The 15th edition of the Encyclopedia Britannica, published in 1974, cost $32 million to create. The largest investment in publishing history. And yet you can now buy the complete set for pennies.

Who invented encyclopedias? Who wrote for them? And why did Samuel Taylor Coleridge get so upset about them?

Dallas is joined by Simon Garfield, author of All the Knowledge in the World: The Extraordinary History of the Encyclopaedia.