‘Two obelisks of salt commemorated the visit of Francis I. and his Empress in another spacious, irregular vault, through which we passed by means of a wooden bridge, resting on piers of the crystalline rock. After we had descended to the bottom of this chamber, a boy ran along the bridge above with a burning Bengal-light, throwing flashes of blue lustre on the obelisks, on the scarred walls, vast arches, the entrances to deeper halls, and the far roof, fretted with the picks of the workmen. The effect was truly magical. Presently we entered another and loftier chamber, yawning downwards like the mouth of hell, with cavernous tunnels opening out of the further end. In these tunnels the workmen, half naked, with torches in their hands, wild cries, fireworks, and the firing of guns (which here so reverberates in the imprisoned air that one can feel every wave of sound), give a rough representation of the infernal regions, for the benefit of the crowned heads who visit the mines. A little further, we struck upon a lake four fathoms deep, upon which we embarked in a heavy, square boat, and entered a gloomy tunnel, over the entrance of which was inscribed (in salt letters) “Good luck to you!” Midway in the tunnel, the halls at either ends were suddenly illuminated, and a crash, as of a hundred cannon bellowing through the hollow vaults, shook the air and water in such wise that our boat had not ceased trembling when we landed in the further hall. A tablet inscribed “Heartily welcome!” saluted us on landing. Finally, at the depth of 450 feet, our journey ceased, although we were but half way to the bottom. The remainder is a wilderness of shafts, galleries, and smaller chambers, the extent of which we could only conjecture. We then returned through scores of tortuous passages to some vaults, where a lot of gnomes, naked to the hips, were busy with pick, mallet, and wedge, blocking out and separating the solid pavement. The process is quite primitive, scarcely differing from that of the ancient Egyptians in quarrying granite. The blocks are first marked out on the surface by a series of grooves; one side is then deepened to the required thickness, and wedges being inserted under the block, it is soon split off.
‘The number of workmen employed in the mines is 1,500, all of whom belong to the ‘upper crust,’—that is, they live on the outside of the world. They are divided into gangs, and relieve each other every six hours. Each gang quarries out, on an average, a little more than 1,000 cwt. of salt in that space of time, making the annual yield 1,500,000 cwt.!
‘The men we saw were fine, muscular, healthy-looking fellows; and the officer, in answer to my questions, stated that their sanitary condition was quite equal to that of field labourers. He explicitly denied the ridiculous story of men having been born in these mines, and having gone through life without ever mounting to the upper world.’
As far as explored, the salt-bed occupies a space of 9,000 feet in length and 4,000 in width, and consists of five successive stages or stockwerke, separated from each other by intervening strata of from 100 to 150 feet in thickness, and reaching to a depth of 1,500 feet. Notwithstanding the immense amount of salt already quarried from this wonderful deposit, which, according to authentic records, has been worked ever since the twelfth century, and perhaps even much earlier, it is estimated that, at the present rate of exploitation, the known supply cannot be exhausted under 300 years.
It is a remarkable circumstance that sources of sweet water are found in the mines in close proximity to the salt, a circumstance which is owing to the latter not forming a continuous stratum, but being imbedded in large nests or insular masses in the tertiary clay of the mountain, so that in several places the water filtering from the top is able to gush forth in the subterranean galleries without any saline admixture.
In the summer of 1868 a serious accident happened to the mines of Wieliczka, which at one time was supposed to threaten their total destruction. In the hope of discovering valuable potash salts, such as occur at Stassfurt, in the vicinity of the rock-salt, a boring was imprudently attempted at a great depth, through a contiguous aquiferous stratum, and the consequence was that, instead of meeting with the expected result, a powerful spring was tapped, which, pouring forth an immense volume of water, filled the lower galleries. The inhabitants of the village of Wieliczka, which is situated above the mines, were terrified. They not only feared for the ruin of the mine, which afforded them their chief means of subsistence, but dreaded also the falling in of their houses, in consequence of the melting of the salt-pillars which upheld the flooded galleries.
Fortunately their fears proved to be exaggerated, as the inundation, which remained confined to the lower galleries, is now being rapidly brought under by means of powerful steam pumps, and measures have been taken for blocking up the spring. Even supposing the water to have continued pouring in with undiminished force, and without any effort being made to drain it off, the excavations are so vast that it would have taken many years to fill them.
Besides the mines of Wieliczka, Austria possesses many other considerable deposits of rock-salt in Gallicia (Bochnia), Hungary, and Transylvania. In Salzburg (Ischl, Halstadt Hall), Tyrol, and the neighbouring mines of Berchtesgaden, in Bavaria, the salt does not occur in large solid masses, fit to be at once extracted from the bosom of the earth, but imbues masses of gypsum and anhydrite, which become quite light and porous when the salt has been removed by water. As it would be too expensive to remove this compound, an ingenious method has been contrived for introducing water into the mines from above, and drawing it off again through an adit or lower gallery as soon as it is saturated with salt.
The brine thus obtained at Berchtesgaden is then conveyed, by means of pipes or conduits, to Reichenhall and Rosenhain, where the necessary fuel for its evaporation is near at hand. The distance from Berchtesgaden to Rosenhain is no less than thirty leagues; and between both places many high mountains, steep rocks, and narrow gorges intervene. The works which lead the brine over this distance, and through all these natural obstacles, may therefore justly be considered as a masterpiece of mechanical skill. As the pipes must often ascend mountains, the highest elevation above the pit being 1,218 feet, and then again slant down into ravines; as in many parts rocks had to be levelled and forests cut down for the purpose of laying them, and as they are subject to frequent damage in a severe climate, it may easily be imagined that the greatest engineering power was required for the execution of so grand a work.
Hydraulic machines serve to raise the brine over the mountains, and the water-power of the rivulets descending from the heights is used for forcing it upwards. The contrivance is so admirable that the small machine at Berchtesgaden raises 270 cwt. of brine to a height of 311 feet by means of an equal weight of water descending from a height of 375 feet. In some parts the tubes of this colossal duct run along the high road, in others tunnels have been pierced to shorten the distance.