According to the experts this is the oldest European impression of Mt. Everest; it was drawn by Sir Joseph Hooker (formerly Director of Kew Gardens) in around 1848. Walter Hood-Fitch painted a version of the sketch in around1850; this was also found by the Royal Botanical Society.
This really is an incredible find; it highlights how people's interest in the Himalayas and the tallest mountain on Earth have gone on for so long and still do to this day. To find out more please visit the Kew Gardens website. It's currently on display at Kew so I'll be sure to go and check it out next time i'm around at home!