Once again there were many entries, but the mystery object in Watch Around 008
proved a tough nut to crack. A large number of answers were way off the mark. It is in
fact a table-roller extractor, used for removing the disc of the table roller from the
balance staff. The tool is held vertically in a vice, and the balance is placed on the jaws
with the roller just beneath them. A tap on the balance staff with a hollow punch
separates the roller from the balance.
After an easy run of mystery objects, the tool in Watch Around 007 certainly took you aback. However, some of you correctly identified it as a tool for screws. It’s in fact a screw chuck. The screw at the end of a runner is inserted into the steel tube so that its head is flush with the steel plate. It can then be levelled, polished or slotted. Although intended for screw-heads it can be used to work on a variety of similar sized components.
Watch Around 006: In the last issue of Watch Around, the mystery object was perhaps too easy to identify. At
least 50 readers recognised it as a tool to remove the cannon pinion. In the old days the
centre-wheel was delivered with the cannon pinion, which drives the under-dial work. The
snap-on cannon was fitted friction tight on the centre-wheel arbor to allow the hands to be
set. Before assembling the watch, it was difficult to separate the two without damaging the
brass spokes of the wheel. With the grooved claw inserted between the centre-wheel’s steel
pinion and the underside of the cannon, pressing the lever separated the two parts easily and
without damage. The job would be impossible with pliers or a hand-extracting tool, since
they cannot get a grip on a solid part of the wheel.
If the mystery object in our last issue, Watch Around 005, baffled you, you can blame it on our watchmaker friends who said that our quizzes were child’s play. We really ought to make them more difficult, they declared. Well, we took their advice and the result is that only two readers came up with an acceptable, although not totally correct, answer. The notion that it had something to do with cutting the impulse face of the pallet so as to adjust its lift, was on the right track. In fact the impulse face is never recut by watchmakers. The tool is used to hold the pallet so that its depth can be fine-tuned by adjusting its length.
The mystery object in our last issue, Watch Around 004, is a roasting pan to turn screws blue or to let down their temper. Screws of different dimensions are inserted in the matching holes and the pan is jiggled over a flame until the right shade of blue is reached. Some readers called it a bluing pan, which is a general term for a rimmed pan on which a variety of objects can be tempered. Many others thought it could be for bluing pallet levers or for melting the glue holding the pallet stones so they can be adjusted. Notwithstanding the fact that tools might be used for purposes other than their primary intention, the right answer is that this bluing or tempering pan is specifically made for screws.
The mystery object in our last issue (Watch Around 003 p. 82) is called a rounding up
tool or a topping tool. Dating from the 1920s, it was used to reshape the teeth of a
wheel-blank. Watchmakers used this tool to adjust the profile of the teeth or reduce the
wheel’s diameter to ensure perfect gearing. Made redundant by modern wheel-cutting
methods, the rounding-up tool is now confined to restoration work.
The mystery object in our last issue (Watch Around 002, p. 82) is called
a “vibrating tool” and it compares the vibrations of a balance-wheel with those of a
standard balance, vibrating at a set frequency. The two superimposed balances are
started simultaneously.
The rate of the balance can be adjusted by changing the effective length of its spring until
it matches the frequency of the machine’s balance.
This delightful apparatus, dating from the mid 19th century, was photographed in the
workshops of Frédéric Aeschlimann, a veteran watchmaker of La Chaux-de-Fonds, who
is still devoted to the restoration of old clocks.
The mystery object presented
in Watch Around 001 (p 114) bears a name that simply describes its function:
upright drilling accessory.
Pictured in the workshop of Philippe Dufour in Le Solliat (Joux valley), the upright drilling accessory is
no longer widely used by watchmakers. It has been replaced by the jig-boring machine.
A few specific details on its use. The three ‘dogs’ or jaws clamp the bridge or plate to the base. The
vertical support holds a runner, each end of which is used alternately for centring and for drilling the hole.
Once the centring has been done, the runner is turned over. A bow-drill is fitted to the end to make the hole.