220 Review of the Practical Tourist. 
hard as marble; for the purpose of detaching fragments by explo- 
sions of gunpowder. ‘They commence working next the roof, and 
carry rd the excavations in the form of broad steps, breaking 
up successively the several tiers or layers, The stunning reverbera- 
tions of the explosions, following one after another in quick succes 
sion, cause the startled visitant to shrink back with a momentary 
feeling of alarm, whilst the very roof seems to be upheaved, and the — 
pillars to tremble under their load. 
“In order to show us the extent of the mine, our conductor fred 
a preparation of gunpowder, termed blue-lights, which he had provi- 
ded for the purpose of affording a brilliant illumination. On firing 
the combustible preparation, instantly, countless remote square pil- 
lars seemed to start up from a large plain, distinctly visible, as if 
the r meridian sun had burst in upon the gloomy cavern. 
After the flashes have thus suddenly illuminated with a dazzling, 
fearful light, the vast aisles, and pillars of salt, they as suddenly ex- 
pire, and all the scene, as if conjured up into momentary existence 
by some magic spell, again becomes shrouded in darkness.” 
Among the most important manufacturing operations carried on 
in Manchester, are those connected with the priating of cotton cloths 
or calico. The mere designing or inventing of new patterns of 
figures for the printers is of itself a considerable business, furnishing 
regular employment to many persons, who gain a good living by their 
ingenuity in this branch of business. The process of engraving the 
cape cylinders and blocks for printing, is another considerable 
siness. Inone apartment, I saw nearly thirty men at work. The 
wal Siar and sprigs are engraved, or rather sunk into the surface 
of the copper cylinders by steel dies, instead of being eut by the — 
graver. The pattern of a flower, or other figure, is thus pany 
impressed in the twinkling of an eye. 
“* After the process of engraving is completed, the copper cylinder 
is —, ina strong Seana where it is made to revolve ee steam pinot 
