W. H. Samelius, Chairman
Science of Horology and Technical Board
The Tourbillion, one of the many inventions of Breguet, was expected to lessen or do away with position error. It was constructed in such a way that the balance and entire escapement revolved within a cage several times during the hour.
Kidney-piece. A cam shaped like a kidney used in clocks to denote the difference between true and mean solar time.
Isochronism may be attained by reforming overcoil of hairspring, by increasing or decreasing the angle of draw on the pallets, by using a shorter or longer hairspring, by closing the regulator pins, by changing the mainspring.
A watch cannot show good rates when pivets are poorly polished, out of round, ends not flat or when pivots are not of equal size. When the balance hole jewels are of poor quality, too thick or too thin. Holes not concentric, jewels out of flat or cap jewels pitted. When the hairspring is poorly circled, out of center, out of flat or has uneven development.
When the regulating pins are too far apart. If the balance is magnetized, poorly fitted roller jewel or a rough fork slot, even if the escapement and train is in perfect order.
Many workmen, in replacing a balance staff. drive out the old staff from the balance wheel. Some turn off the staking before removing the staff, a still better plan is to turn down the hub of the staff so as to remove the staff from the lower side of the wheel. This method will save much time in trueing and poising the balance.
In order to adjust an escapement intelligently theory alone will not make a good workman. Practice without theory may do after a fashion. A thorough knowledge of the nature of its functions is essential and with theory and practice, the two united will go to make a rapid and skillful workman.
An 18-size mainspring, when wound, will lift about a one pound weight when suspended from a cord wound on a barrel and at the end of 24 hours a good mainspring should lift about 3/4 pound.
.00010 inch added to or deducted from the thickness of an 18-S hairspring makes a difference of approximately 6 minutes in time for 24 hours.
The Duplex escapement acquired its name from the fact that in original form it had two escape wheels, hence the application of the Latin word "Duplex." This escapement was invented by Dutertre, a French watchmaker, about 1750.
An adjusted watch is a watch that is in perfect order. Literally this is true for this is what "adjusted" means what it attempts to secure.
The word "adjusted" is derived from Latin "ad justus," meaning just right.
When a watch is "just right" it is what we call a naturally adjusted watch and needs no adjustments by the adjuster.
The balance hole jewel and the cap jewel should be from .01 mm. to .02 mm. apart. When the upper side of the hole jewel is convex, capillary attraction will hold the oil around the pivot until the last atom of oil is exhausted.