The Wire-and-Bristle Hairbrush: Steel Teeth With a Soft Border

"My invention relates to hair-brushes, and consists in constructing the same with a central section of fine steel-wire teeth, and surrounding said teeth with a border of bristles". "They have a projection a little greater than the wire teeth, and serve to guide the latter in their action upon the scalp, by reason of their sustaining a part of the pressure upon the brush by the hand of the user." Firey also claimed that such a brush "effectually cleanses the scalp" and is "invigorating to the scalp"; those are his claims, not tested here.

Draw an oval brush head about 9 cm by 6 cm with a handle on a hardwood board and cut it out with the coping saw. Sand it smooth. Mark a grid of about 40 holes in an oval in the middle of the head, and two rows of holes round it. Drill the middle holes to fit the wire snugly, about 1 cm deep; drill the border holes wider, for the tufts. Cut stainless steel wire into pins 3 cm long and file one end of each into a smooth dome. Glue them into the middle holes, domed end up, all standing the same height. Fold small bunches of boar bristles in half, dip the fold in glue and push them into the border holes. When the glue has set, trim the bristles so they stand about 3 mm higher than the wire teeth.

**Samuel M. Firey** of Clear Spring, Maryland, received US 106,680, dated 23 August 1870. His brush also had a second stock of ordinary bristles glued to its back, "which can be used when the other is not desired". **Honest limits.** The notebook treats the bristles as carrying a fixed share of the force; real bristles bend more the harder you press. Force, counts and tip size are examples.