Walpi streets are the living rock of the mesa worn smooth by human feet and swept by the officious wind-god, whose dry air, with the aid of the sun, form the board of health of the Hopiland. This rocky surface must have been a great trial to the _kiva_ builders, as traditional custom requires that such meeting places of the secret societies or brotherhoods should be underground. The _kivas_ along the streets thus represent a great amount of work in their construction, and it is clear that, when the builders found a cleft in the rock or a niche in the cliff-edge, they appropriated it as the site of a _kiva_, then built an outer wall overhanging the precipice and prepared the deep oblong room with toilsome labor, for they had only the rude tools of the stone age. The two poles of the ladder project from the _kiva_ hatchway, and one may descend if no ceremony is on hand. There is not much to see except an empty, smoke-blackened room with stone-paved floor, plastered walls, and ceiling crossed by heavy beams. Just in front of the ladder is a fireplace, consisting of a stone box sunk in the floor, and the portion of the room back of the ladder is elevated. These subterranean chambers are now found in use only in Tusayan, where this manner of building them, along with many other ancient customs, has been preserved by the Hopi through many generations. Hopi houses are small, and as in the other pueblos of the Southwest, the first families live in the second story, which is reached by a ladder. In recent times, though, the ground floor, which formerly was used chiefly for storage, has been cleaned out, furnished with doors, and occupied as habitations. Steps on the dividing walls lead to the upper story and the roof forms a general loitering-place. The living room is kept in good order, and a goodly array of blankets, harness, and clothes hanging from a swinging pole are looked on with pride and complacency. In the granary, which is generally a back room, the ears of corn are often sorted by color and laid up in neat walls and one year's crop is always kept in reserve for a bad season. Red corn, yellow corn, white corn, blue corn, black corn, and mottled corn make a Hopi grain room a study in color. Three oblong hollowed stones or metates of graded fineness are sunk in the floor of every Hopi house, and on these, with another stone held in the hands, the corn is ground to fine meal, the grinders singing shrill songs at their back-breaking work. In the corner of the baking-room is a fireplace covered with a smoke hood and containing slabs of stone for the baking of _piki_, or paper bread, while scattered about are many baskets, jars, bowls, cups, and other utensils of pottery well fitted for the purposes of the Hopi culinary art. Outside the house is a sunken pit in which corn-pudding is baked.