Meet Ada Lovelace: The Notes Were the Invention

A translation that outgrew its original

In 1843 Ada Lovelace translated an Italian engineer's paper describing Charles Babbage's proposed Analytical Engine — a mechanical computer that was never built. Babbage suggested she add her own notes. She added seven, labelled A to G, and they ran roughly three times the length of the paper she was translating.

Note G contains a step-by-step method for the machine to compute Bernoulli numbers. It is generally regarded as the first published algorithm written for a machine to execute.

The part Babbage did not see

Babbage thought of his engine as a calculator. Lovelace saw further: if the machine could manipulate symbols according to rules, and if numbers could stand for things that are not quantities — pitches, letters — then it could operate on anything expressible as symbols. She suggested it might compose music.

That is the leap. A century before there was hardware to test it, she had separated the idea of computation from the idea of arithmetic.

The caution that came with it

That line is from Note G, and it is the earliest careful statement of what a machine can and cannot do. She is not being modest on the machine's behalf; she is drawing a boundary. The engine will follow instructions with perfect obedience and originate nothing. Everything interesting has to come from whoever writes the instructions.

She died at thirty-six. The Analytical Engine was never built in her lifetime, or in Babbage's.

Why they belong at your table

Seat her when you are trying to see what a new tool is actually FOR, rather than what it was built to do. She is the first person on record to look at a calculating machine and see something else entirely.