Ada Lovelace added seven notes to her translation of Luigi Menabrea’s article about Charles Babbage’s Analytical Engine.
Written during 1842–1843, the notes were labelled A through G and were much longer than the translated article itself. Lovelace used them to explain how the proposed engine could perform repeated operations, store intermediate values, and follow a sequence of instructions.
Her notes went beyond ordinary arithmetic. She discussed how the machine might manipulate symbols representing music or language, not just numbers. The final note, Note G, presented a detailed method for calculating Bernoulli numbers and became central to Lovelace’s reputation in computing history.
A common mix-up is to count the translation and notes as separate publications or to confuse the seven notes with the article’s original sections. The notes are specifically the A–G series added by Lovelace.