The Mystery of Champlain’s Astrolabe

This article appeared in The Beaver 84, no. 6 (Dec. 2004/Jan. 2005)

The astrolabe was discovered in 1867 near Cobden, Ontario. The idea that this essential navigation device once belonged to the most celebrated cartographer and explorer of early Canadian history has been irresistible to many. Despite academic misgivings about the Champlain provenance, in 1989 the federal Department of Communications agreed to pay the astrolabe’s owner, the New York Historical Society, a whopping U.S. $250,000 so that the astrolabe (which without the Champlain provenance would have commanded $50,000 to $100,000) could become a key part of the collection of the new Canadian Museum of Civilization in Hull, Quebec.

The Champlain provenance case for the “Cobden astrolabe” (as it is known to those squeamish about the Champlain attribution) appears so weak as to be ephemeral, and is itself an intriguing historical artifact. Long overdue in receiving full consideration is the more likely case: that the instrument belonged to a missionary of the Society of Jesus – the Jesuits, the Black Robes of our turbulent seventeenth-century history.

• • •

So what’s the case for Champlain’s ownership? Champlain made his first trip up the Ottawa River in June 1613. He was travelling with an eternally controversial figure named Nicholas de Vignau, who had wintered over among the Algonquin people on the Upper Ottawa. After returning to France, Vignau had convinced Champlain that he had visited the “Northern Sea,” what we now call Hudson Bay and James Bay, only recently explored by Henry Hudson for England. Now Champlain was on his way up the Ottawa, hoping to visit this northern sea himself.

The astrolabe, which is a genuine early-seventeenth-century device (although there is debate about how much of it has been replaced or repaired over the years), turned up in the vicinity of the portage past the Calumet rapids, about two hundred metres down Buttermilk Creek from the shore of Green Lake, since renamed Astrolabe Lake, which is a glorified pond about five hundred metres long. It was found by fourteen-year-old Edward Lee while he was helping his father, a local farmer, clear a lot for its new owner, Charles Overman, the captain of a local steamboat.

Young Lee found the object (while dad was eating lunch) when the top section of a fallen pine tree he was pulling with a team of oxen scraped clear the concealing moss and muck of the creek’s bank. No one present that day apparently gave any thought to Champlain, who was hardly a giant of history then. But his stock was on the rise. Francis Parkman had just given his career its first decent English-language overview in Pioneers of France in the New World, published in 1865. Still, there was no English translation available of Champlain’s Voyages, and the first edition to be published in Quebec, in their original French, was three years away.

Charles Overman showed up at the work site and offered the boy ten dollars – about $170 in today’s money – for what people seemed to think was some kind of compass. Edward’s dad handed it over. The boy never did see the money. The astrolabe was soon passed along to Overman’s employer, the Ottawa freight forwarder Richard Cassels, who moved to Toronto some time in the 1870s, taking the astrolabe with him.

Mariner’s astrolabes are very rare. One of the most common scientific instruments of the seventeenth century, once they became obsolete around 1700, most were inevitably melted down. Only twenty-one were known in 1966. Now we have more than eighty, mainly because of the work of marine archaeologists on shipwrecks. To understand how the Cobden astrolabe ended up in Champlain’s figurative possession around 1879, and why we should ask him to drop it like a hot potato, you first have to understand what mariner’s astrolabes were for, and how Champlain in particular would have used one.

Scientific navigation was in its infancy in Champlain’s time. To fix one’s position on the surface of the earth, you need two crosshairs: latitude, which runs east-west, and longitude, which runs north-south. Champlain could figure out latitude most readily by measuring the altitude of either the pole star or (which seemed to be his habit) the noonday sun; a “noon sight” required him to then consult a celestial almanac that gave an altitude correction (declination) for each day in order to arrive at the latitude. Figuring out an accurate longitude essentially was beyond the capacity of a trailblazing seventeenth-century explorer on the move. So Champlain’s Voyages (which for the purposes of this article will refer to all of Champlain’s published works) for the most part only offer latitude figures. (He probably recorded more in his notebook, which has disappeared). Four are from the 1613 wild goose chase up and down the Ottawa with the goose named Vignau. (1) [Note: I wrote about this 1613 journey in God’s Mercies.]

Conrad Heidenreich, a retired professor of geography at York University and a leading expert on Champlain’s cartography (who is currently editing a new translation of the Voyages for the Champlain Society), has called Champlain’s latitude results “excellent.” Professor Heidenreich has shown that the explorer’s mean error margin for the sixty-two latitude sightings in the Voyages was around 15 minutes, or a quarter degree; many errors were down in the single-digit range of minutes, and his average error for almost forty readings before something went awry on the 1613 journey was less than 13 minutes. That would get you fired as a road surveyor today, but it was pretty good, even exceptionally so, for a guy often travelling by canoe, off the edge of the known world, four centuries ago. And Champlain needs to be cut further slack, because the declination corrections in celestial almanacs often were themselves in error.

