Ada’s Algorithm: How Lord Byron’s Daughter Ada Lovelace Launched the Digital Age – James Essinger

Thoughts: I finished this book feeling somewhat disappointed. Guided, perhaps, by the title, I expected an explanation of the first computer program in history that Ada Lovelace was purported to have written in 1843 for Charles Babbage’s Analytical Engine. Instead, the book was a biography of Lovelace, and when the titular algorithm finally came up in the last third of the book, Essinger offered only a general description of it, doing little to explain how it worked. The book featured many, unnecessarily lengthy quotations from Lovelace’s correspondence with Babbage and others. And for all his discussion of how Lovelace’s work was discounted by Victorian society because she was a woman, I found Essinger’s convention of referring to male figures by their last name and female figures by their first rather grating.

(The notes below are not a summary of the book, but rather raw notes - whatever I thought, at the time, might be worth remembering.)

Essinger, James. 2014. Ada’s Algorithm: How Lord Byron’s Daughter Ada Lovelace Launched the Digital Age. Melville House.

• xi: To learn more about: Rosalind Franklin, who contributed much to the discovery of DNA’s double helix structure but was passed over when the Nobel Prize for the discovery was awarded.
• 62: To learn more about: Mary Somerville, friend of Lovelace and “one of the greatest mathematicians [in the world].”
• 74-76: inventions that revolutionized the textile industry:
  • John Kay’s “flying shuttle” 1733 - allowed the shuttle to be shot through a loom, speeding up weaving
  • James Hargreaves’s spinning jenny 1764 - allowed wool to be quickly spun into yarn (but it was weak yarn)
  • Richard Arkwright’s “water frame” 1771 - allowed yarn to be automatically spun that was stronger than spinning jenny yarn
  • Samuel Crompton’s “spinning mule” 1779 - spun high-quality yarn, but matched the rate of the spinning jenny
  • steam engines, especially those of James Watt
  • Joseph-Marie Jacquard’s loom 1833 - allowed complex patterns to be automatically woven into textiles
• 76-77: Jacquard’s loom used a series of punched cards to control the warp threads in a weave, allowing single weavers to work about 24 times as fast as two weavers previously could
• 82: in the mid-1800s, engineers relied on large tables of logarithms to do calculations, but these the values in these tables were worked out (and often copied) by hand, increasing the likelihood of errors in calculation. Babbage’s Difference Engine was designed to automatically generate these values.
• 90: Babbage’s designs depended on numbered cogwheels, which had several important properties
  • they were gears, so could pass energy on to other gears
  • this energy is passed around in precise, incremental steps (i.e. digitally)
• 105: while studying at Trinity College, Babbage formed a club with his friends, called The Extractors, “designed to help its members should any of them be the subject of a petition to get them sent to a lunatic asylum”
  • j: wow! this says a lot about how people with mental health issues were treated in Britain in the early 1800’s…
• 109: the practical value of logarithms in performing calculations: if you want to multiply two numbers, simply look up their logs and add them. This sum will be the log of the product of the two numbers, and can be looked up in reverse.
• 119: “The Jacquard card can even be said to constitute the invention of the binary digit or ‘bit’” - presumably, 1 and 0 corresponding to warp over and warp under woof
• 136: to learn more about: Maria Agnesi, credited as the first female mathematician - wrote a large, two-volume work on mathematics in 1748, and became a professor at the University of Bologna
• 166-167: Lovelace’s main contribution, in Essinger’s estimation, was in seeing the potential of devices such as the analytical engine - whereas Babbage looked at it as a tool for working out mathematical equations, Lovelace recognized that you could represent things in domains beyond math, and even beyond science (e.g. the composition of music) and work with them using the AE.
• 235: mentioned: The Cogwheel Brain by Doron Swade, who built working versions of the Difference Engine and the printer from the Analytical Engine: “a unique source of information about Babbage’s life and the modern realisation of Babbage’s dreams”