Big Ben – The great bell which strikes the hours on the clock at Westminster.
Bizzle – A corruption of Bezel. See Bezel.
Blow Holes – Places where the brass and steel of a compensation balance are not perfectly united, when they are put together with silver or solder.
Bob – The metal mass forming the body of a pendulum.
Boethius, Ancius Manlius Severinus, A. D. 480-524 – A Roman philosopher and statesman to whom is sometimes attributed the invention of the clock. He did make a sun-dial and a water clock which latter may have contained a germ of the idea later developed into our modern clock.
Boss – A cylindrical prominence or stud. The minute hand is carried on the boss of the center wheel.
Bottom – Of a Watchcase – The cover outside the dome of the case. Commonly called the "back."
Bouchon – The hard brass tubing of which pivot holes in watch and clock plates are made; known commonly as "bushing wire." The short sections cut off for a pivot being called the "bushing."
Bow – The ring of a watch case to which the guard or chain is attached; also known as "pendant bow."
BOW AND BUTTON
Box Chronometer – A marine chronometer.
Boxing-In – Fitting the watch movement in its case; applied chiefly to the encasing of stem-winding movements.
Bréquet, Abraham Louis – A celebrated Swiss mechanician and watchmaker born at Neufchatel in 1747. He made several improvements in watches, the most notable being the Bréquet hairspring still in use in the best watches. He died in 1823.
BRÉQUET SPRING
Bréquet Spring – A form of balance spring which is a volute with its outer end bent up above the plane of the body of the spring and carried in a long curve towards the center near which it is fixed. Like all other springs in which the outer coil returns towards the center, it offers opportunities of obtaining isochronism by varying the character of the curves described by the outer coil and thus altering its resistance. So-called from its inventor, Abraham Louis Bréquet (q. v.). Its advantage over the flat spring is that the overcoil allows expansion and contraction in all directions, thereby avoiding a good deal of side friction on the pivots as well as insuring more nearly perfect isochronism in changes of temperature.
Bridge – A standard fastened to the plate, in which a pivot works.
Bridge Model – The term given to watch movements in which plates or bridges carrying the upper pivots of the train rest firmly on the lower or dial plate and are held rigid by steady pins on lower side of the plate; the bridge being secured direct to the dial plate by screws termed plate or bridge screws. This is the most common construction of present-day manufacture and is utilized in three-quarter plate or separate and combination bridges covering one or more pivots of train wheels. Its alternate is "pillar model."
Buck, D. A. A. – A watch repairer in Worcester, Mass., who designed a model for the Waterbury watch. His first model was not successful, but in 1877 he completed one which, a little later, the Waterbury Company, with Buck as master watchmaker, started to make. He remained with the company until 1884.
Bush – A perforated piece of metal let into a plate to receive the wear of pivots.
Butting – The engaging of the tips of the teeth of two wheels acting in gear. The proper point of contact being in the line of the shoulders of the teeth, butting is remedied by setting the wheels farther apart.
Button – The milled knob used for winding and setting a keyless watch.
Calculagraph – Trade name for a device for automatically computing and recording elapsed time in connection with factory jobs and other work where it is necessary to show the amount of labor used.
Calendar – A system of dividing the year into months and days. The principal calendars known to history are: the Julian calendar; the Gregorian calendar; the Hebrew calendar; the Mohammedan calendar; and the Republican calendar. None of them has been quite accurate in dividing up the solar year, and frequent arbitrary corrections are necessary to secure a practical approximation. See descriptive article under each title.
Julian– Established by Julius Caesar, 46 B. C., to remedy existing defects in the Roman calendar then in use. The Julian year was based on the assumption that the solar year is 365¼ days – which was 11 minutes and 14 seconds too long. The scheme adopted was to make the regular calendar year 365 days, and to add one day every fourth year. The Julian calendar is still in use by Russia and Greece, where the dates now differ from those of most other countries by 13 days.
Gregorian– Established October 15, 1582, by Pope Gregory XIII, in correction of the obvious errors of the Julian calendar. It is the calendar now in use by nearly all civilized nations. The mean length of the Gregorian year is 365 days, 5 hours, 49 minutes and 12 seconds – 26 seconds longer than the actual solar year. Correction is made by adding a 29th day for February every fourth year, excepting when the date of said fourth year is divisible by 100. If, however, the date is also divisible by 400, the extra day is added.
Republican– The calendar of the French Revolution (1793) declared to begin at midnight on the meridian of the Paris Observatory preceding the true autumnal equinox, September 22, 1792. There were 12 months of 30 days each and 5 or 6 "extra days" (as might be necessary) at the end of the year to bring the new year nearest to the then position of the equinox. Abolished January 1, 1806.
Hebrew– Composed of 12 lunar months, a thirteenth month being added from time to time to secure correspondence of the months with the passing seasons. The months are arbitrarily arranged to have alternately 29 days and 30 days. The length of the calendar year varies from 353 days to 385 days.
Mohammedan– Based on a lunar year of 354 days divided into 12 lunar months which are alternately 29 and 30 days in length. During each period of 30 years a total of 11 days are added one at a time at the end of a year. The lack of co-ordination with the solar year results in a total separation of the seasonal year and the calendar year. In use in Turkey and some other Mohammedan countries.
CALENDAR CLOCK
Calendar Clock, or Watch – A clock or watch which indicates days and months as well as hours.
Caliper – The scheme of arrangement of a watch train, or the disposition of the parts of a watch.
CAM
Cam – A rotating piece either non-circular or eccentric, used to convert rotary into linear reciprocating motion, oftener irregular in direction, rate, or time.
Cannon Pinion – The pinion to which the minute hand is attached. It is tubular in form (whence its name), the main arbor passing through it friction-tight.
Canton Berne – The Swiss district which does the largest export business in silver and base metal watches in Switzerland. The cantonal government has done everything possible to promote the industry, among other things: 1. Established information offices in the principal watch-making centers. 2. Established a permanent exhibition of articles used in the industry. 3. Established schools and associations and protective territories. 4. Prepared statistics and means for negotiating commercial relations.
Cap – The part of the case that covers the movement.
Capped Jewel – A jewel having a protective end-stone.
Carillon – Chimes frequently used in the earlier clocks for striking the hours. Still used in some clocks.
Caron, Peter Augustus – A famous Paris watchmaker, afterward called Beaumarchais, who made the first keyless watch of which we have any account.
Case – The metal box in which the movement of a watch is inclosed.
Case-Springs – The springs which cause the outer bottom of a watch case to fly open when the lock spring is released.
Center of Gyration – That point in which the whole mass of a rotating body might be concentrated without altering its moment of inertia.
Center of Oscillation – That point in a pendulum at which, if the whole mass of the pendulum were collected, the time of oscillation would be the same.
Center Seconds or Sweep Seconds – A long seconds hand moved from the center of a watch dial, as are the minute and hour hands.
Center Staff – The arbor attached to the center wheel which carries the minute hand.
Center Wheel – The wheel in ordinary clocks and watches placed in the center of the frame on whose arbor the minute hand is carried. It is intermediate between the barrel and the third wheel.
Chamfer – To cut away to a bevel the right angle formed by two adjacent faces as of a jewel or stone. It is also occasionally used to signify channeling or grooving.
CHAMFER
Chasing – A form of ornament for metals which is made by punching or pressing from behind to present the pattern in relief instead of by cutting away the material.
Chops – In a pendulum clock the blocks, usually of brass, between which the top of the pendulum suspension spring is clipped to prevent its twisting as it swings.