When my dad went to college back in 1958, my grandma spent a small fortune to buy a 17-jewel (or was it 11?) Swiss wrist watch for him. That thing will probably be off only a couple of minutes a year. A few years back, I gave him a different watch, a solar-powered so-called atomic watch which is really a quartz watch that can synchronize to real atomic clocks through broadcast towers on three (or was it 4) continents. Adjusted for inflation, this second watch is probably cheaper. The rate of technological advancement is extraordinary over a long period of time because it's exponential. Backing off to the early part of the exponential function, you'd find glacier speeds of innovations (from today's perspective). But they are every bit as exciting and important. This book tells you the fascinating stories around the end of the 18th century when precision timekeeper was just about to be invented and chronometer was not a word yet. As they say, necessity is the mother of invention. The necessity this time was navigation -- or more specifically, longitudinal navigation.

Determining latitude at sea is relatively easily as the season changes rather slowly and thus the sun stays at stable azimuth at noon. But longitude is an entirely different thing. You need to keep time accurately. Your watch and clock do not tell current time in some magical way, they track cumulative passage of time. Therefore, any small error accumulated over a long voyage can be substantial. So much so, back then the Royal Navy essentially was rather clueless as to where they are (longitudinally) at any particular moment. Yet, uncertainty and ignorance undermine authority and are therefore not allowed to be displayed. Thus any personnel keeping his private navigation on board is capital offense! One such officer risked his life to tell his commanding officer that he thought they are in grave danger. He was hanged for mutiny. The rest of the ship drowned (with two exceptions and one of which is an admiral who despited being washed ashore alive, was later murdered for his beautiful emerald ring -- history makes stories that rival Dumas's).

That's how bad things were back then. And the great Newton himself told the parliament that it's a difficult problem and no easy path lay ahead. The parliament passed the longitude act and promised a prize ($5 million in today's currency) for the first person to tell longitude within half a degree. Then came the heroic effort of Harrison to make a series of time keepers to eventually beat the goal by a large margin. But there were so much drama and delay to his recognition. He eventually made an appeal to King George III. The much maligned king in Lin-Manuel Miranda's broadway hit "Hamilton" turns out to be a very reasonable and scientifically astute monarch. (King George, btw, is my favorite character in the musical. Now, I like him even more.) There are many interesting little stories like that throughout the compact little book. It's well worth a read.

I was reminded of this book today because in was on the PageADay Book Lover's Calendar for 3-31-2015. I read it back in the year 2000(+-). I have favorable recollections of the book, and I found it to be in interesting story. The following short review is copied from the calendar.

Anyone with an interest in history or things maritime should consider Longitude," said USA Today of this bestseller. Sobel describes 18th-century clockmaker John Harrison's struggle to invent an accurate chronometer, which measured time, necessary to calculate longitude while at sea. Requiring decades of painstaking research, Harrison finally accomplished his goal, but then faded into the mists of time until his reputation was revived by Sobel's book, which is full of little-known facts about science, ships, and England in the 1700s.
n  LONGITUDE, THE TRUE STORY OF A LONE GENIUS WHO SOLVED THE GREATEST SCIENTIFIC PROBLEM OF HIS TIME,n by Dava Sobel (1995; Walker & Company, 2007)

The link below is to an excerpt from the book:
https://t.co/NB5tdBsnKQ

The following is from the "1,000 Books to Read Before You Die" calendar for June 7, 2021.
______
It's surprising to realize that it was not until the middle of the 18th century, when Jon Harrison invented the chronometer—"a clock that would carry the true time from the home port, like an eternal flame, to any remote corner of the world"—that sailors could count on finding their way by reliable devices. Dava Sobel's Longitude tells the story of the search for this ultimate solution to one of the thorniest dilemmas in scientific history: How do you know where you are once you lose sight of land? It's an enticing, exciting chronicle of exploration, experiment, and, not least, mechanical genius.

A real gem of a book. I have spent a bit of time sitting in a sailboat dreaming of going places (instead of bobbing around the glorified bathtub we call the Chesapeake). I knew a bit about navigation but if you are starting from scratch, this is the book to read. Part science, part history, and part thriller (I may have stolen this bit from the book jacket or something, but it's true, damn it! And who are you? The plagiarism police?).

"The British Parliament, in its famed Longitude Act of 1714, set the highest bounty of all, naming a prize equal to a king’s ransom (several million dollars in today’s currency) for a “Practicable and Useful” means of determining longitude.”

I read this historical and biographical account in one evening. It's not without flaws, but I was fascinated and gave it 5 stars for holding my attention in a topic I rarely read about, where science, math, politics, and culture intersect with astronomical and nautical history. The technical details may be insufficient for some readers, but there was just enough for me. Author Dava Sobel caught my interest and held it. Kudos to her!

