This image shows how iPad owners can examine the detail of the Codex Arundel using text, video and audio.

The British Library said over the coming months users will be able to download other titles including Alice's Adventures Underground, Lewis Carroll's handwritten and illustrated original of Alice's Adventures in Wonderland, William Blake's notebook and the Tyndale Bible, the first English language bible to appear in print.

The Codex Arundel is one of Leonardo's most famous notebooks, filled with illustrations and written in his mirror script. The notebook is one of the most important sources for understanding his work as a natural philosopher, engineer and artist, and documents scientific and technological practice in a period from which few other scientific manuscripts survive.

The British Library has also released the Mercator Atlas of Europe, created by Gerardus Mercator in the 1570s to plan the prince of Cleves' tour of the continent. Shown here is part of Mercator's map of England.