To avoid this the top bar should never be less than five-eighths inch to three-fourths inch thick, while for long top bars seven-eighths-inch or 1-inch strips are preferable. The side and bottom bars may be made of one-fourth-inch strips. A corner is taken from the end of the top bar by a cross cut made at exactly right angles on the underside of the top bar, reaching to within one-fourth inch of the top of the bar, and another cut from the end so as to meet the first-mentioned one. Each side bar can then be nailed by one nail driven from above through the top bar, and two driven through the side bar itself into the end of the top bar. The bottom bar can then be nailed on, or, better still, cut short enough to permit it to be inserted between the side bars, the nails holding it to be driven through the latter. Nailing frames loosely or without getting them exactly in true brings with it great disadvantages. If only slightly out of shape they may swing together at the bottom or touch the sides of the hive, and in either case will be glued fast by the bees; also in the first instance the combs, which are always built perpendicularly, will not be wholly within the frames. To avoid these troubles it is essential, first, that the parts for the frames be cut very accurately; second, that the frame be in exact shape at the time of nailing; and third, that the nails be driven in quite firmly; long, slender, flat-headed wire nails being necessary to secure proper stiffness of the frame. Nails 1½ to 1¾ inches long made of No. 16 or No, 17 wire, or 4d. fine wire nails are the right size. Nailing in a form, such as is shown by fig. 25, is therefore advisable. Greater ease in withdrawing the frames from the hive is secured by making the bottom of the frame one-fourth inch less in width than the upper part. A round-headed nail or a curved wire staple driven through the side bar at each lower corner into the end of the bottom bar and left projecting one fourth inch will also facilitate the removal of frames and their insertion in the hive without the crushing of bees, and hence allow more rapid manipulation. (Fig. 24, _pn_.) [Illustration: Fig. 26.--Lock-joint chaff hive. (From Gleanings in Bee Culture.)] [Illustration: Fig. 27.--Manner of nailing hives. (Original.)]