consisting of five tuning forks for speeds 60mph (439.4Hz), 50 (366.2), 40 (293), 30 (219.7) and 20 (146.5) with striking block, in fitted case. Also included a Test Report from the National Physical Laboratory dated 10th December 1957 stating the measured frequency of the five forks; Tuning Fork Used To Tune The Ships Bell On HMS Sheffield Town class cruiser commissioned in 1937 and took part in action against the Bismarck (1941), the fork is stamped 'Old Philharmonic' and 'C#', mounted on card with label 'The Stainless Steel Ship's Bell On HM Cruiser "Sheffield" Was Tuned To This Fork In 1937' 5 3/4", 14cm long; together with a large quantity of assorted Tuning Forks by Ragg Tuning Forks Ltd and three Catalogues (qty)

A collection of vintage tuning forks from the archive of the original Ragg family owners. Tuning forks are generally associated with music as they originated for that purpose in the early 18^th Century although they have been adapted over subsequent years for many different scientific and medical applications including sound therapy. The Ragg family commenced manufacture of tuning forks in Sheffield in 1840 and became the sole UK producer in the early 20^th century. The collection in the auction includes tuning forks manufactured for a wide variety of specialist uses over many years up to the 1970’s. Particularly interesting applications include a set of tuning forks from the 1950’s for checking early police speed “radars” (roadside speed cameras nowadays) and a variety of vintage and specialist forks for medical and scientific applications including a “stroboscope” fork for checking Post Office telex calibration.