observation of the appearance of 'canals' on Mars, and indeed drew different ones ['canals' had been mistranslated from the Italian canali and was meant to mean 'channels']. His sketches of the canals, and also two sketches from John Dreyer the Danish-Irish astronomer working at Dunsink, were included on a Mercator projection map in the fourth edition of. Webb's Celestial Objects (1881). However, Burton stated very clearly that astronomers should be circumspect over the permanence of the features: 'Considering the difficulty of the objects… [interpretations] given these streaks by different observers hardly afford grounds for surprise. Great caution is necessary in asserting that any "canal" is a recent formation, considering our present almost total ignorance of the conditions.’ Definitive proof of the absence of linear features was only provided in the 1960s by the NASA/JPL Mariner 4 probe. Burton also provided the first scientific evidence of clouds on Mars, in notes from 5 January 1880, which he attributed to ground mists and the long exposure of the ice at the south pole to the Sun's energy. The Greek astronomer E. M. Antoniadi, who became known particularly for his study of Mars, referred to this historical observation as "genius". Preparations for further British expeditions to watch the next transit of Venus (1882), this time to Durban, Cape Colony, and to set up a permanent observatory, interrupted Burton's experiments at lunar photography. Weeks into this preparation, he succumbed to the heart disease at the root of his poor constitution, suffering a fatal heart-attack in the church at Castleknock, on Sunday 9 July 1882. Despite his sickly nature, some attributed his early death to repeated exposure to cold nights while observing the heavens. Legacy Colleagues of his time deplored the loss of such an outstanding astronomer at the age of 35. His colleague and friend, Wentworth Erck, wrote in the Astronomical Register: 'His loss will be deeply felt by those who knew him well, for these laud him for his blameless life and courteous manners, as much as they respected him for his high scientific attainments and unsurpassed powers as an astronomical observer'. In 1973, Burton's astronomical work was honoured by the International Astronomical Union which named a crater on Mars after him. References Further reading Chambers, P: "Life on Mars: the complete story". London, 1999. Chapman, A.: "The Victorian amateur astronomer". Chichester, 1996. Moore, P: On Mars. London, 1998 Sheehan, W.: The Planet