For about fifteen years (from 1893 to 1908), Lowell studied Mars extensively, making intricate drawings of the surface markings as he perceived them. Lowell published his observations in three books: 'Mars' (1895), 'Mars and Its Canals' (1906) and 'Mars As the Abode of Life' (1908). With these writings, Lowell, more than anyone else, popularised the long-held belief that these markings showed that Mars was home to intelligent life forms. Decades later, it was discovered that these channels did not in fact exist and that they were only the reflection on the lens of the astronomer's telescope of the shadows of the blood vessels of his own eyes!