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November 1917 ad for an Ingersoll "Radiolite" watch, one of the first watches mass marketed in the USA featuring a radium-illuminated dial. Radium was discovered by Marie and Pierre Curie in 1898 [1] and was soon combined with paint to make luminescent paint, which was applied to clocks, airplane instruments, and the like, to be able to read them in the dark.
The Radium Girls were female factory workers who contracted radiation poisoning from painting radium dials – watch dials and hands with self-luminous paint. The incidents occurred at three factories in the United States: one in Orange, New Jersey , beginning around 1917; one in Ottawa, Illinois , beginning in the early 1920s; and one in ...
A modern watchmaker at his workstation; he wears a magnifying loupe to more easily see the small parts of a watch A watchmaker's lathe in use to prepare a decorative watch component cut from copper. A watchmaker is an artisan who makes and repairs watches. Since a majority of watches are now factory-made, most modern watchmakers only repair ...
Thomas Mudge, inventor of the lever escapement. The lever escapement, invented by Thomas Mudge in 1754 [18] and improved by Josiah Emery in 1785, gradually came into use from about 1800 onwards, chiefly in Britain; it was also adopted by Abraham-Louis Breguet, but Swiss watchmakers (who by now were the chief suppliers of watches to most of Europe) mostly adhered to the cylinder until the 1860s.
Because of its relative longevity, 226 Ra is the most common isotope of the element, making up about one part per trillion of the Earth's crust; essentially all natural radium is 226 Ra. [29] Thus, radium is found in tiny quantities in the uranium ore uraninite and various other uranium minerals, and in even tinier quantities in thorium minerals.
It is a mechanical pocket watch which features 57 complications, introduced by Vacheron Constantin in 2015. The company claims that it is the most complicated mechanical pocket watch ever created. The Reference 57260 took eight years to assemble, and has 2826 parts and 31 hands. It weighs 957 g (2.11 lb), and spans 98 millimetres (3.9 in).
Ingersoll was a popularizer of the use of radium on hands and indices with their "Radiolite" series, seen in this 1917 ad. In 1896 Ingersoll introduced a watch called the Yankee, setting its price at $1. This made it the cheapest watch available at the time, and the first watch to be priced at one dollar; the "dollar watch" was born.
The so-called trench watch, or 'wristlets' were practical, as they freed up one hand that would normally be used to operate a pocket watch, and became standard equipment. [187] [188] The demands of trench warfare meant that soldiers needed to protect the glass of their watches, and a guard in the form of a hinged cage was sometimes used. [188]