In 1815, William Smith drew a map of the United Kingdom which transformed the scientific landscape: It laid the foundations for modern geology, and identified natural resources which would beget the Industrial Revolution. But up until last year, this first-edition copy was considered to be lost forever.
As a geologist in London in the early 1800s, Smith began looking at the alignment of fossils as a way to trace rock layers, therefore pioneering the field of stratigraphy. His work created a formal methodology for geologic surveys, influencing the way that similar surveys were undertaken in other countries. This discovery was nothing less than revolutionary, or shall I say evolutionary: Smith was highly influential in the work of Charles Darwin.
The 1815 Geological Map of England and Wales was nicknamed "The Map That Changed the World" and there's even a book by that name which asserts the importance of Smith's accomplishment -- as well as the rather sad aftermath. Because he was not a member of the intelligentsia (he was a surveyor and canal worker) he was plagiarized and lived homeless for a decade.
Smith made about 370 copies by hand throughout his lifetime, and several later maps are known to be in existence, but the earliest copies were assumed to be lost. This copy, discovered in 2014 in the Geological Society of London's own archives, is likely one of the first ten he ever produced. It has been restored and digitised, and will be preserved in perpetuity in the Society's archives, properly honouring Smith's achievement. [Geological Society of London via CityLab]