Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time

... Show More
Longitude is the dramatic human story of an epic scientific quest. The "longitude problem" was the thorniest dilemma of the eighteenth century. Lacking the ability to measure longitude, sailors throughout the great ages of exploration had been literally lost at sea.

At the heart of Dava Sobel's fascinating brief history of astronomy, navigation and horology stands the figure of John Harrison, self-taught Yorkshire clockmaker, and his forty-year obsession with building the perfect timekeeper. Battling against the establishment, Harrison stood alone in pursuit of his solution and the £20,000 reward offered by Parliament.

184 pages, Hardcover

First published October 19,1995

About the author

... Show More
Dava Sobel is an American writer of popular expositions of scientific topics. Her books include Longitude, about English clockmaker John Harrison; Galileo's Daughter, about Galileo's daughter Maria Celeste; and The Glass Universe: How the Ladies of the Harvard Observatory Took the Measure of the Stars about the Harvard Computers.

Community Reviews

Rating(3.9 / 5.0, 100 votes)
5 stars
25(25%)
4 stars
43(43%)
3 stars
32(32%)
2 stars
0(0%)
1 stars
0(0%)
100 reviews All reviews
April 25,2025
... Show More
A matter of time. The earth’s latitude was established long before the longitude, with the former fixed by nature’s physical law and relatively consistent compared to the latter, which was made complicated by a shifting time factor. Without benefit of the longitude, thousands of seafarers in the past had risked their lives on luck and the captain’s judgement to sail the high seas. After almost four centuries of questing for a viable solution, the maritime community finally endorsed the first reliable chronometer from an erstwhile unknown English clockmaker by the name of John Harrison.

Still, due recognition for Harrison was a long time coming. Until 1773, both inventor and inventions - the four iterations were designated H1, H2, H3, and H4 - were met with disdainful opposition from the scientific elite, largely astronomers, who posited the celestial clock, not the mechanical one, as a true gauge of longitude. Harrison’s ingenuity suffered decades of academic skepticism, award sabotage, back-biting, formidable competition, financial challenges and Harrison’s own sense of perfectionism, as recounted in Dava Sobel’s Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of his Time. At times vivid and inspiring, Sobel’s telling breathed much-needed color into an otherwise dry historical event and Harrison’s even dryer personality.

Longitude barely qualified as a biography, as Harrison’s personal life was little known. He seemed to be an extraordinarily reserved person, who had taught himself clock-making without the benefit of apprenticeship or a formal education. In the eyes of most readers, the very mystery of the genius Harrison made him an intriguing historical figure. Most definitely in the eyes of this reader, Harrison’s remarkable achievements made me cheer for an underdog who succeeded against all odds to develop an accurate sea clock for measuring longitude, which also initiated a boom industry in marine timekeeping.

Longitude has enough facts loaded on for those needing details, but dramatized enough to pique my interest. It is the kind of book one might buy from the gift store after a visit to the maritime museum, or for someone into horology. Neither applied to me; the subject, book length (< 200 pages, Kindle) and my mood merely converged favorably. Someday, I hope to see Harrison’s original marine chronometers on display at the Royal Observatory at Greenwich, London. The images here will serve as reference for the time being.
April 25,2025
... Show More
This little book tells the story of how inventors attempted to solve the vexing problem of obtaining a critical part in calculating longitude -- having a reliable timepiece providing accurate, standardized time on the sea. It's a surprisingly exciting tale: there was a contest, a rich reward and a deadline for entries. Before this problem was solved, sailors could calculate latitude by the stars but longitude required consistent, reliable timekeeping in all ocean conditions from one fixed point.

Even with no penchant for science, I found this fascinating, esp. after visiting Greenwich, England, the museum and the very spot to which world time is related (as in Greenwich Mean Time). The author explains all the challenges involved and has written a suspenseful, interesting book about a subject I took for granted.
April 25,2025
... Show More
Quick, focused history books are underrated, especially when they're as well-written as this one. The subtitle of "The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time" sounds hyperbolic, but it's basically true. Sobel's account of how unknown English clockmaker John Harrison solved the longitude problem - how can sailors tell their position at sea in a quick, accurate, and reliable way in order to avoid sinking or mistaking Caribbean islands for India? - takes an underappreciated scientific issue and explains why it's important, why it was so difficult to solve, who the key players were, and why it matters today. While she doesn't wander down every single potential historical avenue or wring all of the scientific/military/political contextual details out, she's able to give the reader plenty of background for further digging, in case you want more details on the vagaries of star-sighting or constructing astronomical tables, the rivalry between Britain and France, or why exactly Nevil Maskelyne was such a jerk to his fellow astronomers and scientists.

