The tangible things come first, in some such evidence as that provided by Government investigation, in the Blue Book bearing a forbidding title, the “Cost of Living of the Working Classes.” It shows them, gathered into astonishing cities, working for variable wage. It reveals the dwellings which they seek to transform into homes. It follows their wages from production to distribution, in the cost of their daily economy, the manner in which they divide up their exiguous incomes, the amounts they think it worth while to allot to shelter, to food, and to pleasure. It analyses over a thousand “family budgets,” each giving details of how much is spent weekly on butter, tapioca, or treacle. It shows the rate of birth and the rate of death: varying from city to city, both materially changing. It gives, in fact, in outline only, that blurred image of a huge and industrial population whose complete apprehension would furnish the key to many of the pressing problems of to-day. Here are the houses in which for a season they abide; in part the product of their own volition, in part the creation of external changes which they can but little control. They have had no choice in these constructions. Their demands and desires have scarcely counted in the provision made for them. Their impetuous need was shelter: shelter “on the spot,” around the sites of the new factories which had sucked them up from the deserted countryside. And they were thankful to take what was offered them by those men who foresaw the changes which were coming, and could accumulate fortunes in the rapid provision of immediate necessities. Swept into aggregations by the demand of the newest industries, the clay and stone has been hastily fashioned into place for human habitation. And now these stand to-day, made by, and yet making, the temper and characteristic of the people. Here the normal standard is a four-roomed cottage; there, “back to back” houses ravage the health of their inhabitants; here again huge piles of tenements encompass the bewildered occupants in a kind of human ant-heap; there the ancient dwelling of the wealthy or comfortable classes have been “swarmed out” by the busy people. Carlyle pictured mankind flowing, as it were, through the visible arena of material things. A wave of humanity beats through these solid constructions; it vanishes, another succeeds. “Orpheus built the walls of Thebes by the mere sound of his lyre. Who built these walls of Weissnichtwo, summoning out all the sandstone rocks to dance and shape themselves into Doric and Ionic pillars, squared ashlar houses, and noble streets?” All cities are thus built “to music.” What discordant melody to-day is responsible for the creation of Jarrow, or Salford, or Canning Town?