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拍品专文
The present clock is one of only perhaps ten finished examples made by William Hamilton Shortt between 1910 and approximately 1922. In 1910 Shortt had been befriended by Frank Hope-Jones who was then the greatest exponent of electrical horology and the co-patentee of the Cunynghame-Hope-Jones detached gravity Synchronome switch (1907).
Hope-Jones wrote of their relationship; Mr. Shortt took up horology in that year and accepted as its then greatest achievement and highest exposition of the art the Synchronome-Cunynghame escapement below the bob, with impulse and contact at every other second. His (Shortt's) experimental work was based upon it, and his scientific research was devoted to ascertaining its faults and curing them.
One of Shortt's key alterations was to substitute a wheel for the triangle at the bottom of the pendulum and adjusting the gravity arm. The latter also had a problem owing to its large moment of inertia and slow acceleration due to gravity relative to the speed of the pendulum. The present clock and, the few other prototypes, were each tried out on responsible jobs but they never excelled the performance of a standard Synchronome Master clock.
Shortt spent nearly ten years experimenting and improving the system interrupted only by the First World War when Shortt was at the Front but fortunately returned to work in 1916. Further experimentation led him discover that the now lighter lever was resulting in unsafe locking which meant the pivot friction was too variable and there was insufficient mass to ensure a good switch. This led Shortt to disassociate from the two functions of impulsing and switching and to provide a seperate lever for each, a light one to give impulse and a heavy one to make contact. This was tried out both below the bob and near the top of the pendulum. In its latter form it was put to test on the now famous experiment in the Edinburgh Observatory in 1922.
These extremely rare experimental working clocks are outlined and discussed by Hope-Jones in his Electrical Timekeeping but also in Shortt's own lectures.
Hope-Jones wrote of their relationship; Mr. Shortt took up horology in that year and accepted as its then greatest achievement and highest exposition of the art the Synchronome-Cunynghame escapement below the bob, with impulse and contact at every other second. His (Shortt's) experimental work was based upon it, and his scientific research was devoted to ascertaining its faults and curing them.
One of Shortt's key alterations was to substitute a wheel for the triangle at the bottom of the pendulum and adjusting the gravity arm. The latter also had a problem owing to its large moment of inertia and slow acceleration due to gravity relative to the speed of the pendulum. The present clock and, the few other prototypes, were each tried out on responsible jobs but they never excelled the performance of a standard Synchronome Master clock.
Shortt spent nearly ten years experimenting and improving the system interrupted only by the First World War when Shortt was at the Front but fortunately returned to work in 1916. Further experimentation led him discover that the now lighter lever was resulting in unsafe locking which meant the pivot friction was too variable and there was insufficient mass to ensure a good switch. This led Shortt to disassociate from the two functions of impulsing and switching and to provide a seperate lever for each, a light one to give impulse and a heavy one to make contact. This was tried out both below the bob and near the top of the pendulum. In its latter form it was put to test on the now famous experiment in the Edinburgh Observatory in 1922.
These extremely rare experimental working clocks are outlined and discussed by Hope-Jones in his Electrical Timekeeping but also in Shortt's own lectures.