But Champlain never identified the specific instrument he used. A mariner’s astrolabe is typically a cast brass wheel with at least part of its circumference marked out in degrees and a sighting pointer (alidade) on a central pivot. Champlain most likely did have such an astrolabe on his inland journeys. And he mentioned an astrolabe in his will. But there is a big problem with the Cobden astrolabe. It’s totally unsuited to the job of precision land-based navigation and cartography.

There’s been much debate over whether or not the Cobden astrolabe could have produced the fine results that Champlain published, and this does seem fairly doubtful. But the overriding issue, which has not really been engaged, is why Champlain would have tried to produce his results with the Cobden discovery. Wondering if Champlain employed the Cobden astrolabe on the Upper Ottawa is like wondering if Mike Weir could drain a twenty-foot putt with a sand wedge during the Master’s. It might be doable with an awful lot of practice and some luck, but why on earth would Weir not just use a putter?

The compact size of the Cobden device (14.7 centimetres, versus most surviving models, which fall between 16 and 18 centimetres) suggests Champlain could have chosen it for portability, but this would have come at great expense of practicality. And its size is telling as to its designed purpose. So is the positioning of its two pinnules, the squareshaped sighting vanes on the alidade, which are only separated by about half the instrument’s diameter. The mariner’s astrolabe design rule of thumb was that it needed to be smaller and its pinnules positioned more closely together if it was to be managed on the deck of a heaving ship, particular in rough weather. What the instrument lost in accuracy it gained in basic functionality. A navigator in this situation only cared that he could reasonably determine his degree of latitude so that he could maintain a general east-west course on an ocean crossing. (2)

If more precise results were required, such as for cartography, noticeable design changes occurred. The overall diameter increased, usually to thirty centimetres or more, and sometimes the pinnules were also moved closer to the ends of the alidade – in one surviving example, right to the ends. Sightings were more accurate, but much fussier. Such devices could be reliably used if the ship was in calm water, or if the user was on solid ground. Navigators often owned more than one kind of astrolabe to suit the job at hand.

The Cobden astrolabe was plainly something a navigator would reach for on an ocean crossing, on a rolling deck, to get a very basic latitude fix. It would not have been chosen by someone like Champlain, travelling in-country, who wanted to produce latitude fixes suitable for cartography. Whatever he was using gave him the confidence to measure fractional degrees, and to do so with consistently small error margins.(3) The Cobden example’s small circumference is marked only in full degrees, with each degree about one millimetre apart. Professor Heidenreich has written that Champlain might have at best guessed at half degrees (thirty minutes) with it. He is skeptical of any assertion that one could determine smaller fractional degrees with it, out of doors, with the light of the noon sun. (4)

And even for bad-weather shipboard use, the Cobden astrolabe was an archaic design by 1613, being one of the last known examples of a wedge shape. This feature may have served to counterbalance the off-centre weight of the alidade and keep the device properly aligned vertically when suspended from its ring. By the late sixteenth century, error problems with the design already had led to more robust astrolabes with parallel sides.

I think the sheer inappropriateness of the Cobden astrolabe as the tool of a prominent, land-based, map-making explorer rules out Champlain’s 1613 journey as its source. Professor Heidenreich has proposed that Champlain was using something thirty to sixty centimetres in diameter (one to two feet), as other explorers are known to have employed. And Dr. Randall Brooks, curator of Physical Science and Space at the Canada Science and Technology Museum, has indicated the Cobden astrolabe’s inherent scale flaws would cause it to be in error by 50 minutes in the latitudes in which Champlain used it.

But we can’t dismiss altogether a Champlain attribution for this astrolabe without confronting the long-standing puzzle of how the Voyages’ latitude figures for the 1613 trip went from being extremely good to pretty awful in a matter of days. Because it’s this puzzle that led to the Champlain attribution in the first place.

• • •

A flesh-and-blood Champlain may not have dropped the Cobden astrolabe, but a historic Champlain, a creature of modern imagination, deftly picked it up. Timing was everything. We were just getting to know Champlain when an astrolabe turned up that needed an owner.

The harmonic convergence of the astrolabe with the rising star of Champlain began, innocently enough, with the 1870 publication of Champlain’s Voyages in Quebec (Oeuvres de Champlain). In the annotations by Abbé Charles-Honoré Laverdière of Laval University, a problem with one of Champlain’s reported latitude positions was noted. Champlain’s latitude figure for the south end of Lac St-Louis at the beginning of  the trip was tack sharp, off by just two minutes, and he was only in error by 12 minutes at present-day Ottawa’s Chaudière Falls. And so Abbé Laverdière couldn’t help but notice that Champlain’s latitude for Morrison Island above the Calumet Rapids portage, where Champlain’s northerly progress ended at an Algonquin village, was more than a full degree in error to the north – reported at 47 degrees, it was actually 45 degrees, 48 minutes. It was a clanging mistake, totally out of character for Champlain. Laverdière could only suggest a poor instrument as having been the cause.

Champlain became a more familiar historical figure as the 1870s drew to a close. Laverdière’s biography, originally contained within the Oeuvres de Champlain of 1870, was published separately (and posthumously) in 1877. And the Prince Society of Boston issued the initial volume in the first English translation of Champlain’s Voyages in 1878 (although the 1613 journey wouldn’t appear in translation until the final volume, in 1882). The zeitgeist knitted together Laverdière’s perplexity over the rotten latitude position for Morrison Island with the astrolabe that had passed into Richard Cassels’ possession.

