This book is a historical overview of computing that traces the evolution of calculation from prehistoric tools to early mechanical devices. The text highlights how ancient artifacts like the Lebombo and Ishango bones served as the first physical records for numerical data and mathematical logic. It details the development of the abacus across various global civilisations, alongside the algorithmic foundations laid by Indian and Islamic mathematicians. 

The author also explores mechanical marvels like the Antikythera mechanism and the invention of logarithms and slide rules, which simplified complex navigation and astronomy. He details early attempts to automate thought through the clockwork calculating machines of pioneers such as Schickard and Pascal. He also covers the Industrialisation of the Calculator with de Colmar’s Arithmometer and its refinement by the likes of Burkhardt and Tate. Competitive, and ultimately better, mechanisms like Odhner’s pin-wheel mechanism and Felt's Comptometer are covered, right up to their obsolence tiriggered by the advent of electronic calculators.

Babbage's Difference Engine and Analytical Engine feature strongly as does his muse, the brilliant Ada Lovelace. The narrative covers Hollerith and the Birth of IBM and the business model that was standardised by Watson Sr. in the form of the iconic 80-column punched card. And it details how moving from decimal to digital calculation via Boole's logical framework leads almost directly to the era of vacum tube computing. 

It doesn't end there. The final chapter looks at the violent acceleration of technology forced by the necessity of World War II, reporting isolated Innovations in Berlin, Bletchley Park and Iowa, that led to programmable digital computers. It covers Turing and Flowers' code-breaking endeavors and the colossal machines that powered them. And it explains how the von Neumann architecture was born and records the advent of the commerical computer industry. These vacuum-tube giants established the pillars of the digital world — strategic data, standardised procedures and professional programmers — but they were fragile giants that were soon shrunk by the transistor and the integrated circuits it spawned, the subject of the next book.