Long-beam oertling balance, 1896.

This balance was used by William Ramsay (1852-1916) and Maurice Travers (1872-1961) in their research into inert gases which led, in 1898, to their discovery of the existence of neon, krypton and xenon. Ludwig oertling, who designed the balance, settled in London in the early 1850s and his firm became the leading manufacturer of balances in Britain.