less doors with cross-tie (C.T.) serving as door stop. Illus. 20 shows top strip (T.S.) serving as door stop, with the drop nail (DN) type of top construction. In hingeless door use, the door fastener (D.F.) is installed at the top, and a door channel strip (D.C.St.) is used at the bottom. Such a strip 1⁄2x11⁄2x21 is nailed on the
front of the door sill (D.S.) as in Illus. 21 and 22. This provides a channel 1⁄2-inch deep (C), in Illus. 21, for the door to rest as in Illus. 22. The guard board (GB) prevents the bottom of door sliding into the pen. If guard board is not used, staples or nails may be driven into sides and partition about one inch above floor so that closed door may rest against the nails as (N) in right pen in Illus. 20. Hingeless doors may be either wire on wood frame, or all wood (one piece
—32—
