In the examinations held by duly appointed officers to determine the
fitness of candidates for receiving an engineer’s license the principal
stress is laid upon the applicant’s knowledge of the parts and true
proportions of the various designs of steam boilers, and his experience
in managing them.
In fact, if there were no boilers there would be no examinations, as
the laws are framed, certificates issued and steam boiler inspection
companies formed to assure the public safety in life, limb and
property, from the dangers arising from so-called mysterious boiler
explosions.
Hence an almost undue proportion of engineers’ examinations are devoted
to the steam boiler, its management and construction. But the subject
is worthy of the best and most thoughtful attention. Every year adds to
the number of steam boilers in use. With the expanding area and growth
of population, the number of steam plants are multiplied and in turn
each new steam boiler demands a careful attendant.
There is this difference between the boiler and the engine. When the
latter is delivered from the shop and set up, it does its work with an
almost unvarying uniformity, while the boiler is a constant care. It is
admitted that the engine has reached a much greater state of perfection
and does its duty with very much more reliability than the boiler.
Even when vigilant precautions are observed, from the moment a steam
boiler is constructed until it is finally destroyed there are numerous
insidious agents perpetually at work which tend to weaken it. There is
nothing from which the iron can draw sustenance to replace its losses.
The atmosphere without and the air within the boiler, the water as
it enters through the feed-pipe and containing mineral and organic
substances, steam into which the water is converted, the sediment which
is precipitated by boiling the water, the fire and the sulphurous and
other acids of the fuel, are all natural enemies of the iron; they
sap its strength, not only while the boiler is at work and undergoing
constant strain, but in the morning before fire is started, and at
noon, night, Sundays, and other holidays it is preyed upon by these and
other corroding agents.
These are the reasons which impress the true engineer with a constant
solicitude regarding the daily and even momentary action of the steam
generator.