beyond admissible limits, thereby causing the resistance of the gun to
be less than that prescribed.[4]

[Footnote 4: When the inner tube is strengthened by means of
wire, the initial or natural stresses in the latter may be
neglected on account of its thinness; but when the thickness of
the hoops is reduced, and the number of layers thereby increased,
then the value of the initial stresses in these hoops is a very
important factor with respect to the decrease or increase Of the
powers of resistance of the gun.]

It is evident, from what has been said, that in order to determine
precisely the resistance of hollow cylinders to internal pressures, and
to make the correct calculations for hooping tubes, it is absolutely
necessary to know whether internal initial stresses exist in the tube
and in the hoops, and to ascertain what their nature and intensity may
be--that is to say, whether they are useful or detrimental; yet it is
incontestable that in the construction of modern ordnance no attention
has been paid to the investigations indicated. If it be possible to
ignore these considerations in the manufacture of guns of small caliber,
and where the thickness of metal is not sufficiently great to admit of
strongly developed internal stresses, such is by no means the case with
the colossal and costly weapons of the present day. In these the
thickness of metal in the tube and hoops is very great; hence the
extreme probability of very considerable internal stresses developing
themselves. That the strength of large guns is often far below that
anticipated is demonstrated, year by year, by the repeated cases of
failure. Consciousness as to the want of strength in such guns is made
evident by the precautionary measures as to their use everywhere
adopted. The heavy artillery produced in the gun factories of Europe is