urface as is not covered by soot.

Water-tube boilers in general are from the nature of their design more
readily accessible for cleaning than are fire-tube boilers.

Inspection--The objections given above in the consideration of the
inability to properly clean fire-tube boilers hold as well for the
inspection of such boilers.

Repairs--The lack of accessibility in fire-tube boilers further leads to
difficulties where repairs are required.

In fire-tube boilers tube renewals are a serious undertaking. The
accumulation of hard deposit on the exterior of the surfaces so enlarges
the tubes that it is oftentimes difficult, if not impossible, to draw
them through the tube sheets and it is usually necessary to cut out such
tubes as will allow access to the one which has failed and remove them
through the manhole.

When a tube sheet blisters, the defective part must be cut out by
hand-tapped holes drilled by ratchets and as it is frequently impossible
to get space in which to drive rivets, a "soft patch" is necessary. This
is but a makeshift at best and usually results in either a reduction of
the safe working pressure or in the necessity for a new plate. If the
latter course is followed, the old plate must be cut out, a new one
scribed to place to locate rivet holes and in order to obtain room for
driving rivets, the boiler will have to be re-tubed.

The setting must, of course, be at least partially torn out and
replaced.

In case of repairs, of such nature in fire-tube boilers, the working
pressure of such repaired boilers will frequently be lowered by the
insurance companies when the boiler is again placed in service.

In the case of a rupture in a water-tube boiler, the loss will
ordinarily be limited to one or two tubes which can be readily replaced.
The fire-tube boiler will be so completely demolished that the question
of repairs will be shifted from the boiler to the surrounding property,
the damage to which will usually exceed many times the cost of a boiler
of a type which would have eliminated the possibility of a disastrous
explosion. In considering the proper repair cost of the two types of
boilers, the fact should not be overlooked that it is poor economy to
invest large sums in equipment that, through a possible accident to the
boiler may be wholly destroyed or so damaged that the cost of repairs,
together with the loss of time while such repairs are being made, would
purchase boilers of absolute safet