Plus as a bonus it gives you more to ponder on how best to systematically promote scientific research: the debate over the prize system vs investing more in public universities vs offering R&D tax credits to private companies can seem arcane, but the specific example of a life-and-death situation like the longitude problem makes the tradeoffs of each unusually clear. Scientific research offers a great window into society's priorities, and Sobel's book is an excellent look at an often-overlooked example of progress at its most unexpected. Few of us mostly land-locked folks will ever need to determine the nearest meridian line from a ship at sea in a storm, but it's always worth remembering how we've benefitted from humble experimenters like Harrison, and thinking of ways to encourage his spiritual successors.
April 25,2025
... Show More
This little book is a gem. Less than 200 pages but a fascinating story. It is almost unfathomable in this age when it seems that practically everyone has a GPS device in their car, an iPhone, and a personal computer that there was a time when if you set sail you depended on luck or the grace of God to arrive at your destination once you were out of sight of land. All the explorers of the age, Babloa; Magellan; Drake, "all got where they were going willy-nilly".

In the 18th century "the wealth of nations floated upon the oceans". No ship had a reliable means of establishing her precise location. As a result an unknown number of ships and sailors were lost. It became a great quest to discover a solution to the longitude problem. It would be on par to trying to discover the cure for cancer today. Nations offered huge purses for a solution. Notable among these was the British Parliament's Longitude Act of 1714 naming a prize of several million dollars in today's currency.

Such prizes brought out the crackpots but there were basically two different legitimate schools of thought towards a solution. On the one side were the astronomers. On the other side were the horologists. The clockmakers. Among the later was John Harrison. Harrison had no formal education or apprenticeship. There is a story that as a child he came down with smallpox and was given a watch to amuse himself while recovering. There is some dispute on this as at that time a watch was both rare and expensive. None the less Harrison became a self taught clockmaker. He was a craftsman and an innovator.

Harrison's efforts in solving the longitude problem gave us the chronometer. He built four different clocks in his quest to solve the longitude problem all the while some of the worlds leading astronomers, including Edmund Halley, were mapping the stars in their effort to solve the problem. I am not sure how many people know about this chapter in our history. It is a story of navigation, astronomy, and clockmaking.

April 25,2025
... Show More
La Historia está llena de pequeños descubrimientos capaces de cambiar el mundo. Aunque debería decir pequeños vistos desde nuestros días. Este es el caso de la longitud, es decir, esas líneas imaginarias que trazan nuestro planeta desde los polos, dividiéndolo en veinticuatro partes iguales. La longitud era fundamental en tierra firme para trazar mapas lo más exactos posibles, pero sobre todo era esencial para la navegación. El mundo era un gran desconocido cuyos horizontes estaban todavía por descubrir y el único medio para hacerlo era en barco, surcando esos océanos y mares ignotos donde cualquier error de cálculo podía suponer perderse en su inmensidad y morir con seguridad, ya sea por la escasez de agua potable y alimentos como por escorbuto. Un barco podía pensar que estaba arribando a su destino cuando quizás era todo lo contrario, o podía colisionar con elementos desconocidos provocando su hundimiento.

Hay que pensar en la longitud como un elemento asociado al tiempo. Si tenemos en cuenta que circunvalar la Tierra supone 360º, que se dividen en 24 meridianos de longitud, obtenemos una separación entre ellos de 15º, calculándose cada grado en minutos. Por lo tanto es fundamental saber en todo momento el tiempo real tanto en el barco como en el lugar desde el que se ha partido o el de destino. Parece simple, con un simple reloj arreglado. Pero no es tan fácil como parece, porque la temperatura y la presión atmosférica afectan mucho la maquinaria de los relojes, adelantándolos o retrasándolos o simplemente parándolos. El capitán pensaba que estaba a X minutos de su destino y se encontraba con que el tiempo pasaba y no arribaban a lugar alguno. Y aquí entraban en juego los partidarios de los relojes y los que preferían guiarse por el mapa estelar, mirando el cielo.

Era tan importante para los países encontrar una solución al problema de la longitud, que les hacía perder barcos, mercancías, hombres y dinero, que decidieron poner una recompensa a aquél que diese una solución lo más exacta posible. El gobierno inglés llegó a ofrecer 20.000 libras, el equivalente a varios millones en la actualidad, estableciéndose así el Decreto de la Longitud de 1714.

