PREVENTING ACCUMULATION OF MUD IN BOILERS.
Mud-drums, with blow-off cocks attached, serve to check the growth of this evil when the engineer is careful to make frequent use of these appliances; and a strong pressure of washing-out water, poured frequently through the boiler, has an excellent cleansing effect: but some kinds of scale defy mud-drums and the best methods of washing out, leaving the only resort to be the removal of flues for cleansing. The filling up of a boiler with scale and mud, so as to prevent the engine from steaming freely, is necessarily a gradual process; and an observant engineer has time to note the change, and recommend the proper remedy.