on an average, one and a half inches in length, and the
salmon two and three-quarter inches. They were transported in three
iron plate vessels, weighing altogether, inclusive of the water, 770
lb., and provided with air tubes through which, during the voyage, the
employes, by means of pumps, assured the respiration of the little
fish.

Our engraving represents the submersion at the moment at which
the cylinders (of which the temperature has just been taken and
compared with that of the Seine, in order to prevent too abrupt a
transition for the fry) are being carefully let down into the
river.--_L'Illustration_.

* * * * *

Figures show that the consumption of iron in general
construction--other than railroads--in this country has grown from a
little more than a million and a half of tons in 1879 to more than six
million tons in 1889. Much of this increase has gone into iron
buildings. By using huge iron frames and thin curtain walls for each
story supported thereon, as is done in a building going up on lower
Broadway, New York city, a good deal of space can be saved.

* * * * *

MODERN ARMOR.

By F.R. BRAINARD, U.S.N.

The building of a navy, which has been actively going on for the past
few years, has drawn public attention to naval subjects, and recent
important experiments with armor plates have attracted large
attention, hence it may not be amiss to give a description of the
manufacture and testing of armor. It would be interesting to wade
through the history of armor, studying each little step in its
development, but we shall simply take a hasty glance at the past, and
then devote our attention to modern armor and its immediate future.

Modern armor has arrived at its present state of development through a
long series of experiments. These experiments have been conducted with
great care and skill, and have been varied from time to time as the
improvements in the manufacture of materials have developed, and as
the physical laws connected with the subject have been better
understood. There has been very little war experience to draw from,
and hence about all that is now known has been acquired in peaceful
experiments.

The fundamental object to be obtained by the use of armor is to keep
out the enemy's shot, and thus protect from destruction the vulnerable
things that may be behind it. The first serious effort to do this
dates w