Which chemical element was once used (with hindsight, irresponsibly and dangerously) in luminous markings on watches, clocks and instrument dials?
Radium Biraco, a subsidiary company of Union Minière du Haut Katanga (UMHK) in its Olen plant in Belgium. The common historical unit for radioactivity, the curie, is based on the radioactivity of Ra. Radium was formerly used in self-luminous paints for watches, nuclear panels, aircraft switches, clocks, and instrument dials. A typical self-luminous watch that uses radium paint contains around 1 microgram of radium. In the mid-1920s, a lawsuit was filed against the United States Radium Corporation by five dying "Radium Girls" – dial painters who had painted radium-based luminous paint on the dials of watches and clocks. The dial painters
Duties on Clocks and Watches Act 1797 Duties on Clocks and Watches Act 1797 The Duties on Clocks and Watches Act 1797 (38 Geo. III, c. 108) was an Act of Parliament passed by the Parliament of Kingdom of Great Britain. During the last three decades of the eighteenth century, the price of watches declined and consequently they increased in popularity. William Pitt, the Prime Minister and Chancellor of the Exchequer, decided to tax watches and clocks. The Act taxed gold watches at 10 shillings and silver and other metal watches at 2s. 6d. The Act also required makers or dealers in watches and clocks to purchase