Anyway....Naval ships were crashing against rocks and smashing to bits, off course because finding longitude was rather a guessing game, even though latitude was fairly straightforward. Skippers didn't know how far north or south of their latitudinal orientation they had sailed. They'd run aground in the dark, the fog, etc.

So.... In 1714, King George and Parliament earmarked a HUGE reward (£20,000 pounds!) for whoever was first to come up with a highly reliable way to find longitudinal orientation.

Solving the longitude problem became a national pastime, for decades. All kinds of quacks tried all sorts of crackpot methods. Funny funny stuff!! Sensible seamen, scientists, astronomers, and mathematicians also joined the race.

However, it was a lowly clockmaker who came up with the best method. An enduring method. It became his life's work.

Did John Harrison actually win the prize, or did jealous prigs and political big-wigs cheat him of his due reward? Read it yourself to find out. It's less than 200 pages.

Sobel ranks right up there with Mark Kurlansky for writing detailed, fascinating accounts of historical technology. Calculating longitude had bedeviled mariners for centuries. To do so required an extremely accurate timepiece.

John Harrison thought he could solve the problem. The book is a nice combination of science and biography. It reminded me of another similar work Noble Obsession Charles Goodyear, Thomas Hancock, and the Race to Unlock the Greatest Industrial Secret of the Nineteenth Century which details Goodyear's lifelong attempts to discover the secrets of vulcanization.

The search for an answer was given a push when Parliament offered a huge prize for anyone who could find a way to calculate longitude accurately. A big problem was figuring out a way to overcome errors induced by humidity causing the pendulum to swell or cold making it contract. Both these effects would through off its balance inducing time-keeping errors.

I have to admit admiring the tenacity and single-mindedness with which both Goodyear and Harrison attacked innumerable problems, never giving up. It's a shame that both had to overcome non-technical personal, social, and political problems to reap any rewards for their efforts.

I bought this book recently on e-bay. It is one I have wanted for quite a while, but there is a book-buying ban in operation at my house, so I had to break cover and institute a moratorium on the ban in order to make a few semi-authorised purchases. It’s not that my wonderful wife doesn’t like books, she does, or the cost involved, although Folio Society volumes don’t come cheap; it’s more to do with the size of our house being inadequate for the number of bookcases I need to display them all. I am approaching 600 owned books, so this is a genuine challenge. Anyway, sorry to digress.

Longitude is a wonderful book, and a particularly easy read for what involves, fundamentally, science. It is the story of the search to find a reliable method to find one’s longitude at sea, something that had been perplexing some of mankind’s greatest brains for centuries. What’s the big deal? you may ask. The big deal is that if you don’t know where you are, you are likely to come a cropper (particularly, but not exclusively, in bad weather) and end up smashing your ship against rocks, islands, cliffs and other miscellaneous immoveable objects, resulting in your death. It also stands to reason that in the days when scurvy was a constant problem on board ship, causing hundreds/thousands of deaths, you needed to know when you would next arrive at a land mass or an island so that you could stock up on supplies and water. If you’re not sure whether the island you’re heading for is east or west of your current position, nor how far, you are likely to miss it, again with dire consequences. And many thousands of people did die because these things happened, as well as ships and cargoes lost at sea, and profits foregone. So the quest to find how to measure longitude accurately was a very big deal indeed.

This true story is primarily about Mr John Harrison, a country clockmaker from Lincolnshire, a rural county to this day, and the maritime clocks he spent almost his whole life inventing and developing, manufacturing them himself.

The British government had come under pressure to do something after a highly experienced and well-respected admiral of the Royal Navy had lost three ships and five hundred men in just such an accident as described above, so had put up a prize of £20,000 to the person who could solve the longitude problem. (Using one of the methods to calculate that in today’s money [purchasing power] yields a 2018 equivalent prize of £2.84m, which is about US$3.7m.)

Naturally, the prospect of becoming a millionaire and famous into the bargain stimulated many people to try to solve the problem, most failing completely and some coming up with crazy ideas, including ‘the wounded dog theory’ which was based on using ‘powder of sympathy’ (you’ll have to read the book!)

There were considered two possible methods for divining your longitude at sea:
1) The Lunar Method enabled you to navigate by the relative position of the moon to the sun (daytime) and certain fixed stars at night. This worked quite well as long as there was no or little cloud and good weather. More than one scientist (or natural philosopher, as they were called at that time) spent decades painstakingly tracking and measuring the moon’s relative position every three minutes and publishing tables from which you could calculate your distance from the place the measurements were taken from and arrive at your longitude. This method also required quite complex mathematics to work it all out, so it was not a simple solution;
2) If you knew the exact time in your home port (i.e. the port you departed from), and if you knew the exact time in your current location, you would know how long you had been sailing, and from this could calculate your longitude quite easily.

