Phonograph "gramophones" or "talking-machines". His "gramophone record" was the first disc record to be offered to the public. They were five inches (12.7 cm) in diameter and recorded on one side only. Seven-inch (17.5 cm) records followed in 1895. Also in 1895 Berliner replaced the hard rubber used to make the discs with a shellac compound. Berliner's early records had poor sound quality, however. Work by Eldridge R. Johnson improved the sound fidelity to a point where it was as good as the cylinder. By 1901, ten-inch (25 cm) records were marketed by Johnson and Berliner's Victor Talking Machine Company, and
Gear inches which has a nominal cross-section of 23 mm. 700c wheels have a rim diameter of 622 mm. Hence the wheel diameter is (2 × 23 mm) + 622 mm = 668 mm which is equal to 26.3 inches (rounded to 1 decimal place). 26 inch mountain bicycle wheels have a rim diameter of 559 mm. This ignores factors that contribute to the actual rolling radius of the tyre and rim together: the vertical deflection of the tire above the contact patch and the difference between the manufacturer's stated size and the actual tire radius when mounted and inflated. Gear inches,