Q. The usual catalogue of accidents from exploding water-backs, caused by freezing, has begun to appear in the papers. This suggests to me whether there is not a simple expedient by which the servants may ascertain whether the water-back connections are frozen or not. I would suggest the following for your consideration:

As close to the range as possible put a cock, A - Figure 113 - not in the line of the connection, but opening from it, so that by no accident can it shut off the connection. Let this pipe terminate, say, over a pan, and let the servant every morning try the cock before starting the fire. If water will not run from this cock it will be clear proof something is wrong, and then the process of thawing out the connections, together with a very slow fire in the range to gently heat the back, can be proceeded with until water runs from the cock A. Would it not be worth while for range-makers to provide such a cock in connection with the spuds for the water-back connections?

A. In the hands of an expert, or with very cautious persons who had been specially instructed in its use, the plan suggested might prove of service. It is reasonable to suppose that the water in the pipes leading to a water-back will freeze before the water in the back can; and that if the cock mentioned ran water when opened the pipes would be clear, and that, consequently, the back would be also unfrozen. But its practical value, we think, would be very little, for the simple reason that people who blow up water-backs have generally very little knowledge about such matters, and would not know what to do if they were informed a water-back was frozen. In fact, they would be apt to reason that the heat of the fire would thaw all out.

What is really wanted is a water-back that will not explode, or one that will explode at a comparatively low pressure. When the ordinary box-casting explodes the pressure necessary to burst it is seven to eight hundred pounds per square inch, or higher, and is capable of doing about as much damage as a bombshell, by the expansive force of the heat contained in the water necessary to exert such a pressure, the water flying into steam upon being liberated.

To lessen the extent and force of explosions in water-backs, pipe-coils might be used instead of box-castings, if it were not for the fact of their filling with lime-deposit, etc. With the pipe a bend may split or the pipe burst, but the whole thing will not go to pieces, and the discharge will be more gradual, resulting, it may be, in blowing the covers off the stove only.

Figure 113.