Ada’s Algorithm by James Essinger

Reviewed by Peter Hobson

adas-algorithmOne of the most accomplished women of the nineteenth century and little known until recently outside mathematical and computer science circles, Ada Lovelace is the subject of this biography. As the daughter of Lord Byron she was inevitably eclipsed by her famous and infamous father. This book seeks to put Ada back into the limelight as she greatly deserves*.

Her early years are ruled by her wealthy mother who, however, is rather more enlightened about educating Ada than would have been typical for many such women. This reflects Lady Byron’s own broad education and she sets about zealously ensuring the same for Ada, though no possible thought of any future career as an adult other than conventional marriage was being entertained.

The key year in Ada’s story is 1833 when, in her late teens, she meets in London the other main character in this book, Charles Babbage. From this point until her early death in 1852 their lives become intertwined within the astounding mechanical mechanisms that formed the Difference and Analytical Engines. The growing need for precise and accurate tables of numbers (for example logarithms) led Babbage to seek to automate what was then a hugely time consuming manual activity of tabulation. Ada was fascinated by the concept and her extensive mathematical education enabled her to see the possibility of not only championing the concept but contributing intellectually as well. Finally, she could see an “acceptable” outlet for her talents.

Essinger describes at some length, but not in any great technical detail, Ada and Babbage’s close collaboration over the next two decades. He makes a convincing case that Ada was the one who, following her translation from the Italian of a work by the engineer Menabrae, came up with the concept of what we would now call computer programs. Ada extensively annotated her translation and it is in these notes that her genius is revealed. Lovelace speculated, correctly as we know now, that in principle the machine could go beyond numbers and manipulate other symbols in accordance with rules. She saw that numbers could represent entities such as letters of the alphabet or musical notes. Thus by manipulating numbers these machines could go beyond their original purpose of creating mathematical tables. The biography ends by describing how Ada’s life was cut short by cancer and how she lost a very large sum of money on horse racing. At the end she was once again indebted to her mother who paid off all the creditors. With Ada’s death a guiding spirit for Babbage (a difficult character who certainly needed her managerial skills) was extinguished and her contributions overlooked and little understood.

Essinger has written a very readable book about a woman who is now deservedly emerging from the shadows and whose contributions were so ground-breaking that their implications were not seen for almost another century. He makes a convincing case that even Babbage himself did not really understand what she was proposing. Interested in Victorian Britain? Interested in the early history of computing? Interested in human relationships and the challenges of breaking free from the conventions of society? Then Ada’s Algorithm is a book you should read.


Peter Hobson is a particle physicist who once owned a book on the computer language named after Ada Lovelace. He posts from time to time on his weblog Morgana’s Cat.

James Essinger, Ada’s Algorithm (Gibson Square, 2017). 978-1783340712, 254 pp., paperback.

* For more about Ada – see Peter’s Shiny review of the graphic novel – The Thrilling Adventures of Lovelace and Babbage by Sydney Padua – here.

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