The “Notes” are a series of seven annotations written by Ada Lovelace to accompany her English translation of Luigi Menabrea’s 1842 article on Charles Babbage’s Analytical Engine. Published in 1843, these notes are three times longer than the original article and contain what is widely considered to be the first computer program.
Origins
In 1840, Babbage traveled to Turin to present his Analytical Engine to Italian scientists. The mathematician Luigi Menabrea attended these lectures and subsequently published an article in French describing the machine. Ada Lovelace, who had known Babbage since 1833 and understood his work deeply, was asked to translate the article into English.
Rather than simply translating, Lovelace added extensive notes labeled A through G that expanded on Menabrea’s description and explored the theoretical implications of the machine.
Note G: The First Program
Note G contains a detailed algorithm for computing Bernoulli numbers using the Analytical Engine[1]. This is considered the first published computer program because:
- It describes a complete sequence of operations for the machine
- It includes loops and conditional branching concepts
- It specifies how variables would be stored and manipulated
- It was designed for a general-purpose programmable computer
While there is scholarly debate about Babbage’s contributions to this algorithm, historian Stephen Wolfram argues that “there’s nothing as sophisticated—or as clean—as Ada’s computation of the Bernoulli numbers”[2].
Visionary Insights
Beyond the algorithm, Lovelace’s notes contain remarkable insights that anticipated computing by a century:
Computing beyond calculation: Lovelace saw that the Engine could manipulate any symbols according to rules, not just numbers:
“The engine might compose elaborate and scientific pieces of music of any degree of complexity or extent.”[3]
Limitations of machines: She also presciently noted that the Engine could only do what it was instructed to do, anticipating debates about artificial intelligence:
“The Analytical Engine has no pretensions whatever to originate anything. It can do whatever we know how to order it to perform.”
Impact
The Notes remained relatively obscure until the 20th century, when computer pioneers rediscovered them. Today they are recognized as a foundational document in computing history:
- The Ada programming language (1980) was named in her honor
- Ada Lovelace Day celebrates women in STEM each October
- The Notes demonstrated that theoretical computer science could exist before physical computers
Sources
- Wikipedia. “Ada Lovelace.” Describes Note G and the Bernoulli numbers algorithm.
- Stephen Wolfram. “Untangling the Tale of Ada Lovelace.” Analysis of Lovelace’s contributions to the algorithm.
- Ada Lovelace, Note A. “Sketch of the Analytical Engine.” Original text of the Notes.