A Scientist, a Fort, an Improvised Measurement

fort_prince_of_walesAt the climatology blog Watt’s Up With That, guest blogger Tim Ball has a story of how an obscure fort in remote Churchill, Manitoba on the west coast of Hudson’s Bay became the avenue for a scientific competition between France and the British Empire that shaped the world by validating Newton’s Law of Gravitation — or would have done, if the damnable instruments worked. A key player was a British scientist of unprepossessing background:

william-walesWilliam Wales (1734 – 1798), was born in Yorkshire to working class parents. He moved to London and married Mary Green, the sister of astronomer Charles Green.

He obviously showed mathematical ability because in 1765 he entered the employ of the Astronomer Royal, Sir Nevil Maskelyne. He began work on one of the two major scientific challenges of the day, the accurate determination of longitude. However, that was to become interlinked with the other challenge, testing of Newton’s Theory of Gravitation, published in 1687.

via Scientific Integrity is Constant Challenge: A Classic Historical Example | Watts Up With That?.

measuring_the_transitThere were several possible ways to do this, and the way that Sir Nevil proposed, Wales didn’t think would work. He got assigned to do it any way — he would go to Churchill, and on the other side of the world, explorer Captain James Cook would be in Tahiti, and they would observe the transit of Venus across the Sun, timing it with precision chronographs, and then by application of trigonometry, they’d have the missing ingredient to plug into Newton’s law of gravity.


Previous attempts by both European rivals had failed; the next window was 1769.

newtons_law_of_gravityThe major reason for the 1761 failure, inadequate instrumentation, was not resolved. Nobody knew this better than William Wales. In a parallel of today’s global warming fiasco, the scientists, who were effectively bureaucrats or relied on sponsorship, believed that political support and more money was the answer. So Wales faced a dilemma, keep your mouth shut and do what the King and his lackeys like Maskelyne wanted, or face incarceration and possibly even hanging.

Wales didn’t think the instruments were accurate enough.

Finally, Wales agreed to take up the challenge, but only after negotiating a generous contract that included provision for his family should he not return….

Wales knew the accurate timing was essential to success. He also knew the problems of producing an accurate chronometer. One was specially constructed, and on the Atlantic crossing, he tested it rigorously only to discover it was losing several minutes every day. It was inadequate.

They took a prefabricated observatory with them and on arrival set it up on the SE bastion of Fort Prince of Wales.

It was a working fort, and England was intermittently at war with France.

It was a working fort, and England was on a brief respite in its intermittent war with France at this time.

In the Georgian era, Wales couldn’t just send for a new chronograph from the remote wilderness of Churchill. And he couldn’t use the one the Royal Observatory had given him. He was trying to measure an angle that would turn out to be 9.57 milliradians. So what options were left?


He built a sundial. (Image at right). Archaeologists unearthed it at the Fort and it now rests in the Parks Canada museum in Churchill.

The challenge for Wales was to establish some way of determining time more accurately than with his failed chronometer. During the restoration of the Fort, a remarkable sundial was dug up at the base of the wall. They also found an iron spindle that allowed the user to turn any of 24 faces toward the Sun.

Ball and Leslie Ross were able to demonstrate that the sundial definitely was Wales’s: it contains the same exact error that is in his after-action report to Sir Nevil and the Royal Society.

In a 1984 article “Observations of the Transit of Venus at Prince of Wales’s Fort in 1769” I identified the latitude Wales had calculated for the Fort. Leslie Ross, a researcher at the National Museum of Canada, was also doing research on the sundial. He asked where I obtained the latitude. I told him it was the one Wales recorded in his journals. He said the latitude matched his calculations for the latitude of the major sundial face (June 1983 Stone sundial from Fort Prince of Wales. Research Bulletin #193). It was clear evidence that Wales made the sundial because both latitudes were different from the actual latitude by 11 minutes. I was skeptical that a sundial could be better than even a faulty chronometer, but Ross told me it could determine the time to within two minutes, which made it superior to the watch.

And the report itself says something about Wales:

On his return to England Wales … refused to submit his report. He said the results were of no value. The timing was imprecise, and the telescope optics were inadequate. Wales was finally ordered to submit a report that was published in the Philosophical Transactions of the Royal Society.

We are fortunate he complied because Wales did not waste his time but carried out countless other experiments and made many observations. He brought the first barometers and thermometers, constructed to Royal Society specifications to northern North America. He produced an excellent instrumental record beginning in 1768. This continued after he left because he instructed the surgeon in their use.

