1839 - apprenticed to Gardner & Co., mathematical, optical, and philosophical instrument makers. 1850 - set up his own firm in Glasgow. 1854 - started making instruments for William Thomson (Lord Kelvin), professor of natural philosophy at Glasgow University. 1857 - in partnership with John Haddin Barr, traded as White and Barr. 1861 - applied for sequestration (bankruptcy). 1858 - credited with improving Thomson's patent for a mirror galvanometer for the Atlantic telegraph project. 1870 - equipped and set up Thomson's new laboratory at Gilmorehill. 1876 - elected a member of the Glasgow Philosophical Society.