Charles Piazzi Smyth (1819-1900), British astronomer. Smyth became the Astronomer Royal for Scotland in 1846, although his observatory was underfunded at the time. He pioneered the field of infrared astronomy by studying the Moon at infrared wavelengths. He was also the first to realise that city lights interfered with observations, and he founded the first high- altitude observatory in 1856 in the Canary Islands. The site is now occupied by the Las Palmas Observatory. Smyth also set up the One O'clock Gun in Edinburgh, Scotland, which was first fired on 7th June 1861. It indicates the time to ships in nearby Leith harbour.