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John Swain Chronograph, Bristol

Last updated, July 06

Manufacturer: ...John Swain & Co, Bristol & Warrington, 1882.

Dimensions:

Watch diameter.................58.4 mm
Movement Ø.............. ...... 49.6 mm
Thickness..........................19.2 mm
Total weight ......................158 g

Indications:... Minutes, hours and seconds. The watch hand can be stopped.

Movement: .No. 84200..Chronograph watch. Key wound and set from the back.
Chain and fusee. The center seconds wheel is an integrated part of the gear train. Split bimetallic balance with weight screws. Pointed tooth scape wheel with tangential lever. 17 jewels. Frequency is five swings per second.
The watch can be stopped by a slide button in the band at the two o'clock position . The slide acts via a lever and a pin toward the roller of the balance. In this way, the entire watch train is halted. The second hand can't be reset to zero.

Dial:......Enamel on brass, Labeled "CENTRE SECONS CORONOGRAPH". Three dial feet from copper, fixed by pins. Center sunk. Arabic numerals. Seconds indication divided into 300 1/5 increments.

Case: No. 84700. From sterling silver, London hallmarked <G>1882. J.H. probably the case maker. Hinged bezel, dust cover and back.

Fig. 1: Base plate. Note the concentric wheels for seconds, minutes and hours. Fig. 2: Top plate.
Fig. 3:
The Swain-Chronograph on a 5/10 millimeters grid. Note the slide button for stopping the second hand at the two o'clock position.
With this, not only the second hand is halted but the entire movement.

Remarks:.....Stop watches were frequently used from the very beginnings of the manufacture of pocket watches. When stopped, usually the entire train of the watch was halted. If not, you were the lucky proprietor of a rare stop watch with two independently acting movements, one for reading the time and the nother for useing as a stop watch.
Prior to the 20th century (introduction of the radio) the error caused by stoppting the watch for a short period of time was neglicible, since watches generally were adjusted by a sundial. That meant the time was accurate to within five minutes at best.
In 1844 the Austrian watchmaker Winnerl invented a heart-shaped cam that allowed the second hand to be reset to the zero position with a push button. That facitiated the reading of the elapsed time without halting the movement.
The chronograph, as we use it today, usually has a three action stop button, start - stop - reset, controlled by a ratchet and a castle-wheel. This was patented by the Swiss watchmaker A. Nicole in 1862. But, until about 1890, only stop watches such as the one introduced here were commonly in use.

What were stop watches used for? ...Certainly by doctors. They measured the pulse of their patients with them. And, according to Alan Shenton, "Pocket watches of the 19th and 20th century" (1995), also at horse races for rating the horses.