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The chief marble manufacture of England is in a partof Derbyshire , remarkable for its picturesque beauty,extending along the valley of the Derwent and its prin-cipal tributary the Wye, from below Buxton to Derby.The machinery for sawing and polishing was first esta-blished in Derbyshire , at the village of Ashford, nearBakewell , in the year 1748, water being the motive power.About the year 1810, similar machinery was erected atBakewell . Both these works are situated nearthe quarries.Within a few years other works have been established atBuckland Hollow, near the line of the Midland Railway.These works give employment to upwards of seventypersons : about one-fifth work in the quarries : the rest aremarble masons, polishers, &c., employed in part uponforeign marbles. Besides these three works, others havebeen established in Derby for many years.
The most important marbles of Derbyshire are the black,the rosewood, the encrinital, the russet, or bird-eye, and amottled dark and light-gray kind, occasionally containingnumerous small corals. Of some of these there are severalvarieties. Others might be added to the list of thosefound in the northern part of the country, one of which isa beautiful red, resembling the j'osso antico, but it isobtained only in small blocks or lumps.
At Wetton, in Staffordshire, near the borders of Derby-shire , are marbles differing much from the above, butthey have not been brought into any considerable use, andare generally subject to flaws.
The black marble is of very fine colour and texture, butlarge slabs free from small veins of calcareous spar arerare. The best quality occurs in beds of from 3 to S inchesin thickness; some beds are thicker. This marble is,perhaps, superior to the similar kinds found in other partsof Europe , and is greatly valued for inlaying. It is tough,and contains a good deal of carbon, which imparts thecolour. Within a very recent period the finer slabs havebeen inquired for, for exportation to Florence, Malta , andSt. Petersburg, besides being used in Devonshire andDerbyshire .
Black marble is extensively used for ornamental objects,such as vases, pedestals, chimney-pieces, See., for which itis admirably adapted. It is occasionally ornamented invarious ways, as by etching, engraving, and inlaying. Inthe two former processes the polished surface is removed,and the brown colour of the rough marble exposed.Powdered white-lead is sometimes rubbed into the etchedsurface to increase the effect. By a peculiar process usedat Derby, the brown colour is sometimes exposed withoutthe polish of the marble being destroyed. The ornamentproduced by this process is more durable than the ordinaryetching.
The rosewood marble is extremely hard, and of closetexture. The beds are of considerable thickness ; but themost beautiful part of the marble is only about 6 inchesthick. The name is derived from the marking of themarble being somewhat similar to that of rosewood.
The encrinital marble is the one in most extensive use,and contains very' numerous fossils, consisting almostexclusively of the broken fragments of encrinital stemsoften entangled in coral. It may be obtained in blocks oflarge superficies, and of a thickness of 2 to 2^ feet.
The russet, or bird-ejc, takes its name from its colourand appearance, the shades varying from light gray tobrown. It contains numerous minute fossils, also encri-nital, and is found in beds of from G to 18 inches inthickness.
The dark and light mottled gray marble (called New-burgh marble), and the overlying bed, which is coralline,can be obtained from 1 to 2 feet thick.
The manufacture of Devonshire marble is much moremodern, and the material is generally less manageable.Almost all the beautiful marbles of this county, especiallythose near Plymouth, are fossiliferous, brittle, and veryapt to contain veins and cracks. They are illustrated bysome beautiful and interesting specimens, which will be
The columns formed of pieces of black marble andalabaster (exhibited in Class I., Ko. 146,by J. andG. Hall)show the various processes, beginning with the rough stone Iat the bottom, and ending with the final polish at the top.
alluded to as the works of individual exhibitors. Themarbles of Devonshire belong to an older geological periodthan those of Derbyshire , the latter being exclusively ofthe carboniferous limestone series, underlying the coalmeasures and the millstone grit, while the former are ofthe Devonian , or middle Pakcozoic epoch.
The other kinds of marble, obtained from variouslocalities, do not appear to involve any peculiar methodof manufacture, nor is it necessary to give further detailson this subject. It may well be supposed that the cuttingand polishing of alabaster, a material much softer thanmarble, is in a corresponding degree easier. It is saidthat soap is used in polishing alabaster, and some of theobjects constructed of this material are rendered trans-lucent by being soaked in some kind of oil. The chieflocality of this manufacture has long been in the north ofItaly, near Leghorn , where the material is very abundant.A considerable number of alabaster ornaments are nowmade in Derbyshire , chiefly from Italian models: thoseoriginated on the spot are not yet remarkable for excel-lence of desigu. The material is obtained in that countyin considerable quantities.
In proceeding to mention the different exhibitors inthese materials, we may begin with an account of theseries of manufactured marbles sent from various places.
a. General Collections of Marbles.
There are several collections of marbles exhibited fromforeign countries, in which the specimens are at leastpartly manufactured, and some even finished, althoughthe general intention in such cases seems to have been toexhibit them rather as raw materials than as specimens ofmanufacture. Many of them thus belong to Class I.(Raw Materials of the Mineral Kingdom); but otherspartake so distinctly of the character of the objects inClass XXV1L, and so clearly involve processes of manu-facture, that the Jury of this latter Class have thought itnecessary to allude, however briefly, to them. To someof these they have voted Medals.
The collection of Italian marbles forwarded by theRoyal Tkchxological Institute of Tuscany (Tuscany ,Nos. 1 and 98, p. 1290) is of very considerable interest,and includes many varieties little known in this country,some of them remarkable for their beauty and excellence.The Jury mark their sense of the value of this series byawarding a Prize Medal to the Institution by which ithas been sent.
To M. Dejeaxt (Portugal , 232 to 247, 250, 251, 259 to274, p. 1310) a Prize Medal has been awarded, for a mostinteresting series of Portuguese marbles, of great variety,and including many of considerable beauty. A fine col-lection of Pyrenaean marbles is sent by Messrs. Deryilleand Co. (France , 1G2, p. 1181), to whom also a PrizeMedal is awarded (Prize Medal given by Class I. also);and an almost equally interesting series of specimensfrom Languedoc is contributed by M. Cafeort (France,444, p. 1199), of whom Honourable Mention is made.M. Colin (France , 1564, p. 1251), who has exhibited aseries of polished marbles, granites, and serpentines fromthe Vosges mountains, is also Honourably Mentioned.
The Greek Government (Greece , 26-49, pp. 1404-05)lias sent samples from some of those quarries whosereputation dates as far hack as history can record, butthey are not in a condition of manufacture to justifyextended notice here. 'Die marbles are decidedly inferiorin quality to some of those obtained more recently ingreater abundance from nearer localities, but if the quarrieswere properly and extensively worked, far better materialmight probably be obtained.
The Egyptian Government (Egypt , 1-4, p. 1408) hasbeen induced to open, of late years, the rich stores oforiental alabaster, a material celebrated in antiquity, andof which is made one of the most interesting works inmineral manufactures in the Great Exhibition. * Thecondition of this marble is very peculiar, but it wouldseem that considerable quantities of excellent quality mightreadily be obtained. It is a peculiar condition of lirne-
* The object alluded to is the Tazza, by Mr. Dallamoda(Rome, 19).
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