Any boiler that has been standing idle for a few weeks or
months is a dangerous thing to enter, and no one should
attempt it until it has been thoroughly ventilated by taking ofi
all the man-hole and hand-hole plates and throwing water into
it. This is due to the presence of a gas which is generated
from the refuse and mud, or scale, which, to a greater or less
degree, remains in all boilers. Contact with fire is certain to
result in an explosion. Xot long since a locomotive was in a
roundhouse, where it had been waiting some Veeks for repairs.
Some of tlio tubes were split and a man was pulling them out.
I To liad only removed one or two when, putting in his lamp to
H<'« wliat remained, there was a fearful explosion which shook
\\u) Hhop. There are many other places which are unsafe to
unter when they have been long closed, such as wells, pits of
liny kind, and tanks. Precisely what the nature of the gas is
no one seems to know, but it is assuredly settled that a man
who go(?H into it with a light seldom comes out unharmed.
The gas most likely to fill idle boilers in cities is sewer gas,
that gcjts in through the blow-off pipe, which is left open and
g<fn*?rally connects with the sewer; hence, the connection with
i\ut Hijwcjr by the blow-off pipes should receive attention.
