1842.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



417 



tinent of Europe took place to a very considerable extent, all of u hich were 

 mar.ufacUucd iu this country into bars, sheets, &c. ; and from the circum- 

 stance of these scraps, being all of charcoal iron, the bars, &c.. so made, 

 could not but deserve the good name they acquired and long maintained- 

 Tlie flow of scraps into England has, however, long since ceased, and the ex- 

 portation from this country having become a considerable trade, it follows, 

 of course, that scrap iron now must be made from our own scraps ; and when 

 it is remembered how small a proportion of good iron to bad has for many 

 years been made liere, bars. See. manufactured from them cannot but be of 

 very irregular and dubious quality, hence it is that the best scrap iron cuts 

 so poor a figure when compared with a well made iron from known good 

 minerals. 



The remarks I have made are in reference to irons of known good quality, 

 but I am ready, and have pleasure in admitting that the use of hot air has 

 been of very great advantage at those iron works whose produce had not a 

 first-rate name, by enabling their proprietors to make it at a less cost, without 

 a proportionate deterioration in quality ; and there are some few works 

 whose iron, made with cold blast, was so bad, that any change could not be 

 but for the better. There is also at present a strong impression that iron 

 cannot be made with anthracite coal only, but with hot air, and that iron so 

 made is better than any other. The goodness of its quality is, however, due 

 lo the great purity of that coal. But even here we are told, in a paper read 

 before the Polytechnic Society of Cornwall, by a gentleman of great prac- 

 tical skill, that iron made with such proportions of anthracite coal and coke 

 as enabled him to use cold blast, became much weaker on his using hot air, 

 all other circumstances being the same. 



My apology in troubling you so far must be in the importance of the sub- 

 ject, and the daily increasing importance to society of the strength of that 

 material by which the locomotive power is applied that so rapidly conveys a 

 very large portion of the human race both by land and sea. When we are 

 about to purchase a horse which is to convey ourselves and families at the 

 moderate rate of 8 or 10 miles an hour, with what inherent caution our first 

 object is to examine his knees, to ascertain his safety '. In the steam-engine 

 we are prevented taking this precaution, and yet in travelling three times as 

 fast, our risk is in very much greater proportion. Now in this fast travelling 

 it must not be forgot that in the engines which convey us there are two cy- 

 linders, and at least 280 returns of the piston, and therefore there are 280 

 percussions each minute of 9,2'lOlb. pressure in the power itself, and also the 

 tires of about 42 wheels and axles in each train, passing over a joint of the rails 

 every 5 yards of our journey, the percussions of which are very sensibly felt, 

 with numberless others of minor effect, by which it will be at once seen of 

 what inestimable importance it is that all iron used for such purposes should 

 not only be strong, but be so under percussion ; for I need only remind you 

 that it is more than probable, should any one of the numerou.? parts give 

 way, by any one of the many percussions they have to sustain, that an acci- 

 dent of the most calamitous nature would be the result. 



With this view of the subject I may probably be excused, if I so far further 

 trespass on your patience as at least to endeavour to point out a duty which 

 the public only can perform for itself, namely, to take especial care that the 

 needful protection is given to that class of iron makers whose first care it is 

 to maintain its utmost strength, regardless of the expense of doing so. And 

 in order that it may be understood how far such protection is required, the 

 following statement should be made known. In the year 1830 the total 

 quantity of pig iron made in Great Britain was about 6.53,500 tons. In 1840 

 the make had increased to 1,396,400 tons; and although the stock of pig 

 iron at the latter date was very smill, the price of No. 1 had declined since 

 the use of hot air from 8/. 5s. in 1836, to 51. 5s. per ton in 1812 for cold blast 

 iron ; and from 71. 5s. to 3/. 12s. 6rf. per ton for hot blast iron, ' although the 

 workmen's wages throughout that period were rather higher, which item 

 forms nearly 75 per cent, of the cost, from which circumstance it has been 

 very fairly concluded, that the price of the best pig iron made has been 

 brought down at least 30s. per ton lower than it would otherwise have been 



' 1 have been informed that No. 1 hot blast iron has been delivered in 

 L,?eds for Zl. 2s. Gd. per ton, the average of former years being 9/. lOs. per 

 ton for No. 1 cold blast pig iron. 



by the badness of trade gonerally, had not the use of hot air been intro- 

 duced in its manufacture. 



