August io, 1893] 



NATURE 



357 



finished iron have declined to the extent of 36% since the same 

 date. Instead of finished iron absorbing 40% of the Cleveland 

 pig-iron made as in 1872, in 1891 it absorbed only about 23%. 

 The quantity of ore raised in Cleveland in 1872 was about 

 6,300,000 tons, and the quantity of pig-iron made in the north- 

 east district about 1,920,000 tons. During the year 1891 there 

 were produced in the north-east district 795,487 tons of steel 

 ingots. In the latter year 2,260,000 tons of ores other than 

 Cleveland were smelted and of these about 2,100,000 tons were 

 imported chiefly from Spain. On the whole, there has been 

 produced in this district about 36% more pig-iron than in 187 1. 



It is rash indeed to prophesy in industrial matters, 

 which are influenced by many complex problems, but it would 

 seem that the great change which is impending over Middles- 

 borough is the adoption of a new process in steel making. To 

 bring ore from Spain — the greater part of which is converted 

 into .slag, simply to encumber the ground ; whilst a smaller 

 percentage ultimately finds useful application — seems an arti- 

 ficial proceeding. At first it was forced upon English steel- 

 makers, from the fact that our native ores, with few exceptions, 

 are phosphoric and therefore unfit for the pneumatic process of 

 steel-making. Later discoveries have removed this disability and 

 by the basic process phosphorus can be eliminated, and good 

 steel made. The Cleveland district is richer in iron ore of high 

 quality than any other in England, but this ore is not suitable 

 for steel-making by the old acid process. It is therefore the 

 manifest duty of Cleveland to foster and perfect the basic 

 system of steel-making, and so use the phosphoric ores of her 

 native hills. The problem is chiefly a commercial one. Happily 

 the stagnation of trade will quicken the ingenuity and enter- 

 prise of steel-makers, and we shall no longer depend so fully on 

 a foreign source for the raw material of the most important 

 industry in the kingdom. 



The discussion on Mr. Head's paper turned chiefly on the 

 respective merits of Yorkshire iron and mild steel. Mr. 

 Windsor Richards said that best Yorkshire iron was better than 

 the best mild steel made. The statement is too sweeping, and 

 those who use this material will be more likely to agree with 

 Dr. White, the Director of Naval Construction, who spoke in 

 praise of mild steel, laying emphasis on the lower price it costs 

 compared to Yorkshire iron. Mr. Aspinall, the chief Loco- 

 motive Engineer to the Sheffield, Manchester, and Lincoln 

 Railway, and one of the best mechanical engineers in the 

 country, also spoke strongly in favour of steel, traversing Mr. 

 Windsor Richards's statement that the mildest descriptions 

 could not be case-hardened. The subject, however, is some- 

 what antiquated, and were it not for the high authority of Mr. 

 Windsor Richards, would hardly be worth reopening. The 

 difficulties that stood in the way of steel for engineering pur- 

 poses have been overcome years ago. 



The next paper on the list was a contribution by Mr. Richard 

 Grigg, and dealt with the newest industry of Middlesborough, 

 namely, that of salt manufacture. The late John Vaughan, 

 boring for water, came upon salt, and the result has been that 

 quite a brisk industry has sprung up. At first the wells were 

 made by the diamond drill, but the process was so expensive 

 that the industry would have been strangled in its birth, had it 

 not been that American ingenuity came to its aid. The salt in 

 the Middlesborough district is at a considerable depth below 

 the surface; in some places 1700 feet. The strata that have 

 to be bored through are difficult, and it was thought at one 

 time that the salt was too deep to win with profit. Some 

 shrewd person, who had travelled in Pennsylvania, remembered 

 how the Americans make their oil wells, and the system has 

 been transplanted to Middlesborough, so that in some parts one 

 might also fancy one's self in the neighbourhood of Pittsburg, so 

 closely have the characteristic timber derricks been copied in 

 this heart of the iron country. The chief point of interest 

 raised by Mr. Griggs's paper was whether the brine-pumping is 

 going to lead to subsidence or not. On the other side of our 

 island, in the salt districts of Cheshire, brine-pumping has led 

 to most curious and, to those on the surface, unpleasant re- 

 sults. The houses in Northwich bear evidence of this; the 

 house-line presents most devious and irregular courses; the 

 ' houses themselves are iron strapped or wooden bound, so that 

 ithey may be "jacked" to lift them, as the earth upon which 

 'they stand subsides, and it is no uncommon thing for a North- 

 wich landlord to be called on to the rescue of his buildings, 

 which are in process of disappearing beneath the surface. In 

 lone place a house has so far settled down that what was the 



NO. I 24 I, VOL. 48] 



first-floor bed-room has become the basement, and the front 

 door has been cut off between the two upstairs bed-room 

 windows. Northwich Bridge has been lifted several times, or 

 it would have been transformed into a dam ; whilst large tracts of 

 land have subsided bodily, and in one place there is, or used 

 shortly ago to be, a line of rails which ended abruptly at the 

 edge of a cliff, the remaining part being on a plain beneath. 

