Stones are gathered from the sides of the mesa not far away, those not larger than a moderate burden being selected. The sand-rock of the mesa is soft and with a hammer-stone convenient masses may be broken off. At present there is a quarry on the Walpi mesa; the blocks gotten out by means of axes are more regular than those in the old houses, which show little or no traces of working. Between the layers of rock are beds of clay which require only moistening with water to become ready for the mason. The architect has paced off the ground and determined the dimensions of the house, giving the arm measurement of the timbers to the logging party who, with the rest, have got the materials ready. The next step is to find the house-chief and secure from him four eagle-feather prayer-plumes. These are deposited under the four corner stones with appropriate ceremony of breath-prayers for the welfare of the house and its occupants. The plumes are dedicated to the god of the underworld, the sun, and other deities concerned with house-life. The builder then determines where the door shall be and places an offering of food on either side of it; he then walks around the site from left to right, sprinkling a mixture of _piki_ crumbs and other food with tobacco along the line of the walls, singing to the sun his _kitdauwi_, "house song"; _Si-si, a-hai, si-si, a-hai_, the meaning of which has long been forgotten. The walls are laid in irregular courses, mortar being sparingly used. The addition of plastering to the outside and inside of the house awaits some future time, though sometimes work on the outside coat is put off to an ever vanishing _mañana_. When the house walls, seven or eight feet in height and of irregular thickness from seventeen to twenty-two inches are completed, the women begin on the roof. The beams are laid across the side walls at intervals of two feet; above these and parallel with the side walls are laid poles; across these is placed a layer of rods or willow brush, and above this is piled grass or small twigs. A layer of mud comes next, and when this is dry, earth is placed on it and tramped down until hard. The roof, which is complicated and ingenious, is nearly level, but provision is made for carrying off the water by means of spouts.