1660 - Calendar movements were introduced to English longcase clocks. The first American patent issued for a calendar movement was in 1853.
1663 - Minute hands were introduced to longcase clocks.
1745 - Phases of the moon were introduced on clock dials .
1775 - Up until 1820, only hour hands were used in clocks. In 1775, matching minute and hour were introduced.
1780 - Second hands began to be added to longcase clock dials.
1785 - Dots in the minute rings of brass dials were added
1792 - Paper clock dials were introduced and applied to a wooden or metal backing.
1800 - Painted dials came into general use on clock faces.
1800 - Reverse-painted glass tablets date from the early 1800's.
1806 - Machine made wood screws were introduced in France as early as 1806.
1820 - Wooden movements were generally used in early American shelf clocks until around 1820. Up until then hand cast and finished brass movements were very expensive. Chauncy Jerome began manufacturing cheap 30-hour brass movements in the 1830’s; by the early 1840’s brass movements virtually replaced wooden ones.
1836 - Gold electroplating was used to provide a safe alternative to the hazardous use of mercury in gilding metals, which was banned in 1799.
1840 - Coiled wire gongs were used in English bracket (shelf) clocks.
1869 - Celluloid was patented. Adamantine celluloid veneer was patented in 1880.
1882 - Clock models in Adamantine veneer finishes which mimicked marble, slate, wood and other materials were introduced by Seth Thomas.
1890 - Chime bars, also known as chime rods, were introduced to clocks. These metal rods are specially tuned to produce a sequence of chime notes when struck by the movement's chime hammers.
1896 - It is required that the country of origin be mark on the clocks that are imported into the United States.
1901 - The Anniversary trademark on 400-Day clocks was introduced.
1905 - Plywood was first used.
1910 - An early inflammable, mouldable plastic, called Bakelite was invented.
Signatures on an antique clocks dial or movement can sometimes help to date a clock if you can find the clockmakers name and the date of activity listed in one of the many guides accessible to watch and clockmakers.
However, a signature may refer to someone other than the clockmaker. 19th century retailers and distributors often put their own names on clocks as an attempt to brand their product. The actual clock movement may have been made by someone else, as until the 19th century clock cases were almost always made separately from the movement and were rarely signed. And, of course, a signature may be fraudulently added as an attempt to increase an antique clocks value.
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