 At one time these rails were continuous, and were only broken 

 through subsidence caused by the abstraction of salt beneath. 

 Probably, however, Middlesborough will not be served in this 

 way. The salt there is deeper, and is surmounted by a stratum 

 of rock. As the brine-pumping goes on, and large cavities are 

 formed by the abstraction of salt, the roof of rock is left unsup- 

 ported. The superincumbent mass of earth may, or may not, 

 Ijreak this down. It is hoped that should a fall of the rock take 

 place, the pieces descending will form themselves into a dome 

 shape, and, therefore, be well calculated to resist the weight 

 above. The hope appears too sanguine, for the rock would be 

 more likely to give way over the centre of the cavity than at the 

 sides, where it is nearer the supporting salt not dissolved; in- 

 deed, the dome would more likely be an inverted one. In the 

 Cheshire district we believe the subsidences have invariably 

 been of a gradual nature, so that inconvenience rather than 

 danger has been the result. In Middlesborough the results may 

 not be of the same gentle kind. It is true that the cavities are 

 deeper in the earth, and that is an element of safety in one re- 

 spect, but should the stratum of rock below give way suddenly 

 serious results might follow, especially if some of Middles- 

 borough's ponderous furnaces were above the spot affected. 

 Near Nancy, in France, a subsidence of earth took place which 

 was so sudden that it caused a report which was heard 12 miles 

 away. Middlesborough is pumping salt close to the town, and 

 what is, of course, worse, in the near neighbourhood of the 

 docks. Authorities, however, differ as to what will be the re- 

 sult ; time alone will prove ; it may be in a manner more con- 

 vincing than pleasant. Mr. Griggs's paper contains an excellent 

 description of the machinery used, and illustrations of the same 

 were exhibited on the walls of the Town Hall, where the 

 meeting was held. 



A paper by Mr. A. L. Steavenson, entitled, " Description of 

 the Electric Rock-Drilling Machinery at the Carlin How Iron- 

 stone Mines in Cleveland," was next read. After briefly refer- 

 ring to the various means of drilling holes for blasting pur- 

 poses, the author proceeded to describe the electric drill. We 

 could not give a description of this without the illustrations 

 which were exhibited on the walls. Mr. .Steavenson, who is a 

 mining engineer, has tried all kinds of drilling — hand, com- 

 pressed air, hydraulic, and petroleum engine, but he gives pre- 

 ference to electricity as a means for transmission of power in 

 this work, although he says that petroleum engines have done 

 good work. 



The last paper read at the meeting was a contribution by Mr. 

 George J. Clarke, engineer to the Tees Conservancy. In this 

 he describes briefly some of the works which have been done 

 in making the harbour at Teesmouth and improving the navi- 

 gation. Dredgers, training-walls, and breakwaters have been 

 combined in this work which has proved of such signal value 

 to the district ; in fact they have made its large commerce 

 possible. 



During the meeting a number of excursions to various iron- 

 works were made, and members had an opportunity of seeing 

 the colossal proportions to which the machinery for the pro- 

 duction of iron and steel has been carried in the present day. 



THE WILLIAMS COLLECTION OF MINERALS. 



A FEW words relative to the collection of minerals which has 

 •^ just been distributed among various museums by Mr. J. C. 

 Williams, M.P. for the Truro Division of Cornwall, will be of 

 general interest. This collection had been gradually brought to- 

 gether by the father and grandfather of Mr. Williams ; it was 

 removed nearly thirty years ago from Scorrier, where Mr. 

 Michael Williams formerly lived, to Caerhays Castle, nine miles 

 from the nearest railway station (St. Austell), and it has since 

 been too remote from the ordinary line of travel to be of easy 

 access to visitors. It was in this collection, while it was still at 

 Scorrier, that my predecessor. Prof. Maskelyne, F.K.S., noticed 

 in 1863 the specimen of connellite from which it seemed to him 



