Melt the asphaltum, and add gradually to it the other two ingredients. Apply this with a small painter's brush, and leave it to become perfectly dry. The grate will need no other cleaning, but will merely require dusting every day, and occasionally brushing with a dry black-lead brush. This is, of course, when no fires are used. When they are required, the bars, cheeks, and back of the grate will need black-leading in the usual manner.