Fig. 32.
Fig. 33.
Fig. 34.
Fig. 35.
Fig. 36.
Cornish boilers are often altered to the plain cylindrical form, without compensation being made for the loss of strength caused by the removal of the tube; this has led to such explosions as shown in [Fig. 33], [No. 47, 1869], where two tubes where taken out, and [Fig. 34], [No. 42, 1867], where one tube was taken out. One of the most frequent and serious causes of loss of strength is the repairing of externally fired boilers. Not only are the patches sometimes only bolted on in a temporary manner, as in [Fig. 35], [No. 29, 1869], but even where they are rivetted on there is an entire want of bond or crossed joint, as in the case of the exploded boilers shown in [Fig. 15], [Fig. 16], and [Fig. 17], see page 70 and 71, [No. 10, 1869], and [Fig. 36.]