of this noble undertaking, that his name will derive new honour from its permanent connexion with productions which justly add to the scientific reputation of his country. Our mine agents, and their employers, must have recourse to documents like these, -they are the book of Nature rendered intelligible to every reader; and no person having to deal with the facts they present can henceforth be excused, if he does not make himself acquainted with them. Iron Ore. Although Iron, in the form of an impure carbonate, (the mine' of the colliers), is very generally found to occur in coal districts, its presence is not universal, and it begins to be scarce both in America and in this country. It may, therefore, be worth while to examine again some of our neglected coaltracts, with a view to the discovery of this valuable ore; since, although now deficient in coal, they may still contain the mine. In this view the wealds of Kent, Sussex, and Hampshire, might, perhaps, repay an attentive examination-iron having formerly been manufactured in considerable quantities in those counties, and ore of excellent quality existing there in greater abundance than has generally been suspected. We know that the opinion of some manufacturers of experience in the iron trade is in favour of such an inquiry; which could be made with ease on the coasts of Sussex and of the Isle of Wight, as well as in the interior. If the ore were found in the counties above mentioned, the consumption of fuel in the manufacture of iron has been so much reduced by recent improvements, that it would probably be less expensive to bring coal to the country supplying ore, than to take the ore to the coal districts. It is not familiarly known that the representative of our Wealden,' (which is in England an unproductive coal formation,) affords excellent coal in the North of Germany, and supplies the manufactories of Hanover and other places. Temperature of Mines.-It was ascertained by Prof. H. D. Rogers, from observation in the mines of Eastern Virginia, that the temperature augmented at the rate of 1° of Fahrenheit for every 60 feet of depth, from the invariable plane' downwards. (Reports of Association of American Geologists, 1843, p. 533.) And Professor T. Phillips deduced the very same rate of increase, from his own observations, in the mine at Monk Wearmouth, in Durham, nearly 1600 feet deep. (Philos. Magazine, Dec. 1844.) Steam Navigation in the Pacific. —Among the places of interest connected with this subject, Australia, New Zealand, Tahiti, the Sandwich Islands, Vancouver's Island, and Kergue len's Land, are among the most prominent; and under each of these heads the author has given such information as he could collect: we shall mention, however, one or two points, upon which we have recently been favoured with information, correcting or modifying some of his statements. New South Wales. - The total extent of the coal tract in the vicinity of Newcastle, Port Hunter, has not been ascertained; but the sales by the Australian Agricultural Company in 1840 amounted to 20,000 tons. In 1845 the Company had usually 10,000 tons ready on hand, the price being 11s. per ton delivered at the works, and at Sidney 22s. per ton. The sales in 1847 amounted to 40,000 tons. The monopoly by the Company having been surrendered in 1847, several works have since been opened by private speculators; and a seam of ten feet in thickness has recently been discovered within two miles of the place of shipment, so that the Company are now enabled to meet a demand of 300 or 400 tons per day, if required. There is no reason, therefore, to apprehend any deficiency of supply for the use of steamers upon this coast; and it is even supposed that the copper of South Australia might be smelted near Port Hunter with advantage-as vessels of 3 or 400 tons can lie in the port of Newcastle in perfect safety, under the end of the coal slips. Van Diemen's Land-Count de Strzelecki, in his valuable work, showed the existence in this island of two deposits of coal,-1. the South Esk Basin, supposed to agree in character with the Newcastle Basin of New South Wales; 2. the Jerusalem Basin, not far from Hobart Town on the east, which is said to afford anthracite; 3. in addition to these deposits previously made known, excellent coal is reported to have been recently discovered at Schouten Island on the east coast of Van Diemen's Land.t New Zealand. The extracts with which we have been favoured from official documents prove that coal has been found in so many places on the coast of the Middle Island, or New Munster, that the existence of some important coal-fields there seems to be far from improbable. The quality of the coal first obtained is of small importance, as it seldom happens that specimens near the surface are in such condition as fairly to represent the seams. A list of such names of places as we could find upon *Physical Description of New South Wales and Van Diemen's 'Land.' 8vo., 1845. It is mentioned in a dispatch from the Governor to the Home Office, Nov. 6. 1848, printed in Parliamentary Papers, May 25. 1849. * the map is subjoined. Two of the places in which the coal is stated to have been most abundant are in the vicinity of Massacre Bay and of Otago. But in the hills near Wanganui, on the west coast of the North Island, or New Ulster, one very thick bed has been seen. So much money has been wasted by injudicious attempts at mining, and so much mischief done by the accumulation of water in deserted and unknown works, that it may deserve consideration whether it would not be expedient to introduce at once in the incipient stage of coal mining in this colony, some system by which a registration of maps and sections of coal mines should be ensured, and some control by proper inspection retained over the works. This will become especially necessary, if, as is not improbable, the natives be employed in mining;-in which case the well-known dangers of coal mines would be still more formidable, to them and to their employers. No part of this volume has given us more satisfaction, and does more honour to the author, than that which relates to the The Map here referred to is that of 'The Diocese of New Zea'land,' connected with Bishop Selwyn's 'Letters and Visitation 'Journal.' 3d edition: 1847. I. MIDDLE ISLAND (or New Munster). East Coast:-1. Lookers-on Bay, or Kaikora. 2. Vicinity of Port Otago; skirts of the Saddle Hill, and within a mile of the navigable river Taieri; Coal Point. 