Potosi, Hale & Norcross, and Savage mining companies; hence its name
of the Combination shaft. This shaft has now reached a perpendicular
depth of a little over 3,100 feet. There is only one deeper vertical
shaft in the world--the Adalbent shaft of the silver-lead mines of
Przibram, Bohemia, which at last accounts had reached a depth of 3,280
feet. The attainment of that depth was made the occasion of a
festival, which continued three days, and was still further honored by
the striking off of commemorative medals of the value of a florin
each. There is no record of the beginning of work on this mine at
Przibram, although its written history goes back to 1527.

Twenty years ago very few mining shafts in the world had reached a
depth of 2,000 feet. The very deepest at that time was in a
metalliferous mine in Hanover, which had been carried down 2,900 feet;
but this was probably not a single perpendicular shaft. Two vertical
shafts near Gilly, in Belgium, are sunk to the depth of 2,847 feet. At
this point they are connected by a drift, from which an exploring
shaft or winze is sunk to a further depth of 666 feet, and from that
again was put down a bore hole 49 feet in depth, making the total
depth reached 3,562 feet. As the bore hole did not reach the seam of
coal sought for, they returned and resumed operations at the 2,847
level. In Europe it is thought worthy of particular note that there
are vertical shafts of the following depths:

Feet.
Eimkert's shaft of the Luganer Coal Mining
Company, Saxony 2,653

Sampson shaft of the Oberhartz silver mine,
near St. Andreasberg, Hanover. 2,437