The main challenge to the second, more straightforward method, was that clocks in the 18th century were highly inaccurate, even the best available gaining or losing a minute a day. A clock or watch on a ship, however, would be even more inaccurate because it was tossed up and down on the waves and its metal components were subjected to extremes of temperature swings during a voyage – freezing cold in a European winter and broiling hot in the tropics. Expansion and contraction of the parts severely affected performance. Finding your exact time and the time elapsed since you left port was, therefore, almost impossible.

John Harrison was a highly skilled clockmaker who worked in isolation in rural Lincolnshire. He built up a local reputation as a reliable man who produced fine clocks that kept good time. He worked alone, although for a while he worked with his brother, James, and in later years he was helped by his son, also highly skilled, though not as good as the father. When he became aware of the prize on offer, Harrison decided he would produce a marine clock accurate enough to enable ships’ captains to know the time in their home port, thus providing the means for them to calculate their longitude. He invented and manufactured several new components that vastly increased the accuracy of clocks – to within a second or two a day, a tremendous improvement over what was available commercially. He built his first marine clock, known as H1, over five years.

He subsequently spent the next forty years building three more, all improved and with new components invented by him. One of these was the bi-metallic strip, a small strip comprising two metals bonded together longways – metals with different characteristics of reaction to heat and cold. If one half of the strip expanded, the other contracted, thus keeping it at a constant length. This made his clocks vastly more accurate. It is also a standard component in thermostats in all our houses and many household appliances.

Harrison had a hard time of it, mainly because the men judging the ‘competition’ were mostly astronomers wedded to the idea of the Lunar Method. Some of them also had a vested interest in using the stars to navigate by, i.e. selling the star charts and tables! Harrison was delayed, argued with, lied to and generally mucked about for decades and, unfortunately, he was his own worst enemy. Instead of hailing H1 as the solution when he demonstrated it to the Longitude Committee, he said yes, it’s good but I can do better, then went away and spent another five years inventing H2!

You’ll need to read this fascinating book for all the details, but the upshot of all this angst was that Harrison was a genius happiest when he was inventing and building his state-of-the-art clocks, which worked incredibly well. One wonders if he may have been somewhat ‘on the spectrum’, because not only was he highly focused and bright, but also very bad at expressing himself and explaining his clocks, both verbally and in writing. Either way, in the end, he got a lot of money, although not the full prize.

Ironically, the Lunar Method survived as the main way of calculating longitude at sea well into the 19th century, mainly because the accurate watches – chronometers – that Harrison invented were prohibitively expensive, making them unavailable to the majority of sea captains.

The book is very well written and Dava Sobel, who conducted extensive research to produce it, keeps you enthralled throughout. It is a fascinating story and one that needed to be told.
A solid five stars.

I learned several interesting facts in this book. Although an historical explanation of an important issue long since resolved, the author narrates the book in a very engaging manner.

I am an Arts person, not a Science person, yet I find -Longitude- Readable Science History. Enjoyable.

Full film for free
not the best quality, TBH!

An excellent piece of literary work. Smart, concise, digestable, organized and fun. A must read for all, especially scientific non-fiction lovers.

4.0 Stars - "I Really Liked It!"
Longitude - The True Story of a Lone Genius who Solved the Greatest Scientific Problem of His Time
Author: Dava Sobel - Narrator: Kate Reading

This is a review of a wonderfully fascinating book that I read in (say) April 1999 and listened to as an audiobook sometime about 24 May 2015. I thoroughly enjoyed it both times, although the technicalities of measuring Longitude were more difficult to comprehend when reading the paper book. Fortunately my somewhat dim memory assisted my comprehension as I listened to the audiobook.
Highly recommended, and a good read for the 'not-so-technically-minded' about a very technical subject.

This is the story of how a self-taught watch maker figured out how to make the first extremely accurate clock to allow sailors a reliable way to find longitude, particularly at night when it was cloudy. It's also the story of how others, mainly certain astronomers, didn't want to believe it could be anything other than a method using the sky and how some of them made it ridiculously difficult to win the money for solving this puzzle the most accurately.

There isn't much to know about John Harrison's life, but there is some, and then the author digs into some of the other people who either supported or fought against his ideas and work. This is written for the average person who knows nothing about either astronomy or clock and watch making at the time.

I am NOT going to tell you what they are, but there are two brilliant things that John Harrison was the first to figure out that are still used in devices, and at least one is something you have probably used, today.