3. Matou, Molyneux, or Clutha river. 6 West Coast:4. Milford Haven, coal exceedingly abundant, and limestone.' 5. Bluff Point (or Bold Head). 6. (South) Wanganui Harbour and Cape Farewell,-' very large 'beds of coal.' North Coast:-7. Massacre (or Coal) Bay,-'coal crops out every where on the beach of the Promontory at Iamauini' (quare exact site?); Motupipi River-coal abundant;' Tata and Taupo, near Separation Point (between Massacre and Blind Bays). II. SOUTH ISLAND: Stewart's Island (or New Leinster): 8. Port William,-'coal very abundant.' 9. Port Mason, or Fenouacho Inlet. III. NORTH ISLAND (or New Ulster): West Coast: : 10. Hills between Wanganui and Ahuriri. 11. New Plymouth,—' suburban section close to the town.' 12. Mokau, about forty miles north of New Plymouth. East Coast: ·- 13. Lignite is said to abound in the frith of the Thames River.] condition of coal miners and their families, the accidents and maladies to which their occupation is exposed. The explosions of gas in collieries, which form one section of this subject, are so dreadful, both in their immediate effects and their consequences, and they have, of late especially, been so frequent in the British mines, that we shall devote the remaining pages which we have at our disposal, to the consideration of the means of obviating them. - The miner is a quarryman, who, in addition to the wants which are incident to all hard labour on the surface, must be supplied with light and fresh air by artificial means. And, besides the ordinary sources of danger, the collier is exposed to instant death from explosions of the inflammable gas which issues from the walls and roof of the caverns that surround him on every side; or, if he survives the stroke of that dreadful power, which burns by its flame, as well as poisons those who respire it, he is often suffocated by the carbonic acid and other gases produced or left by the explosion. Both the coal itself, and the adjacent strata, give out continually — and, in some mines, in great quantity that fatal gas, one part of which diffused in eight of atmospheric air, renders the whole powerfully explosive; and, the heat thus evolved, again acting on the coal, a train of explosions, progressively increasing, is produced, of such force as to bear down all resistance. The following statement, given by Mr. Taylor from Burat*, a French geologist and miner, tells the results: The chemical effects are the direct production of the vapours of water and carbonic acid, and the separation of azote. The physical effects, a violent dilatation of gas and of the surrounding air, followed by a re-action through contraction. The workmen who are exposed to this explosive atmosphere are burned, and the fire is even communicated to the wood and to the coal. The force of the wind produced by the explosion is so great, that even at considerable distances from the site, the labourers are thrown down, or dashed against the sides of the excavations; the walls, the timbering, are shaken, broken, and crushed, — they fall in. And these effects extend even to the mouths of the pits, from which fragments of wood and stone are projected with a thick tempest of coal in the form of dust. But the evil does not rest there vast quantities of carbonic acid and azote, produced by the combustion of the gas, become stationary in the works; and those who may have escaped the immediate action of the explosion perish by suffocation. The ventilating currents of the mine, suddenly arrested by this disturbance, are now much more difficult to re-establish, because the doors which served to regulate them are partly destroyed. The fires are extinguished, and often the par * Géologie Appliquée,' &c., 2me édition :-Paris, 1846. titions fixed at the mouths of the shafts to regulate the course of the air are damaged and displaced to such an extent, that it becomes impossible to convey any help to the bottom of the works.' (P. vii.) The British collieries appear to suffer especially, from explosions; and, so far as natural causes are concerned, they cannot be expected to be less frequent in future; for, as the demand for coal increases, our most valuable seams must be followed down to greater depths from the surface. Nor can our Government, as in many of the continental states, take a lead in the reformation of our mines, which are here the private property of individuals. Nevertheless, it is here, we are satisfied,- in England, and in our Parliament,-that the battle must be fought with this Demon of the mine, and with that still more formidable spirit with which he seems too often to have allied himself the love of gain. -- Looking, therefore, to the probability that measures will, at last, be brought before Parliament early in the next session, we shall briefly make known to our readers some of the points at issue; for we believe, most sincerely, that many of the lives destroyed in our coal mines, during the last ten years, might have been saved, if the measures pressed on the attention of Parliament had been judiciously acted upon. We are convinced that at this moment the general feeling of the country is directed to this subject with peculiar interest. 1. As any portion of the gas, with from about five to fifteen portions of atmospheric air, forms an explosive compound, danger must always be apprehended where only a limited quantity of the latter can be introduced into a mine. If we could open out the mine to the atmosphere, and convert it into an ordinary quarry, the gas, from its lightness, would immediately ascend, and all danger would disappear. And although this most perfect ventilation is unfortunately impracticable, we should endeavour to approach it, in the ventilation of our mines, by the largest possible dilution of the noxious gas. 2. This dilution, and airing of the mine, by large supplies of air fresh from the atmosphere, is not less necessary to the health of the workman, than for the prevention of explosion, and the safety of his life. Men cannot breathe, in an atmosphere containing one sixth of the gas, without great injury to their health. 3. The Shafts, then, are intended-first, to give the workmen air to breathe; and, secondly, when the mine is dangerous, to make it unexplosive, and to expel the gas.* * Ventilation is necessary also in deep mines to cool the air. The mean temperature increases with the depth at the rate of 5° for every 300 feet; so that in a mine of 1200 feet, the mean temperature |