In addition to the observations I have already made on this subject, I may 

 refer to the price current of the present day, and those who do so will see 

 the price of cold blast pig iron in South Wales stand at 3/. 10s. per ton for 

 No. 1 ; hot blast pig iron in the Clyde, 21. 10s. per ton for No. 1 ; and, upon 

 the whole, it seems this case may now be thus summed up, that — 

 The saving in the make of pig iron by the use of hot blast may per ton. 

 (generally speaking) be . . . . . . £0 12 6 



Deteriorated value of such iron in the general market . 10 



Deteriorated value in the Yorkshire district . . . 12 6 



Deteriorated value of castings made of such iron, in the simple 

 article of railway chairs, as reported to the Institution of 

 Civil F.ngineers, on the 1st day of March last, by one of their 

 own body, of the first eminence, and of very great experience 

 in such matters . . . • • . .400 



Deteriorated value of wrought iron when manufactured from 

 pig iron so made, in the market . . . .600 



Indeed, of the last-named iron, engineers and intelligent manufacturers 

 are agreed, and the experiments I have before referred to, show that 6/. per 

 ton is far too little a deterioration for bar-iron of such a quality, and parti- 

 cularly when we reflect how very much bar (and other) iron has now to do 

 with the personal safety of millions of our fellow-creatures. 

 Barnborough Hail, near Rotherltam. 



SHANNON IMPROVEMENTS. 



Lieut. Col. Harry D. Jones, R. E., Shannon Commissioner, and Thomas 

 Rhodes, Esq. Principal Engineer, were at Killaloe, on the 17th and I8th Octo- 

 ber, to witness the discharge of the river over that part of the weir which 

 has been completed, owing to the active exertions of the contractor, Mr. W. 

 Mackenzie, who has advanced the works at this station so rapidly, that they 

 may be said to be fast approaching completion. 



The weir forms the principal feature of the improvements at this station, 

 having for its objects to modify and regulate the great rise of the annual 

 floods, by giving greater freedom of discharge and making a consequent re- 

 duction in their altitude, at the same time preserving a sufficient depth of 

 water for the navigation. 



The weir, when finished, will be 1100 feet in length, of which 618 feet are 

 now completed. 



All things having been prepared, the dam which excluded the water from 

 the weir while building, was broken about lialf-past 3 o'clock on Tuesday 

 afternoon, under the immediate directions of the Commissioners' engineers, 

 Thomas Rhodes and Thomas Barton, Esqrs. The water having been let into 

 the space above the weir, began to flow over it about 5 o'clock, and though 

 the quantity passing over at present is small, yet the effect was grand. It is 

 calculated that during the flooded seasons there w ill be little more than three 

 feet of water flowing over it, although, in seasons previous to the improve- 

 ments, the floods have risen to a height of nine feet, thus showing a general 

 reduction of si.y feet in the height of the flood waters, and proving with what 

 eflect the hand of science can grapple with this mighty element. 



The above operation has opened the canal from Killaloe to Cussane, which 

 had been closed for some weeks, and the communication is now complete 

 from Limerick to our pierhead. 



No accident of even the slightest description occurred, and the whole went 

 off to the evident satisfaction of all present ; the day being fine, the number 

 of spectators were very considerable. The Lord Bisliop was present at inter- 

 vals during the day, and the spectacle was heightened by the prt-sence of 

 many beautiful ladies, (of whom our gay little town has certainly an unusual 

 share,) together with many of the gentry from the surrounding districts. 



The town and neighbourhood possess great interest, both from its natural 

 beauty and its commercial character. We here see the imprint of the Dublin 

 Steam Company, whose great and liberal exertions in the cause of commerce 

 and navigation, under the masteily guidance of C. W. Williams, Esq., aided 

 by the scientific intelligence of their agent, Joseph Clarke, Esq., and the in- 

 defatigable attention of Captain Tully, keeps the curling volume from the 

 steamers' tube gracefully mixing with the beautiful outline of our mountains, 

 while she bears along the noble Shannon the produce of our lands, our trade 

 and fortune, and connects our interests with the world. 



From the bridge the scene is one of exceeding beauty, and becomes en- 

 hanced by historical recollections, for while we here meet, upon the banks 

 of Shannon, many of Ireland's fairest daughters, we see reflected in the 

 bosom of its waters the beautiful hills where, eight centuries ago, dwelt the 

 bravest and best of her sons— Kinkora's Prince, Clonlarf's hero, the great 

 and virtuous, the immortal Brian ! 



