Title:

Caesar's Last Breath

Author:

Sam Kean

Category:

Non-fiction

Rating:

Date Reviewed:

December 25, 2025

eading an interesting book such as Sam Kean's Caesar's Last Breath makes me wish I was a science teacher. I imagine myself telling a classroom of kids some of the great stories about science that Kean's relates here - I bet some of the kids would actually look up from their phones and pay attention; I think the material in this book is that intriguing. (In reality, I would probably be a terrible teacher, but I bet that real teachers could mine this book for information that would make science class more appealing.)

Caesar's Last Breath is the story about gases - particularly the ones in our atmosphere. This leads to all sorts of discoveries and fascinating stories of quirky personalities and unexpected outcomes.

Did you know that James Watt did not invent the steam engine? There already existed a steam engine invented by Thomas Newcomen that used a steam driven piston to pump water out of tin mines in Cornwall. Unfortunately, the Newcomen engine was not very efficient, and it consumed huge quantities of coal to drain the mines. The University of Glasgow had a two-foot tall model of the Newcomen engine in its classroom that was broken, and so it hired James Watt to fix the toy. Watt made the repairs but was frustrated by the inefficiency of the engine. He decided to build a better one. After much effort and research, Watt hit upon the idea of a having a separate condensing chamber. Watt's machine worked so much better it used only a quarter of the amount of coal as the Newcomen engine - and the Industrial Revolution was born. Watt also hit upon the idea of specifying the output power of his machines in terms of horsepower. Every factory owner knew the number of horses that were required to turn their mill wheels, and so they just needed to order a ten horsepower steam engine to replace ten real horses. Steam engines meant that factories no longer needed to be located next to rivers (the currents used to turn the factory wheels) - now factories could move to cities, and urbanization increased. In 1882, physicists established a new unit to specify power, they called it the watt.

The U.S. military initially selected the Galapagos Islands for their nuclear bomb testing but then changed the location to Bikini Atoll. The details of these above-ground bomb tests are harrowing to read; there was little thought given to fallout of radioactive particles. Weapons testing performed in Nevada distributed radioactive strontium-90 and iodine-131 across the US, carried on the prevailing winds as far as Iowa.

Albert Einstein and Leo Szilard once collaborated on the best ways to make a refrigerator. Existing fridges as that time used toxic gases - ammonia, methyl chloride or sulfur dioxide - as their refrigerant. Occasionally, the seals broke on these fridges and everyone in the home would die of toxic poisoning. Einstein and Szilard's solution eliminated the compressor and the poison gases; they called their fridge Volks-Kuhlschrank - the people's fridge. However, non-toxic Freon was invented and so we still use refrigerators with compressors. Prior to refrigeration, breweries could only make beer in the winter and then store it. (Lager means "storage" in German.)

The story of Project Mogul and Area 51 alone makes this book worth reading, but other fascinating chapters talk about subjects such as the Haber-Bosch process, which invented artificial fertilizer so we could feed the billions of humans on the planet today. The reader learns about hot air balloons, the discovery of the noble gases and how neon lights work, the eruption of Mt. Saint Helen's, Nobel's invention of dynamite, the attempts to predict the weather - which lead to the origin of chaos theory and famous butterfly effect (A flap of a butterfly's wings in Brazil might result in a tornado in Texas). There was a bitter rivalry between Joseph Priestley and Antoine-Laurent Lavoisier over who deserved credit for the discovery of oxygen. There are many strange personalities, fortuitous discoveries and just amazing things that I did not know. I consider this to be best kind of non-fiction writing.

Even the endnotes of this book are worth reading. Check out this entry: The most deadly gas outburst in history took place in Iceland in 1783, when a volcanic fissure spewed poisonous gas for eight months, ultimately releasing 7 million tons of hydrochloric acid, 15 million tons of hydrofluoric acid, and 122 million tons of sulfur dioxide. Locals called the event Moduhardindin, or the "mist hardships", after the strange noxious fumes that erupted - "air bitter as seaweed and reeking of rot," one witness remembered. The mists killed 80 percent of the sheep in Iceland, plus half of the cattle and horses. Ten thousand people there also died - one-fifth of the population - mostly of starvation. When the mists wafted over to England, they mixed with water vapor to form sulfuric acid, killing twenty thousand more people. The mists also killed crops across huge swaths of Europe, inducing long-term food shortages that helped spark the French Revolution six years later.

I imagine Kean is an interesting guy to talk with - he must have a ton of material that wasn't included in this book. I see he has written some other books that I have not read yet are available in our library system. I must check them out. Caesar's Last Breath is highly recommended!