The Ear-Mufflers: A Steel Spring Over the Head and a Pad on Each Ear

"My invention relates to that class of ear-mufflers which are kept in contact with the ears by means of a spring, which forms the body, and also connects the pads of the muffler". "A represents the body of the muffler, which consists of a flattened metallic spring, semicircular in shape, and having its ends bent or overlapped, and riveted down, as seen at d, to form portions of the joints B. The frame of the pad F consists of a single piece of wire, C, having its ends joined at D and bent into an oval shape". "The frame C is covered with cloth, and may be also lined or covered with fur, wool, skin, or any other fibrous non-conductor of heat, as desired." "In the use of my improvement the body A is passed over the top of the head of the wearer, as seen in Fig. 2, its contractile action causing the pads F to press firmly against the ears, and protect them from cold".

Bend a spring steel strip into a half circle that fits over your head with the ends about 3 cm closer together than your head is wide. Wear gloves and eye protection; file the ends smooth. Bend two ovals of stiff wire to cover an ear, cover them in wool felt and stitch them on, and fix one to each end of the band. To test a pad without a head: fill two identical glass bottles with water at 40 C. Wrap one in a single layer of the felt. Stand both 1 m in front of a fan and read their temperatures with a kitchen thermometer every two minutes for twenty minutes. Plot both; the bare bottle is the bare ear.

**Chester Greenwood** of Farmington, Maine, filed US 188,292 on 8 February 1877; it is dated 13 March 1877. His claim covers the elastic metallic body with pads whose wire frames have bends that stop them swinging too far. **Honest limits.** The patent gives no sizes or spring strength. Ear area, air-film coefficients, pad conductivity and spring stiffness in the notebook are examples; the bottle test is the measurement.