On attic roofs, and where only one side of the house can be used for the attachment of rain-water pipes, the water from one side is brought across the roof by means of a “box” gutter of wood, lined at the bottom and sides with lead or zinc, and covered with a board. This often emits a very foul smell, owing to the accumulation of decaying matter. When such guttering cannot be avoided, it should occasionally—say once a week—be carefully cleaned out. The same matters will sometimes silt up and stop the gullies, shown at the foot of the rain-water pipes, hence it is equally necessary to see that these traps are cleaned out, say monthly.