Did Ada Lovelace *really* write the first computer program?

Posted on April 27, 2010


After Ada Lovelace day had come and gone, I decided to do some more reading about her.  It turns out that there’s great primary literature online, including the paper for which she is famed and the autobiography of Charles Babbage. And between the two of them, there’s somewhat damning evidence that she was not, in fact, the author of the first published computer program.


Charles Babbage was a mathematician and the inventor of the analytical engine, a machine which would read programs on punch cards, much like the computers of 100 years later, and perform computations.  The machine was never built due to lack of government funding, but the principles behind it was were sound.

Ada Lovelace was also a mathematician of her day, and greatly wanted the analytical engine to be built.  A friend of Babbage, Menabrea, wrote a treatise on the analytical engine in French, explaining its mechanism.  Ada Lovelace translated the paper and told Babbage about it, whereupon he suggested that she add to it.  She did, hoping her notes would help get the engine built.

The paper is a direct translation of Menabrea’s work, but the notes at the end, A through G, are Lovelace’s.  It’s G that is of particular note.  It contains the algorithm to calculate the Bernoulli numbers.  The analytic engine was the first computer, so this is generally considered to be the first computer program, despite the fact that it was never run.  Since Ada was the author of note G, the program and the credit of being the first programmer goes to her.  You can find note G here; it’s at the very end of the page.

The Twist

Except that she may not have been the sole author of Note G.  Babbage spends about a page of his autobiography on Lovelace’s translation, in which he claims credit for the Bernoulli number algorithm.

Here is the damning passage:

“We discussed together the various illustrations that might be introduced: I suggested several, but the selection was entirely her own. So also was the algebraic working out of the different problems, except, indeed, that relating to the numbers of Bernouilli, which I had offered to do to save Lady Lovelace the trouble. This she sent back to me for an amendment, having detected a grave mistake which I had made in the process.”

(page 103 in the epub version)


There are two possible ways to preserve Ada Lovelace’s credit for the first computer program.  The first is to call Babbage a liar, and the second is to question the interpretation of the passage.

It is possible that Babbage, upon recognizing the significance of Note G, tried to casually claim credit for it in his autobiography.  Lovelace died in 1952, and the autobiography was published in 1964.  There  would have been no one to dispute his claim that he did the legwork for note G.

Secondly, some doubt can be raised as to what the phrase “algebraic working out” refers to in that passage.  How much, exactly, of Note G was worked out by Babbage as opposed to Ada?

The truth is mostly likely ascertainable by their letters.  I do not have them, so it’s hard to pass judgment. Brian Randall, in The Origin of Digital Computers makes a similar claim as I.  Joan Baum, in The Calculating Passion of Ada Lovelace, refutes this claim.  She admits that drafts of note G went back and forth between Babbage and Lovelace, but says that “it was Ada that seemed to be in command.”  It was only natural that Lovelace seem to be in command; she was the author of the notes.  But who was the first one to draw up the program?

I also mistrust Baum’s judgement, because she mentions the exact passage I quote above, while leaving out that part where Babbage claimed credit for the Bernoulli numbers work. Instead, she uses that passage only to credit Lovelace with the work.  This is the relevant quote from her book:

“In Passages, Babbage said that the selection of illustrations, or programs, for the ‘Notes’ as entirely Lady Lovelace’s, as was the algebraic working out of the different problems”

(page 83 in the Archon Books 1986)

This smacks of gross incompetence, if not dishonesty, because that is precisely not what Babbage said in Passages, which you can read yourself, as it leaves out the qualifier of “except.” Without reading the letters myself, it’s impossible to know who originated the first computer program, but since I only have second hand accounts from a woman who seems to have deliberately obscured the truth, it doesn’t look good.

Anyone want to fund a trip for me to go to England so I can read them myself? 🙂

Posted in: Ramblings