Reading Leonardo’s notebooks

An engineer thinking on paper

A drawn machine is not necessarily a machine that ran. Leonardo’s papers mix hydraulic devices, calculations, clothing and notes. They record thinking between court commissions and personal observation rather than a catalog of completed inventions.

Forster I combines Milanese water devices from around 1487–1490 with Florentine shape-and-volume work of July 1505. Volume numbering is not chronological order.

Investigating water and weights

Diagrams allowed forces and weights to be followed on paper. The notebooks include examination and rejection of perpetual-motion ideas. Drawing helped test and revise proposals, not merely display them.

Notes on proportion and Pacioli around 1495 coexist with later weights and mechanics. Mirror writing may relate to left-handed use, not necessarily secrecy. Direction and content are distinct issues.

Design, proposal and realization

Writing crossing an inner margin can reveal work done before folding. Later binding joined papers from different times, so current order is not writing order. A modern model based on a drawing likewise does not prove Leonardo built and ran it.

Before and after

1. Around 1487–1490

   Early sheets now in Forster I.

2. Around 1495–1497

   Studies of weights and other topics in Forster II.

3. July 1505

   The Florence notebook on transformation.

4. 1876

   Forster’s bequest brought the notebooks into the V&A collection.

Key terms

Mirror writing

Writing read with left and right reversed.

Leaf

An individual sheet in a bound volume.

Proposal

A design or plan proposed before realization.

What supports the account?

Check your understanding

Choose an answer to reveal the explanation. Return to the article and sources when you are unsure.