132 CRITICAL NOTICES OF NEW PUBLICATIONS. 



the position in which it is found — sometimes injected between the 

 other strata,, forming dykes of hard rock ; and sometimes appearing 

 above the surface in considerable elevations — to be of volcanic ori- 

 gin ; and in fig. 3 it has been endeavoured to give some idea of the 

 conceivable action of the convulsion of Nature, which was accompa- 

 nied by the eruption of such a mass of fused matter. 



Thus, then, figs. 1 and 3, though, of course, imaginary in their 

 details, may be considered as presenting, in section, the probable 

 disposition of the various strata, from the north-eastern point, where 

 the thick coal crops out and is lost near Bilston, to the south-west- 

 ern boundary, where it rapidly descends, as it were in steps, to great 

 depths, exhibiting a minature picture of the spectacle which would 

 meet the eye were a deep cutting to be made through the entire 

 district, and shewing such faults, dykes, elevations, and depressions 

 as the experience of the miner discovers actually to prevail. The 

 position of the thick coal and the lime- stone, respectively, being 

 marked by the shaded lines m and n. 



The remaining figures on our plate, (figs. 3, 6, and 8), refer to 

 the chapter on the Coal Mine, which contains a good deal of graphic 

 and lively description, (p. 36, et seq.J. The work of raising the 

 coal is usually performed by the steam-engine, but in certain situa- 

 tions where the dei)th is not great, and where the dip is considerable, 

 the more ancient machine, the Gin, (fig. 8) is still used. The name 

 of this apparatus, as our author speculates at page 7^ is '' a slipshod 

 corruption or abbreviation of '^ engine' — as we say van, adopting the 

 final syllable of caravan." An examination of the figure will suffi- 

 ciently explain its construction and adaptation. 



Figs. 5 and 6 are, respectively, a section and a ground-plan of the 

 mode of " getting" the ten-yard coal ; to which the following refer- 

 ences may be made : — c the shaft / g g the entrances to the stalls, 

 or places where the work is proceeding; b b pillars of coal of great 

 thickness, left to support the superincumbent strata ; a the ungot 

 coal. The white lines round the working, (g g, fig. 6,) represent 

 the air-head — a narrow passage with apertures communicating with 

 the openings or stalls, and constructed for the purpose of introduc- 

 ing a current of pure air into the mine. A supposed improvement 

 in this important department of mining — Ventilation — is also exhi- 

 bited in these figures : — d d is an air-pipe conducted down the shaft 

 c, and extending by its ramifications, e e, into the working stalls ; 

 capable of being easily lengthened, shortened, or removed, as the 

 case requires, p is a blowing, or air-cylinder, attached to the mine- 

 engine, by the operation of which a constant and powerful stream 

 of air would be impelled into the mine, spreading itself in jets from 

 the mouths of the arms, b e, and driving out the deleterious 

 vapours and gases that are generated in the recesses of the mine. 

 This mode of ventilation, it appears, is suggested by Mr. Harper of 

 Wednesbury. It has never been brought into practice, but it aji- 

 pears to be dictated by good sense, and. if found effectual, would 

 have the additional merit of economizing labour, and of preventing 



