Nitro-Explosives: A Practical Treatise | Page 5

the various buildings, and should slope gently from one to the
other. It is also desirable that, as far as possible, they should be
protected by earth-work banks, in the same way as the danger buildings
themselves. They should also be provided with covers, which should be
whitewashed in hot weather.
A great deal of attention should be given to these conduits, and they
should be very frequently inspected. Whenever it is found that a portion
of the lead lining requires repairing, before cutting away the lead it
should be very carefully washed, for several feet on either side of the
portion that it is intended to remove, with a solution of caustic soda or
potash dissolved in methylated spirit and water, and afterwards with
water alone. This decomposes the nitro-glycerine forming glycerine
and potassium nitrate. It will be found that the mixed acids attack the
lead rather quickly, forming sulphate and nitrate of lead, but chiefly the
former. It is on this account that it has been proposed to use pipes made
of guttapercha, but the great drawback to their use is that in the case of
anything occurring inside the pipes, such as the freezing of the nitro-

glycerine in winter, it is more difficult to find it out, and the condition
of the inside cannot be seen, whereas in the case of wooden conduits it
is an easy matter to lift the lids along the whole length of the conduit.
The buildings which require to be connected by conduits are of course
those concerned with the manufacture of nitro-glycerine. These
buildings are--(1) The nitrating house; (2) the separating house; (3) the
filter house; (4) the secondary separator; (5) the deposit of washings; (6)
the settling or precipitation house; and each of these buildings must be
on a level lower than the preceding one, in order that the nitro-glycerine
or acids may flow easily from one building to the next. These buildings
are, as far as possible, best placed together, and away from the other
danger buildings, such as the cartridge huts and dynamite mixing
houses, but this is not essential.
All danger buildings should be protected by a lightning conductor, or
covered with barbed wire, as suggested by Professor Sir Oliver J.
Lodge, F.R.S., Professors Zenger, of Prague, and Melsens, of Brussels,
and everything possible should be done to keep them as cool as
possible in the summer. With this object they should be made double,
and the intervening space filled with cinders. The roof also should be
kept whitewashed, and the windows painted over thinly with white
paint. A thermometer should be suspended in every house. It is very
essential that the floors of all these buildings should be washed every
day before the work-people leave. In case any nitro-glycerine is spilt
upon the floors, after sponging it up as far as possible, the floor should
be washed with an alcoholic solution of soda or potash to decompose
the nitro-glycerine, which it does according to the equation[A]--
C_{3}H_{5}(NO_{3})_{3} + 3KOH = C_{3}H_{8}O_{3} +
3KNO_{3}.
[Footnote A: See also Berthelot, Comptes Rendus, 1900, 131[12], 519-
521.]
Every one employed in the buildings should wear list or sewn leather
shoes, which of course must be worn in the buildings only. The various
houses should be connected by paths laid with cinders, or boarded with

planks, and any loose sand about the site of the works should be
covered over with turf or cinders, to prevent its blowing about and
getting into the buildings. It is also of importance that stand pipes
should be placed about the works with a good pressure of water, the
necessary hose being kept in certain known places where they can be at
once got at in the case of fire, such as the danger area laboratory, the
foreman's office, &c. It is also desirable that the above precautions
against fire should be tested once a week. With regard to the heating of
the various buildings in the winter, steam pipes only should be used,
and should be brought from a boiler-house outside the danger area, and
should be covered with kieselguhr or fossil meal and tarred canvas.
These pipes may be supported upon poles. A stove of some kind should
be placed in the corner of each building, but it must be entirely covered
in with woodwork, and as small a length of steam pipes should be
within the building as possible.
In the case of a factory where nitro-glycerine and dynamite are
manufactured, it is necessary that the work-people should wear
different clothes upon the danger area than usual, as they are apt to
become impregnated with nitro-glycerine, and thus not very desirable
or safe to wear outside the works. It is also necessary that these clothes
should not contain any pockets, as this