a close association.

England already possesses a famous subaqueous tunnel in that known as
the Severn tunnel under the river of that name. It is four and a half
miles long, although it was built largely through rock. Water gave
much trouble in its construction which occupied thirteen years from
1873 to 1886. Pumps were employed to raise the water through a side
heading connecting with a shaft twenty-nine feet in diameter. The
greatest amount of water raised concurrently was twenty-seven million
gallons in twenty-four hours but the pumps had a capacity of sixty-six
million gallons for the same time.

The greatest tunnel in Europe is the Simplon which connects Switzerland
with Italy under the Simplon Pass in the Alps. It has two bores twelve
and one-fourth miles each and at places it is one and one-half miles
below the surface. The St. Gothard also connecting Switzerland and
Italy under the lofty peak of the Col de St. Gothard is nine and
one-fourth miles in length. The third great Alpine tunnel, the Arlberg,
which is six and one-half miles long, forms a part of the Austrian
railway between Innsbruck and Bluedenz in the Tyrol and connects
westward with the Swiss railroads and southward with those of Italy.

Two great tunnels at the present time are being constructed in the
United States, one of these which is piercing the backbone of the
Rockies is on the Atlantic and Pacific railway. It begins near
Georgetown, will pass under Gray's peak and come out near Decatur,
Colorado, in all a length of twelve miles. The other American
undertaking is a tunnel under the famous Pike's Peak in Colorado which
when completed will be twenty miles long.