23 Jewel Illinois Bunn Special Railroad Pocket Watch

23 Jewel Illinois Bunn Special Railroad Pocket Watch

23 Jewel Illinois Bunn Special Railroad Pocket Watch

23 Jewel Illinois Bunn Special Railroad Pocket Watch


1 available for immediate delivery

Product Details

Illinois 23-Jewel Envious 18-Size “Bunn Special” Railroad Pocket Watch in Very Collectible Collection
U.S.; Illinois; Man’s; Serial# 2,069,552; C. 1908
CASE: The yellow gold-filled, 18-size, plain polished case has an open face and is signed “Philadelphia Watch Case Co. – Victory”.
DIAL: This white porcelain, double sunk dial displays Arabic Gothic hour numerals, red Arabic 5-minute markers, subsidiary seconds dial and spade hands.
MOVT: This 23-jewel, lever-set movement with lever escapement is nickel with a full plate layout and is signed “Bunn Special – Springfield, Ill”. Marked “Bunn Special Springfield Ill., Adjusted Temperature & 6 Positions, Isochronism, 23 Ruby Jewels, 2069552, Double Roller”.
C 3 (The case is in very good condition)
D 3-44-46-53 (The dial is in very good condition, two hairlines, chip(s) or hairline(s) under the bezel, not visible when closed)
M 3 (The movement is in very good condition)  EA

Stem-wind, Lever-Set Movements
Mandatory for all railroad watches after roughly 1908, this kind of pocket watch was set by opening the crystal and bezel and pulling out the setting-lever (most hunter cases have levers accessible without removing the crystal or bezel), which was generally found at either the 10 or 2 o'clock positions on open-faced watches, and at 5:00 on hunting cased watches. Once the lever was pulled out, the crown could be turned to set the time. The lever was then pushed back in and the crystal and bezel were closed over the dial again. This method of time setting on pocket watches was preferred by American and Canadian railroads, as lever setting watches make accidental time changes impossible. After 1908, lever setting was generally required for new watches entering service on American railroads.

Lever Escapement
An escapement is a device in mechanical watches and clocks that transfers energy to the timekeeping element (the "impulse action") and allows the number of its oscillations to be counted (the "locking action"). The impulse action transfers energy to the clock's timekeeping element (usually a pendulum or balance wheel) to replace the energy lost to friction during its cycle and keep the timekeeper oscillating. The escapement is driven by force from a coiled spring or a suspended weight, transmitted through the timepiece's gear train. Each swing of the pendulum or balance wheel releases a tooth of the escapement's escape wheel gear, allowing the clock's gear train to advance or "escape" by a fixed amount. This regular periodic advancement moves the clock's hands forward at a steady rate. At the same time the tooth gives the timekeeping element a push, before another tooth catches on the escapement's pallet, returning the escapement to its "locked" state. The sudden stopping of the escapement's tooth is what generates the characteristic "ticking" sound heard in operating mechanical clocks and watches.

Watch adjustment is the process of correcting those errors in the watch that cause variation in time keeping. These include temperature influences, variation in driving power and position of the watch with respect to mechanism such as pendant up or dial up.

Watches with better calibre movements will have been adjusted at the factory for a number of positions. The usual array of positions include a subset of the following positions:
1. Dial up 2. Dial down 3. Bow up 4. Bow down (Not required by Railroad) 5. Bow left 6. Bow right

These positional adjustments are intended to insure that the watch is just as reliable and accurate regardless of the position in which it is stored or used.

In addition to positional adjustments, the watch may also be adjusted for Temperature(heat/cold). Temperature affects different elements in different ways. Heat will cause some metals to expand faster than others, and cold may cause some metals to contract more than others. A watch that is adjusted to temperatures will usually include some combination of metals that allow the watch to maintain its proper functionality within a larger range of temperatures than one that is not adjusted for temperature.

Another type of adjustment is Isochronism. As a typical watch spring unwinds the pressure it exerts on the wheels of the movement reduces. This has the potential to create a difference in the operating speed of a fully wound watch versus the same watch in an nearly fully unwound state. Adjustments for isochronism attempt to compensate for this potential by maintaining the same pressure from the spring throughout most of the operating range of the watch. This sort of adjustment was generally seen only on the finest railroad grade watches of the 20th century.

The general rule of thumb with adjustments is that more is better. However, for average every day use, a typical unadjusted watch was perfectly adequate.