From The American Horologist magazine, April, 1936
W. H. Samelius, Chairman
Science of Horology and Technical Board
The first really portable watch or clock was made by Peter Henlein, a young blacksmith, of Nuremberg about 1504. It was made entirely of iron, spring driven, the dial of the watch was about six inches. Timepieces were usually carried by shoulderstrap or handle.
The Waterbury Watch Company in the early days used the Duplex Escapement in their watches.
That the mainspring in the early Waterbury watches were nine feet long.
The Hamilton Watch Company was founded in Lancaster, Pa., in 1892.
Our first wheel-cutting machine was invented by Dr. Robert Hooke of England.
Second hands on clocks were first used by Tompion of England about 1676.
The Greenwich Observatory at England was founded in 1675 for promotion of astronomy and navigation.
That the overcoil hairspring was introduced by Abraham Louis Breguet about 1775.
That adjusting a pocket watch for temperature errors, the corrections are made by relocating the· balance screws closer or farther away from the cut end of the balance wheel rim.
In the marine chronometer adjustments for temperature errors are made by sliding a weight which is attached to the rim of the balance wheel.
In some of the finest cylinder escapements, the cylinder was made of ruby.
The cylinder and duplex escapements are known as frictional escapements.