You should also consider "Notation as a Tool of Thought" by Kenneth Iverson (his Turing Award lecture) to be required reading.
I thought I had read it at some point, but now it doesn't ring a bell. Well, it's on the list now. It starts with Babbage quote and uses phrase "tool of thought" which coincides early computer history books I've been reading.
You should also consider "Notation as a Tool of Thought" by Kenneth Iverson (his Turing Award lecture) to be required reading.