Shortt free-pendulum clock regulator parts
Date: circa 1929
Inventory Number: 1998-1-0187d
Classification: Clock
Dimensions:blue board box: 8.5 × 37.5 × 25.2 cm (3 3/8 × 14 3/4 × 9 15/16 in.)
DescriptionMiscellaneous parts for the Shortt regulator which were formerly held in wooden case (1998-1-0187c). These include:
--Spare pendulum suspension springs stored in a glass test tube with a cork stopper. The springs are milled from a solid piece of metal. 2 complete; 1 broken in two. They have some rust.
--A very tiny cylindrical clamp (?) apparently with a tightening screw, stored in a small glass test tube with a cork stopper.
--A shop-made wooden box to hold and protect a pendulum suspension spring. The box has a clamping block and has been marked in pencil, "OPEN THIS SIDE / CARE / F.P. Suspension / CARE"
--Metal shims and brass pieces to fit the clamping frame at the bottom of the vacuum chamber, when used with assorted experiments at Harvard.
--Two identical 33-cm rods of solid brass, each with a long brass screw embedded in one end.
--A short, bent, hollow length of copper tubing.
--A loose black knob
--A broken thermometer
--An unidentified tool with a wooden handle
--Some sort of electrical bridge (?) cut from whatever circuit to which it had been attached. One component is a coil, perhaps a transformer. Two heavy insulated wires leading to it have been cut. The thin rectangular part on the top is a Dubilier condenser, stamped with the Dubilier logo and marked "PAT. 1345754"
Previously this also contained a vacuum gauge and a microscope, which were removed and attached to the Shortt clock in March 2008.
Historical AttributesThis clock was set up in Harvard University's Institute of Geographical Exploration at 2 Divinity Avenue, Cambridge.
Primary SourcesSynchronome Company Ltd, copies of 9 patent drawings related to the clock movement, electrical circuitry, and more. In instrument file.
Synchronome Company, Ltd., "Instructions for the Erection of Free Pendulum, Master and Slave Clocks," circa 1959. Typescript in instrument file.
Synchronome Company, Ltd., "Memorandum on the Microscope and Special Beat Plate," circa 1959. Typescript in instrument file.
F. Hope-Jones, "The Free Pendulum," a lecture delivered before the British Horological Institute on April 19th, 1923 (London: The Synchronome Company, Ltd, [circa 1923]). Booklet in instrument file.
F. Hope-Jones, "The Free Pendulum," Journal of the Royal Society of Arts 72 (1924): 445-462. Offprint in instrument file.
Synchronome Company, Ltd, Astronomical Regulators and Observatory Time Installations, Together with a Brief Essay on the Free Pendulum and the General Principles of the Synchronome System on which It Is Based (Mount Pleasant, Alperton, Middlesex, UK: The Synchronome Company Ltd, [circa 1950]). Booklet in instrument file.