Class XXVITX
FIRE-CLAY GAS RETORTS, REFRACTORY BRICKS, Ac.
5S5
Stourbridge (Class XXVII,, 107, p. 772), and Mr. A.Potter, of Newcastle (Class XXVII., 115, p. 773). Thesurface of both these retorts is cracked and undulating.When we consider the high and long-continued tempera-ture to which these objects are exposed, the absolutenecessity of attending to every detail in mixing the clayand moulding the retort will be at once recognised; andthe apparently slight defects of some of those sent forexhibition, require to be noticed as of real importance.Mr. J. Pease (Class I., 12*2, p. 133) is HonourablyMentioned for some fire-bricks of excellent quality ex-hibited by him.
Next to England, the finest specimens of fire-claygoods, on a large scale, are from Belgium, from whichcountry there are three exhibitors of gas retorts. TheJury have awarded a Prize Medal to one of these, Mr. T.Boucher, of llaudour (309, p. 1163’, who has sent awell-made retort, extremely thin, of good structure, andfree from surface iron and cracks. The Jury haveawarded the Medal to this Exhibitor on account of theundoubted superiority which it presents over othersimilar objects from the Continent , and do not enteron any question of priority of manufacture that mayarise, or identity of methods adopted by this and otherExhibitors.
The Jury have awarded Honourable Mention to Mr.A. Smal-Wkkpin*, of Huy, Liege (398, p. 1163), for aneatly-made retort of rather indifferent colour; and alsoto Messrs. B. Pastor and Co., of Ardennes, Namur (395, p. 1163), (granted by Class I. likewise), whoseretort is extremely thin and well made (thickness only2^ inches), but faulty in colour, the foxy appearanceindicating the presence of iron, which cannot fail to actas a flux. Resides the retort, these Exhibitors have sentfire-bricks and lumps, having the same fault in colour,hut very beautiful in point of manipulation.
France has sent only one specimen of fire-clay gasretorts, and that not remarkable for excellence. TheExhibitor is Mr. Pauwkls, of Paris (1382, p. 1242;,who exhibits also an ingenious gas moderator, which doesnot come before the present Jury for consideration. Fire-bricks and vases are sent by Mr. de Boissimox, of Lan-geais (427, p. 1199), an eminent manufacturer on theLoire, who has been already referred to, and has receivedHonourable Mention.
Refractory bricks are sent by two Exhibitors fromPortugal and one from Spain . Of the former, some(275 to 278, p. 1311) from the Manufactory atBuuioens, promise well, but there is no proof of theirexcellence beyond the appearance of the brick. Theyare, however, Honourably Mentioned, aud the Jury alsomention in the same way Mr. Jose Ferreira PintoRasto (Prize Medal in Class XXV.), of Vista Alegre279, p. 1311), who exhibits refractory bricks. Theoury are informed that these bricks are made of a clayalso used for earthenware, and certainly admirablyadapted for the finer works of this kind, and that theExhibitor is the discoverer of this bed, which has beenused for more than a quarter of a century in the porcelainworks at Vista Alegre, now very extensive. Great creditappears to he due to Mr. Pinto for the persevering indus-try with which lie has struggled against numerous dilfi-culties, and succeeded in introducing into his country amost useful and important manufacture. The bricksexhibited are neat, aud appear of good quality. Theycoutain much of what is technically called “ grog ”
(coarse fragments mixed with fine paste), which rendersthem capable of standing a sudden application of heatwithout cracking, but the small extent of the exhibitdoes not justify the Jury in giving more than HonourableMention.
The bricks sent by the Aueencia Company at Madrid (53, p. 1332) are light and of open texture. The colour isvery white, and the raw material, which has only beenbrought into use very lately, appears to be of remarkablyline quality. As there happens to be a considerabledemand in Spain for various articles of fine pottery, themore extensive working out of this deposit appears to bea very important matter.
From the Zollvcrein we find one exhibitor of fire-clay
and brick crucibles. Mr. Von Mueman, of Siegburg onthe Rhine (West Prussia , 319, p. 1068', who also sendschemical utensils. This manufacturer makes fire-bricksfor blast furnaces and puddling furnaces at a very mode-rate cost.
Resides the objects in refractory clay already considered,there are some others, chiefly chemical utensils, which,from their condition, magnitude, and other circumstances,are referred to Class XXVII.. and which, therefore, itbecomes our duty here to report upon. For this purposetlie Jury called in the aid of an Associate Juror, T. II.Henry, Esq., F.K.S., and have perfect confidence in theresults they have been enabled to arrive at.
The largest and most important exhibitor of cruciblesmanufactured of an admixture of fire-clay and plumbago,and required for purposes where an intense heat is em-ployed, as for the melting of steel and reducing theprecious metals, is Mr. II. W. Reel, of London (Class I.,435, p. 161), to whom a Prize Medal lias been granted.The crucibles in question are described, both in this andother countries, as if made of plumbago, but consist, infact, of an admixture of that mineral, in variable propor-tions, with the finest and purest fire-clay. The introduc-tion of the plumbago, is, however, a very important; modification, and acts by preventing the injurious effects; of contraction and expansion during change of tempera-ture. Resides plumbago, other forms of carbon aresometimes used, especially pounded coke. The best. crucibles for the purposes that require the greatest resist-ance, are either made of one-half of a finely-ground cementor paste, consisting of old crucibles and fire-clay and one-half coke and graphite, or of larger proportions of clay ;but those used for the assay of the precious metals aresometimes made of two-thirds graphite.
The crucibles of Mr. Fuel are of the very best quality,and the Associate Juror, Mr. Henry, thus reports onthem:—“Mr. Ruel has so improved the black-lead orplumbago crucibles, as to drive the foreigners out of theEnglish market, and his articles are preferred abroad. Ihave repeatedly tried them and have found them excellent.Messrs. Brown and Wingrove, the gold smelters, use them■ exclusively, I understand, and in order to make sure Ihave asked them for a written opinion.* Fuel's assaycrucibles resist the action of fused oxide of lead muchbetter than any others I have tried. Mr. Ruel is, Ibelieve, the oldest crucible maker in this way, and Ithink his great merit lies in working steadily for aconsiderable time to improve the English manufacture,and gradually vanquish the strong prejudice in favourof a foreign article by the superiority of his own pro-duction.”
To Messrs. Lorenz, Kapeeekr, and Son, of Hafnerszell,near Passau (Ravaria, 28, p. 1099), a Prize Medal has alsobeen awarded for black-lead crucibles, which are describedas of more refractory character than usual, and whichappear to justify this account. The specimens sentinclude one of very unusual dimensions, measuring 2 feethigh and 20 inches in diameter. They are very wellmade. These manufacturers have long enjoyed a veryhigh reputation in the European market, and theircrucibles are extensively sold, having been generallyregarded as the nearest rivals to those made of Stour-bridge clay.
Mr. F.Coste, ofTilleur, Libge (Belgium, 397, p. 1163),is an exhibitor of plumbago crucibles of good quality,and is considered worthy of Honourable Mention. Thosehe exhibits are of two kinds, one of them not containingplumbago, but the former, adapted for melting steel, areso contrived as not to require removal for a fresh charge,and thus present a novelty of construction.
Other plumbago crucibles are sent by Mr. G. R.Atwood, of Massachusetts (United States , 426, p. 1463),but they are understood to be really English , made from
* The written opinion thus requested has been submittedto the Jury, and establishes the fact that this exhibitor’scrucibles are of the very best quality for all the most im-portant purposes for which sucli utensils are required.