To remedy a leak at a boiler joint, take out the tap and put a new grummet or washer between the back nut and the boiler. To move the nut, it must be held by a large screw-hammer or spanner inside the boiler, while a similar tool must be used to turn round the tap outside. The new washer can be made of sheet rubber, or some yarn twisted into a ring, or a ring of cardboard soaked in water to make it soft. With the two latter red-ami white-lead (mixed to the consisteucy of very soft putty) must be used. A leak at the bottom nut of a boiler tap most probably indicates that the plug is worn and wants "re-grinding." Unscrew the nut and take out the plug. Then replace the plug, with a little flour emery and oil smeared on it, and twist it round and round evenly to grind the surfaces true to one another. To make a successful job, however, the grinding should be done in a lathe.