service which is an absolute necessity. In this connection the general
features of the Nicaragua Canal, in its latest form, were referred to,
and the opinion expressed that even were all difficulties in the way of
the Ship Railway eliminated, it could not be superior to the canal in
respect of adaptiveness.

In point of political security he claimed that both Tehuantepec and
Nicaragua were reasonably free from doubts, with the advantage in favor
of the latter, while at Panama no security, for United States interests
at least, could be counted on, without the liability of a military
expenditure far exceeding the cost of the canal itself.

The matter of comparative cost of construction and operation was
discussed generally, and in conclusion the author stated that "this
all-important question is still an open one, of which the future needs of
our country justify and demand at this time a most searching scrutiny,
and moreover our interest and the interest of mankind require that before
this century closes, the best possible pathway between the Atlantic and
the Pacific shall be open to the navies of the world."

The paper was illustrated with maps and diagrams.

* * * * *

THE MERSEY TUNNEL.

The Mersey Tunnel was lately opened by the Prince of Wales, and, as the
London _Standard_ says, after an infancy of troubles and failures, and a
ten years' middle age of inaction, the Mersey Tunnel emerges into
notoriety under the hands of Mr. James Brunlees and Mr. C.D. Fox, and of
Mr. Waddell, the contractor, as a triumph of engineering skill. The
tunnel is 1,250 yards in length. It is driven through solid, but porous,
red sandstone, through which the water has percolated in volumes during
construction, at a level of about 30 feet below the bed of the river. It
is lined throughout with blue bricks, the brickwork of the invert being 3
feet in thickness. Its transverse section is a depressed oval 26 feet in
width and 21 feet in height, and it contains two lines of railway. At a
depth of about 18 feet below the main tunnel there is a continuous
drainage culvert 7 feet in diameter, entered at intervals by staple
shafts. There are two capacious underground terminal stations 400 feet
long, 50 feet broad, and 38 feet high, and gigantic lifts for raising 240
passengers in forty seconds, from more than three times the depth of the
Metropolitan Railway to the busy streets above. These splendid lift