May 13, 1875J 



NATURE 



29 



a large scale. The most important deposit of this last- 

 named ore was contained in the range of veins occu- 

 pying a length of some thirty miles in Somerset and North 

 Devon, from the Raleigh's Cross westward to near Ilfra- 

 combe. Proceeding next to show the relationship be- 

 tween the oxides, the lecturer exhibited a specimen 

 of ore having the appearance of chalybite or spathic 

 ore, being covered with the large rhombohedral crystals 

 characteristic of that species, but which the presence 

 of the brown streak and of water and the percentage 

 of iron proved to have been turned into brown ore. 

 A fragment from the lodes of the Deerpark in Exmoor, 

 next shown, had also lost its carbonic acid, had acquired 

 oxygen and water, and actually become a dififerent 

 substance. It had been argued that the change com- 

 menced with the formation of the more hydrated species, 

 and passed through successive stages to those with 

 the least amount of water ; but on that point evi- 

 dence was as yet defective. The brown ores were un- 

 doubtedly (for the process might be watched in the 

 workings) formed by another series of changes from 

 pyrites through the sulphate of iron. The crystals of 

 brown ore, in the form of pyrites, were among the best 

 known pseudomorphs, and there were localities which 

 invited the inference that this action had taken place 

 on an important scale. Mr. Smyth, in concluding, 

 said he would not, in the present brief sketch, venture 

 upon the N'exed question of the original deposition of the 

 great northern masses of haematite, although strong 

 aiguments for their having been chalybite might be 

 adduced from the occurrence of limestone fossils turned 

 into red ore. He brought under notice another change 

 of condition among the oxides of iron. It was a signifi- 

 cant fact that magnetite was characteristic of the older 

 formations— of those bodies of rock which had during the 

 longest period of time been exposed to the influences 

 which bring about metamorphosis and change of sub- 

 stance. In the Pcrran lode Small portions of magnetite 

 had been formed among the brown ores near the surface. 

 In some of the Cornish copper lodes specimens of mag- 

 netic ore had occurred which looked very much as if they 

 had been carbonates, and amongst the beautiful red ores 

 •of Siegen small grains of magnetite appeared to testify to 

 a partial change, while there appeared to be sufficient 

 grounds for believing that, in many cases at least, this 

 last change in the degree of oxidation might be produced 

 by the ordinary action of natural causes. 



One of the most interesting papers from a scientific 

 standpoint was that read on Thursday by Sir J. G. N. 

 Alleyne, Bart., " On the estimation of small quantities of 

 Phosphorus in Iron and Steel by Spectrum Analysis." 

 This paper forcibly shows the valuable practical results 

 which may follow from lines of pure scientific research. 

 We shall return to this paper in a future number. 



Mr. Lowthian Bell then read a long account of his visit 

 to mines and ironworks in the United States. He began 

 by saying that in the year 1871, one half of the iron pro- 

 duced in England was exported to foreign countries, and 

 one-fourth of this half was despatched to the United 

 States, in all about 750,000 tons. In the year 1874, how- 

 ever, the States only took 130,000 tons, and it was stated 

 that during the three years the producing power of that 

 country had risen from two-and-a-half miUions to four 

 millions of tons. Mr. Bell entered into considerable 

 details on the subject of methods of transport in the 

 United States. The railway system has grown into 

 dimensions far exceeding those in England, the land of 

 its birth. At the end of 1873 the United States had 

 70,651 miles of road, against only 16,082 miles in England. 

 He calculates that 46,000 acres of timber fall annually 

 to provide fuel for the charcoal furnaces. Less than 200 

 acres of a four-feet seam of coal, in the county of Durham, 

 would produce the same weight of coke as is obtained 

 from 46,000 acres of American forest, Coal is more 



abundant in the United States than in any other part of 

 the world, and all kinds are found. In some places 

 natural gas is used for puddling, re-heating, &c. Of pit- 

 coal itself there are 192,000 square miles, as compared 

 with 8,000 square miles in the United Kingdom ; and 

 Mr. Bell thinks it may be doubted where there is 

 any similar area in the world in which a larger pro- 

 portion of the surface is occupied by coal-bearing 

 strata. From the position which the beds of anthra- 

 cite coal occupy, it would appear as if, after their 

 original formation, an enormous amount of lateral com- 

 pression had been experienced by the districts in which 

 they lie. This force has raised the strata into a succes- 

 sion of waves, as it were, the slopes of which vary from 

 an angle of 20 to 45 degrees, and occasionally descending 

 to a depth of 200 to 250 fathoms or more. In some cases 

 this compressive power has been so great as to have 

 forced one ridge back over its neighbour, to such an 

 extent as to convert what is the floor of the seam in one 

 place into the roof at another, and, from a similar cause, 

 the quantity of coal which has accumulated at the anti- 

 clinal axes of some of these coal undulations is so great 

 as to afford a face of forty to sixty feet, or even more, 

 in thickness. In some cases denudation has carried 

 off not only the sandstones and shales, but a portion 

 of the! coal itself; the bared edge of the seam is 

 found immediately under the alluvial matter of the sur- 

 face. He stated that there is a vast extent of carboni- 

 ferous or mountain limestone in America, frequently 

 very near the pig-iron works. Near Baltimore the 

 shells of oysters, which are found in great abundance 

 at Chesapeake Bay, are used. They contain 95 per 

 cent, of carbonate of lime, and are a very inexpen- 

 sive substitute tor lime itself. The United States 

 contains abundant quantities of iron ore of all kinds 

 except the spathose ore, which is very scarce even in 

 Europe. The ironstone of the liassic and oolitic seams, 

 which furnish about one-third of the pig-iron made in the 

 United Kingdom, seems to be entirely wanting in the 

 States. Mr. Bell described the magnetic iron ore of 

 Lake Champlain, its peculiarities, mode of deposition, 

 &c., its abundance, and its freedom from deleterious in- 

 gredients ; he remarked that the contents of the mines 

 are chiefly obtained by open quarry work. The ore yields 

 something hke 67 per cent, in the Iron Mountain deposit. 

 Mr. Bell, in treating of the blast-furnaces, referred first 

 to the establishments which have been founded for pro- 

 moting scientific training and education, and he spoke 

 very highly of the earnestness and devotion which charac- 

 terises those engaged in the mining and metallurgical 

 industries of the States. 



At Friday's meeting Mr. Bell read a paper on " The 

 Sum of Heat utilised in smelting Cleveland Ironstone." 



Other papers read on Friday were : " A brief account 

 of an Underground Fire in the Wynnstay Colliery, 

 Ruabon, and the measures adopted to extinguish it and 

 to re-enter the workings," by Mr. G. Thomson. The fire 

 became so unmanageable as to necessitate the sealing up 

 of the shafts, after which explosions of gas took place, 

 and the shafts were resealed, and so remained for a period 

 in all of nearly five months. Preparations were then 

 made for re-entering the mines, and this was successfully 

 accomplished, and, after subsequent difficulties of a varied 

 character had been overcome, the colliery resumed opera- 

 tions after a cessation of about seven months, and were 

 now in full work again. The means used to effect the 

 object, and a detailed explanation of all the operations, 

 together with statistics of the temperature, the pressure, 

 and the composition of the gases in the different shafts 

 from time to time, were given in the paper. 



On "The Manufacture of Bessemer Steel in Belgium," 

 by M. Julien Deby, C.E., Brussels, and on " The Howard 

 Boiler," by Mr. David Joy, of Barrow-in-Furness. 



Altogether the meeting has been a satisfactory one. 