In the end, Wales’s imperfect measurement of the transit of Venus was overtaken by better measurements, validating Newton’s law. And he resumed work on his other great challenge, measuring longitude.

Far from being angry with Wales, his peers were impressed with his integrity, and when he resumed work on the longitude problem…

Two years after his return to England, the Board of Longitude commissioned him to sail as astronomer and navigator with Captain Cook. Wales job, in association with William Bayly, was to test Kendall’s K1 chronometer based on the H4 of John Harrison.

cooks-chronometersThese superior chronometers resolved many problems, and Wales is a fine representative of the many nameless scientists who toiled (and still toil) in the shadows, gradually dragging the world of the past into a better informed future. Do Read The Whole Thing™.

And what of Fort Prince of Wales? This may have been its high point. While it had 42 guns and another battery of six more across the Churchill River, its garrison was depleted and construction ceased after 1771. During a French raid in 1782, the garrison comprised only 39 civilians, and the fort was surrendered to the French with no resistance or loss of life, and its structures and goods sacked and burned. The cannons on its walls? They never fired a shot in anger. It’s now a Canadian national park and tourist attraction… for tourists willing to travel to someplace that is still quite remote.

10 thoughts on “A Scientist, a Fort, an Improvised Measurement

  1. Sabrina Chase

    The whole story of the Transit of Venus scientific expeditions is right up there with Indiana Jones, and it was indeed a big f-ing deal at the time. My favorite was the crazy Russian dude who had to get to some godforsaken quadrant of Siberia or Finland and had sleighs falling through the ice and wolves–but he made it! We modern scientists have it much easier…

    A good book on the whole thing is “Chasing Venus” by Andrea Wulf. Cool science plus war, politics, and the French being French.

  2. Bonifacio Echeverria

    It is often overlooked that the whole Venus affair, and the longitude and Newton controversy did indeed fuel a quest that did made possible a fabulous amount of knowledge of the wider world reaching Europe of the XVIII century. There was no European nation that did not have one or several expeditions sent to far away lands in those years with that scientific excuse.

    Mostly they were out to find in Newton was right or not, quite an issue back in the time, but since they were there, they took the oportunity to bring back scores of drawings and writings of geographic, geologic and etnographic information also. Many a monarch did discover what he actually owned at the return of one of these expeditions. Many a monarch, too, decided it would not be undone by his cousins and sent his own expeditions to see what did he own, and what did his peers own, in a emulation game that contributed to even wider knowledge of the world natural and human.

    Then French guy came up with the idea of compiling all that info pouring in into a single series of books…

  3. Tam

    Tangentially related, have you seen the British miniseries Longitude? If not, it’s worth a watch. Heh. “A watch”… I kill me.

    1. Hognose Post author

      It’s actually linked at the story I quoted and linked, and I was looking forward to it. But on my main computer, I have somehow been able to euthanize Flash, which gets me a mildly annoying “You must update!” alert instead of every. damned. pop-up ad. Which in NH at the moment are mostly attack ads about how awful our Senator and the woman who would replace her both are. So I’m enjoying the peace and quiet for a change. I can probably watch it here (I’m on the gunsmith bench computer this afternoon).

      1. loren

        Try ad blocker. I get nothing like that and very few adds. Some sites reject you if you have it but too few to be a worry.

  4. staghounds

    Finding the sundial is amazing, thank you!

    I believe chronometer, not chronograph, is the correct term. A chronometeis a very accurate timekeeping device, displaying time. A chronograph is a device which measures and displays elapesd time- a stopwatch, for example.

    If you haven’t read it,


    is a lively book about the interaction of society, history, and timekeeping technology.

  5. Docduracoat

    Longitude was such a great book and series!
    Harrison really suffered making an accurate chronometer
    The King of England had to intervene to give him prize money when the Admiralty refused to award him the prize he had won.

  6. Nadnerbus

    The same process of measurements would later find that the precession of Mercury’s perihelion did NOT match Newton’s predictions, a discrepancy that would not be explained until Einstein’s theory of Relativity.

    I really wish they would have covered this kind of thing when I was a kid in school. I never learned about the great adventure that is western scientific advancement until I read Sagan’s Cosmos.

  7. Claypigeonshooter

    Off topic story, my late Grandpa on my mothers side served in the U.S. military in the the late fifty’s and got stationed in Churchill Canada. If I recall right he thought it was a waste of his time because he was trained to work on heaters, but they didn’t have the heaters there that he was trained on so he was stuck working in the PX store (probably also could factor in he was recently married). He also said that the army launched rocket experiments there and that it was bitterly cold. I am grateful for his service even if he didn’t think much of it.

Comments are closed.