In the days of Imperial Rome there were, I suppose,

almost everywhere large communities of humble brickmakers, who made cheap bricks for poor folks' houses, and other sorts of obscure, but necessary, people; but Tacitus does not mention them, so far as I recollect. There are birds which fill a similar place in the feathered commonwealth. The Wren Warblers and Tree Warblers do an inestimable amount of useful work and appear to enjoy as large a measure of contentment and