This fine clock is perhaps one of the most interesting in my collection.
The serial number is 1287 with a date of 6/12/1912
It has been said that Gents started their serial number series with the number 1000 which would make this a very early clock.
Movement: The movement is basically very similar to that of later clocks but there are many variations of detail. In particular, at this early date, the name Pul-syn-etic was not in use and the casting is marked "The B-P Patent system" with the patent numbers along the base of the casting.
Case: Overall dimensions 52.25" x 13.25" x 8". The case is of oak, finished light oak colour and is different in construction to later clocks, this one being comb jointed at the corners with further timber screwed to top and bottom having projecting moulded edges at sides and front. The glazed door has mitred joints, unlike later models which all have square cut corner joints. The lock was fitted to the side of the case with the keep plate on the door
Dial: a 6.5" diameter circular pilot dial is fitted to the door. This is the original and is discoloured but I prefer to retain it rather than fit a replacement. The lettering is now incomplete but reads "Gent & Co. Ltd., Makers," and "Leicester" Historical note: The history of Gents has been related by D J Bird in great detail (see below) but in brief:
The first Gents transmitter (as they were then called) was made in 1905 and installed in Thornbridge Hall so that pattern of clock came to be called the Thornbridge though Gents labelled them types C1 to C4.
The design was simplified and became known as the Tompion transmitter (C5) this carries the story to 1907.
The design was further simplified and a new patent obtained in 1907. This was regarded as a cheap construction method and enabled Gents to sell more cheaply so production, which commenced in 1908, concentrated on this design. By 1909 it was called the Home transmitter and known as C6 if it had no pilot dial or C7 with a dial.
The C7 developed as follows:
In 1909 the main contacts were only about 1.75 inches below the lower pivot. By 1915 the armature and switch lever were an inch longer and there were other detail alterations. The pendulum rod in early clocks was usually of teak moving between two pins on the crutch. The spark quench if fitted, was a single large capacitor across the movement terminals.
After the 1914-1918 war several alterations were made one after the other. The main casting was extended at the top so the movement could more firmly fixed by being screwed through holes in the casting to the wall.
Early models of the C7 had "THE B-P PATENT SYSTEM" cast in the main casting and patent dates etc along the lower edge.
Around serial 1850 the lettering on the casting was changed to "PULSYNETIC ELECTRIC SYSTEM" and soon after the casting was extended at lower left side to provide a lower backstop support for the armature.
The next feature to be introduced was a separate pendulum support casting, first offered as an optional feature. One clock so fitted being number 1977
Returning to this particular clock, serial number 1287, points to note are:
It has the single large spark quench capacitor near the top of the case.
The main casting is the original shape, not extended at the bottom left.
Invar pendulums came into use quite early and one is fitted to No.1287
The printed label giving date and serial number is of a different form and is on the back of the door.
The serial number is stamped into the top rail of the case (as usual with Gents) but is also stamped into the hidden face of the bearing plate for the gravity arm.
The earliest clocks had crutch and gravity levers made from brass strip and contacts only about 1.75 inches below the gravity arm pivot. One of the first major changes was the introduction of castings for the gravity arm and crutch lever and the extension of the arms for the main contact to about 2.75 inches below the pivot of the gravity arm. No. 1287 incorporates these changes.
According to D.J.Bird the early clocks, up to about serial 2317, did not have a guard to the crutch to control the action of the gun lever. No.1287 is fitted with a guard, but whether this was a later addition or original I do not know.
One odd feature that I have not seen before is the presence on the top of the case of two brass strips set close to each other and with serrated edges. Each has a screw terminal. There were once upon a time wires from these strips to the movement but they have been cut just inside the case so I do not know how they were connected, nor their purpose. They look for all the world like a spark gap ! Click here for picture.
The pilot dial has the "Parsons Patent" Mark I movement. This was at one time fitted with additional wheels and contacts as can be seen from the pictures, but the contacts have been removed and I have not yet ascertained their purpose.
All collectors of Gents electric clocks are deeply indebted to D J Bird who has written extensively on the C7 and other Gents clocks. Much of the information in these notes is derived directly or indirectly from that source and is gratefully acknowledged. Collectors are advised to join the electrical horology group of the AHS in order to benefit the detailed information available from the AHS.
