Asimov attempts to create a real-world technology chronology. This reminds me of the tech trees found in strategy games like Civilization. This encyclopedic tome is not a book you would normally read cover to cover, and I'll be honest: I'm only less than a quarter of the way through. I read from the beginning of time to 1519 (500a), just to get a feeling for the book, and really learned a lot. Some surprising things about early human history:

• Dizzying array of horse-related inventions: metal stirrups giving more stability to the rider, iron horseshoes to let horses travel further, horse collars to increase pulling capacity by 5x.
• The perfect plow, called the Moldboard or Turnplow had a vertical knife-blade that cut deep into the earth. Useful for damp, moist ground, led to increase in carrying capacity.
• Telling time, from water clocks to more accurate weight-powered mechanical clocks, to spring powered watches that could be much smaller.

But also, let me nitpick a bit. In addition to inventions, the author spends an inordinate amount of time on geographic discoveries, which feels disconnected from the rest of the narrative. Some other "discoveries" are hard to square with the rest of the content, such as "the rational interpretation of dreams", first discovered? invented? in 480 BC.

Although an attempt is made to be international, some entries are extremely Euro-centric. For example, the entry on fermentation is dated 1800 BCE, but according to Wikipedia, fermentation was actually first done in 6000 BCE in china. Many other inventions also chronicle explicitly the arrival of the technology to Europe, such as Gunpowder which is dated 1249 CE but as the entry admits, was first used to scare Chinese enemies in 1044 CE. The listed date was when the technology arrived in Europe and was perfected to make serious weaponry. My last critique is that some of the writing felt stilted and inconsistent. I imagine that Asimov worked more on the skeleton, and perhaps let a ghostwriter fill in the details.

Despite some shortcomings, Asimov's Chronology of Science and Discovery is a really impressive tome, and a reference book I'll keep close by. I've started on a summary of the chronology in spreadsheet form. Please help me by filling in the remainder of the spreadsheet for the remaining 500 years (1519 - 2019). My goal is to ultimately generate a visual, Civilization-style technology tree for this whole book.