hich again are fastened two longitudinals of wood 12 in.
square in section, and which in their turn carry the rails of the permanent
way.

The gauge of the Dom Pedro Segundo Railway is 1.60 meters, or 5 ft. 3 in.
nearly, between the rails. At each end of the transverse Barlow rails is
fixed the customary simple iron handrail, carried by light cast-iron
standards. The iron piers are each formed of four columns, and the columns
consist of two Barlow rails, with a slotted iron plate 1/2 inch thick let in
between the rails, and the whole being riveted together connects each pair
of side columns.

The details show the system of cross and diagonal bracing. The columns are
each supported by four buttresses formed of plates and angle-irons. These
buttresses, fastened with bolts 8 ft. 3 in. long, let into the masonry
pillars, secure the stability of the viaduct against lateral strains, due
mostly to the centrifugal force caused by the passage of the trains.

The Barlow rails, which constitute the peculiarity of the structure, are
from those taken up from the permanent way when the Vignoles pattern of
rail was adopted on this railway. The whole of the foundations were built
without difficulty. The principal parts of the iron work were calculated to
resist the strains resulting from a weight of 4 tons 8 cwt. per lineal
meter traveling over the viaduct at a velocity of 60 kilometers, or about
37 miles, per hour.

In spite of its fragile appearance this viaduct has, up to the present
time, served in a most satisfactory manner the purpose for which it was
built.--_Engineering_.

* * * * *

SEA-GOING TORPEDO BOATS.

All investigations of the sea-going qualities of torpedo boats show that
while the basin experiments are highly satisfactory, those made at sea
prove with equal force the unreliability of these craft when they leave the
coast. At the beginning of the Milford Haven operations, the boisterous
weather necessitated the postponing of operations, on account of the
unfitness of the torpedo boat crews to continue work after the twelve hours
of serious fatigue they had already undergone. In the French evolutions,
the difficulties of the passage from Bastia to Ajaccio, although not
remarkably severe, so unfitted fifteen of the twenty boats that they could
take no part in the final attack. In two nights we find recorded collisions
which disable boats Nos. 52, 61, 63, and 72, and required