Muchos científicos de renombre hicieron frente al reto pero sólo uno lo consiguió, John Harrison. Esta es su historia, la de él y la de otros tantos que quisieron encontrar una solución al problema. Galileo, Newton, Huygens y un largo etcétera no fueron capaces que dar con la clave. Tuvo que llegar Harrison, un desconocido, un autodidacta aficionado a los relojes, carpintero de profesión para poner fin al problema. Y no lo tuvo nada fácil, porque además de intentar construir sus máquinas de precisión, tuvo que hacer frente a la oposición de los astrónomos, empeñados en que su método era el mejor y más adecuado.

Dava Sobel, periodista científica, nos ofrece un relato claro y apasionante de un descubrimiento que cambió nuestra Historia para siempre. Parece mentira que algo para lo que actualmente son necesarios dos simples relojes de pulsera, trajese de cabeza a medio mundo.
April 25,2025
... Show More
Until reading this book, I did not know that a problem existed determining where a ship was situated longitudinally. If the sky was clear, the 'clock of the heavens' helped determine the position. If the sky was overcast, an accurate clock was needed on board. For the longest time, no accurate clock existed.

From the book:
"To learn one’s longitude at sea, one needs to know what time it is aboard ship and also the time at the home port or another place of known longitude—at that very same moment. The two clock times enable the navigator to convert the hour difference into a geographical separation. Since the Earth takes twenty-four hours to complete one full revolution of three hundred sixty degrees, one hour marks one twenty-fourth of a spin, or fifteen degrees. And so each hour’s time difference between the ship and the starting point marks a progress of fifteen degrees of longitude to the east or west. Every day at sea, when the navigator resets his ship’s clock to local noon when the sun reaches its highest point in the sky, and then consults the home-port clock, every hour’s discrepancy between them translates into another fifteen degrees of longitude."

This is the story of John Harrison who spent forty years of his life inventing a clock that could keep accurate time.

There are 15 chapters in the book, aptly named to describe the 'steps' along the way.

Exceedingly readable, this book describes the solution to the thorniest problem of its day- the longitude problem.

5 stars
April 25,2025
... Show More
Longitude is by definition a smaller story than Sobel's equally enjoyable Planets, but contains the same in-depth research, beautiful writing, fascinating historical incidents, memorable (and generally obscure) characters, and incidental humor that made Planets such a pleasure.

While focused on the amazing career of John Harrison, Sobel also introduces a solid cast of supporting characters, all of whom are worthy of having their own stories told; and while I thoroughly enjoyed the tale of Sir Cloudesley Shovell for the way his career so quickly and totally crashed and burned - well, crashed and drowned would be more like it - the true second star of this book was Commander Rupert Gould, who suddenly pops up in the last chapter a full century after Harrison's death to almost single-handedly rescue Harrison and his devices from total obscurity.

My sole complaint is that the book would have really benefited from illustrations - but excellent pictures of all of Harrison's chronometers can be found on Google images, as well as a dorky-cool photo of Galileo's bizarre celatone.

UPDATE, 01/2019: A-ha! So it turns out that there is indeed a sister version of Longitude that does have pictures: The Illustrated Longitude (https://www.goodreads.com/book/show/1...) which, in her introduction, Sobel explains was the result of so many readers commenting (i.e., complaining) about the lack of maps, photos, drawings and any other illustrations which would have earned her original book that elusive 5th star.

And not ONLY that, but turns out there's also a 2000 BBC/A&E miniseries version starring Jeremy Irons and Micheal Gambon, (aka Batman's Alfred and Prof. Dumbledore, although apparently both known for a few other roles as well)! How did I not know that??

ANYWAY...have just found both these items in our local library (the book "Donated By a Patron"); and so while I'm not going to reread the whole book, I'll definitely spend a couple of evenings watching the movie and looking at pictures and just generally revisiting this fascinating and oh-so-well-told story. So thanks, Dava Sobel, William Andrewes (provider of illustrations and captions) , BBC, A&E - and of course you too, generous Loudoun County Library Patron!
April 25,2025
... Show More
The book really made me empathise with the woes that John Harrison was going through in his dealings with the Board of Longitude, especially with Nevil Maskelyne. The history of time keeping in sea as well as the history of the time keeper in land does give a different picture of the 17th and 18th centuries in stark contrast with the 21st century. Yet how far science and technology have took us forward today really made me to contemplate upon the words Newton had once said "If I have seen further it is by standing on the shoulders of gaints". This literally stands true here, as if it was not for the dedicated efforts by men like Harrison & his son, George Graham, Kendell, Mudge, Arnold and a lot of others the world may never have seen such wonderful new instruments. 'Chronometer' earlier had ringed in me the memory of an instrument used in ships but now it truly makes me remember a bygone age where the quest for finding the longitude was the passion that kept a generation of men so avid and awake.
Leave a Review
You must be logged in to rate and post a review. Register an account to get started.