You’d be able to see far with this week’s curiosity

Last week’s curiosity was King Alfred’s cake, a fungus that grows on dead trees. According to legend, King Alfred the Great was hiding out in a countryside cottage during a war. He was told to remove the cakes from the oven, but fell asleep and burned them instead. The fungus is said to resemble a burned cake.

This week, can you identify this old piece of scientific equipment? There’s a clue in the title of this post.