The Locomotive - Lighthouse Survival Blog

162 THE LOCOMOTIVE. [November,
since that time, showing some of the strange and interesting things that are discovered
by our inspectors. It would have been easy for us to accumulate a mass of such
material sufficient to fill a good-sized building; but we have always had in mind the
illustrative value of our specimens, rather than their number, and we consider that our
present collection is of correspondingly greater interest and importance.
The room in which these treasures are stored might very properly be called a
museum; but since many of the specimens in the collection illustrate errors of con-
struction, and dangerous defects that developed during the ordinary operation of the
boilers from which they were taken, we have formed the habit of referring to the room
in question as our "chamber of horrors'"; and that is the reason we adopted the fore-
going title for the present article. The melancholy aptness of this title is also em-
phasized by the fact that not a few of the specimens in the collection are from boilers
that have exploded and caused great loss of life and property. The two large pieces of
plate that are seen in the engraving leaning against the right-hand side of the double
glass door, for example, possess a peculiarly sad interest to us, because the boiler from
which they were taken exploded and killed one of our inspectors who was present in
the plant at the time, to make an external inspection of this very boiler.
The collection comprises almost every kind of defect that can be represented by
means of specimens that are small enough to be stored conveniently in a museum of this
sort. We have, for example, a striking collection of feed pipes and blow-off pipes,
showing the ways in which these deteriorate in service. "We have blow pipes that are
filled with deposit until they were badly burned by the hot furnace gases, and we have
feed pipes that have also been filled by deposit until it would be impossible to force any
considerable quantity of water through them, under any pressure whatever. We have
many specimens of brass blow-off pipes, too, that are burned and burst. There are
also in the collection numerous sections from shell plates, showing beautiful bulges
and blisters; some fine specimens of plates that have been corroded, in use, to an
almost incredible degree; many tubes that have been pitted or corroded or otherwise
damaged, until unfit for use; some excellent examples of burst water tubes from sectional
boilers, and of similar tubes filled with scale matter so as to be useless and
dangerous; and fittings that have been broken by water-hammer action in undrained
steam pipes. It would be impossible to enumerate all the different kinds of defects
that are illustrated by the collection, but it may be said that there is hardly any kind of
trouble that can arise in connection with boilers that is not represented, in some
manner, by one or more of the specimens that may be seen in this "chamber of
horrors."
The fragments of plates and tubes and other constructive elements that have been
referred to above do not by any means exhaust our exhibit, for we have also a fine collection
of samples of deposit and sediment of all kinds. These include scale in which
the predominant substances are sulphate of lime, carbonate of lime, magnesia, salt, and
other minerals that are introduced into the boiler in the dissolved state, and also huge
aggregates or conglomerates that were formed by the consolidation of loose flakes of
one sort and another, and are now cemented together into one solid mass. Some of
these conglomerate scales are so amazingly solid and massive that it is hard to believe
that a boiler could run for five minutes with such deposits w T ithin it. Those who have
not given special attention to this subject would be surprised at the great variety of
forms exhibited by specimens of boiler scale, even when the chemical composition of
the samples compared is substantially the same. Some of the specimens in our museum
are solid and stony, and hard enough to take a good polish, while others, of nearly the