters, in which bronze implements were employed in the heathen temples long after the Christian era. 5. That the ancient inhabitants of Italy, in common with the * Diod. Sic. Re. Antiq. i. 2.-In the early history of Egypt, gold appears to have been applied to the most common purposes. Many of their temples were almost wholly covered with it. A similar profusion of silver was found among the Spaniards, when the Phoenicians first visited Tartessus; and a state of society very much resembling that of the Egyptians in the time of Isis and Osiris (i. e. about 1740 years before Christ) prevailed in Mexico and Peru, when they were first discovered, with respect to gold and silver, the use of bronze tools and weapons, the state of statuary, and especially in the use of hieroglyphics. + Fab. 247. Lib. vii. 56. § See Pignorius' Mens, Isiacæ Expositio, fol, 11, &c. Ed. Venet. 1695. Il. xi. 639, |