form of spike
I have seen is the curved safety railroad spike; this spike takes in
the tie a position which enables it to resist the thrust of the rail
against it much more effectually than the ordinary spike can possibly
do. I have seen in good condition, one of these curved spikes which
was said to have been driven eight times. The cost of the curved
safety spike is more than that of the ordinary spike, but it is better
made, holds the track better, and, I believe, is worth more than the
difference asked for it.--_J.A. Hall, on Construction and Maintenance
of Track, before American Society of Civil Engineers._

* * * * *

THE EXPERIMENTS AT THE ANNAPOLIS PROVING GROUNDS.

The desperate war that has been waging between the gun and armor
plate, ever since the period when protective plates were first applied
to naval constructions, is familiar to all. In this conflict the
advantage seems to lean toward the side of the gun, the power of
penetration of which can be increased to almost indefinite limits, at
least theoretically, while we quickly reach the extreme thicknesses of
metal that can be practically employed for the protection of ships.

So, in recent times, researches have been making upon the efficacy of
armor plating, no longer in its exaggeration of thickness, but in the
intrinsic quality of the metal of which it is composed. Metallurgists
have applied themselves to the work and have thus brought out various
products, among which the plates called "compound," of Messrs. Cammell
& Co., have obtained a great notoriety. These plates, formed of a true
plating of steel upon a bed of soft iron, have been much in vogue in
the English navy, and seemed as if they were to be adopted about
everywhere.

The Creusot works alone, of all competitors, were able to fight
against the general infatuation. Many comparative experiments had
already demonstrated the superiority of the Creusot "all steel" plates
over the Cammell plates, but Messrs. Schneider & Go. were not willing
to stop here, and finally produced the new nickel steel plate, which
is by far superior to their steel plates.

Some comparative trials of these various armor plates have recently
been made by a military commission of the United States at the
Annapolis proving grounds. Three plates, one a Cammell, the second a
steel, and the third a nickel steel (the two last from Creusot), were
here submitted to firing, under abs