After a period as a naval surgeon, where he saw action with Nelson at the Battle of Copenhagen, Clanny, an Irishman by birth, settled in Monkwearmouth and remained there for the rest of his life. He became chief physician at the Sunderland Infirmary and was among the first to recognise the true nature of cholera, the fatal disease which entered Britain through Sunderland in 1831 and developed into a major national epidemic.
Clanny is now remembered for his miners' safety lamp. Though without much knowledge of chemistry, he conceived the idea of insulating a candle by enclosing it in a metal lamp with water chambers above and below, and a bellows action to force air through. This lamp was made in 1812 and tried successfully in the Harrington Mill pit, a very fiery mine, in 1815. A paper by Clanny was read before the Royal Society on 20 May 1813 'On the Means of Procuring a Steady Light in Coal Mines without the Danger of Explosion'. There are no details of his experiments, and the lamp was heavy and cumbersome: nevertheless, considerable credit is due to Clanny - which he was not slow to claim. Sir Humphrey Davy's first paper on the subject was read in November 1815 after seeing Clanny's experiments with his lamp.
Clanny later modified the lamp to bring it down to about two pounds in weight and it was used in a number of North East mines. Much later he wrote a pamphlet published in Gateshead in 1844: Priority of Invention of the Safety Lamp. A purse of gold was presented to him at the Athenaeum, Sunderland on 3 February 1848 by the Marquis of Londonderry in recognition of his inventions.