Interpretive map of Mars showing canals and albedo markings. Source: McLoughlin E.V., Thompson H. 1943. The Book of Knowledge: The Children’s Encyclopedia. Volume 9. p. 3291-2 Note: This series was published from the 1910s to the 1964 in the USA. This page is from the 1943 edition.  This map appeared in several editions. Based on maps […]