The medium of convergence was Alexander Jamieson Russell, author of The Red River Country, which was published by Montreal’s G.E. Desbarats in 1870, the same year that Desbarats brought out the Oeuvres. Russell’s pamphlet On Champlain’s Astrolabe of 1879, also published by Desbarats, argued that Champlain’s latitude for Morrison Island was so bad because he had to estimate it, and he had to estimate it because he had lost his astrolabe at Green Lake.

Champlain, however, in addition to not saying anything in his Voyages about losing an astrolabe, doesn’t provide irrefutable narrative evidence for having been near the discovery site. Champlain’s portage route still hasn’t been fully analyzed – by giving the Voyages a close reading and actually inspecting the portage terrain – and has been plagued by erroneous assumptions.

The latitude problem also turned out to be more complicated than Laverdière at first thought. Champlain’s latitude for the spot where he began the portage (which is generally thought to have been at the nineteenth-century steamboat wharf, Gould’s Landing, near the present-day hydroelectric dams at Portage du Fort) was also in error by more than a full degree to the north. Explaining both uncharacteristic errors, by having Champlain lose an astrolabe between the two mistakes, took some intellectual gymnastics. There are more permutations to the pro-Champlain case for the astrolabe than I can address in this space, but I’ll boil it down to the critical ones.

Scientific analysis has indicated that the astrolabe is at least contemporary with Champlain, and a stamped date of 1603 coincides with Champlain’s joining the explorations in North America for France. But nothing is really proved by those bare facts with respect to the find near Cobden (and Professor Marcel Trudel, an authority on Champlain who produced a thin biography in 1956, saw no evidence to link the device to the explorer). Nevertheless, Russell’s basic Champlain provenance case, amplified in an influential address to the Canadian Institute in Toronto in 1879 by Toronto historian Henry Scadding, went like this:

Champlain was too good a navigator to make two horrendous latitude mistakes in a row. The odds against him getting the second sighting, at Morrison Island, as wrong as the first one, at Gould’s Landing, were, so to speak, astronomically high. So the first error, at Gould’s Landing, was the real error. Then Champlain went and lost the astrolabe near Green Lake – dropped it somehow, probably while climbing over and under a tangle of fallen pines that he mentions in the Voyages narrative. Too proud to admit in the Voyages that he lost something so essential (because not having the astrolabe might cast aspersions on his ensuing cartography), he simply used dead reckoning – the process of determining your position by estimating distance covered in association with direction – to guesstimate the latitude for Morrison Island. Thus, his great navigating skills caused him to repeat the large error margin from Gould’s Landing in the guesstimate for Morrison Island.

Scadding’s opinion, which was published in a pamphlet in 1880, was particularly influential, as he had written extensively on various historical subjects and had just finished a ten-year stint as editor of the Canadian Journal of Science, Literature, and History. The American historian O.H. Marshall repeated the provenance argument in 1880, and John Charles Dent discussed it in the Champlain biography he included in The Canadian Portrait Gallery published the same year. When the Prince Society produced the third volume of its Voyages translation in 1882, a lengthy footnote discussed the astrolabe issue and directed readers to Russell, Scadding, and Marshall. The Champlain provenance for the Cobden astrolabe was now enshrined in the only English translation of the Voyages.

Richard Cassels died in 1895 and willed the astrolabe to his son William, who promptly began trying to unload it for $1,000. In 1901, the purported connection with Champlain convinced Samuel Verplanck Hoffman, a wealthy New Jersey antiquarian who was assembling one of the world’s leading astrolabe collections, to respond to a knockdown sale by Cassels, and he paid $500 for it.

Hoffman was about to become president of the New York Historical Society in 1903, and once Edward Lee’s strange find was in his esteemed collection, it became known as the Champlain Astrolabe.(5) When the tercentenary celebrations of Champlain’s exploits kicked into high gear on both sides of the border, Hoffman was involved in them, and the astrolabe’s Champlain provenance was solidified. When the city of Ottawa unveiled in 1915 the statue of Champlain that stands today at Nepean Point, the sculptor had made sure to place the astrolabe in Champlain’s hand – albeit, upside down.

Hoffman died in 1942, leaving the astrolabe to the NYHS. After several exhibition loans to various Canadian institutions, the astrolabe was purchased for the Museum of  Civilization, despite scholarly concerns that the Champlain provenance was, at best, iffy. And the museum, to its credit, has not clung to the attribution.(6) What’s now most intriguing about the Cobden astrolabe is how poorly received an attribution far more credible than Champlain has been. This object has been crying out for a Jesuit provenance since the very day of its discovery.

• • •

Popular literature likes to relate how Champlain probably or definitely dropped the astrolabe while struggling through the downed pine trees he describes on the 1613 journey’s portage. I’ve visited the portage route and the discovery site, which is now wedged between a trailer park and a golf-course fairway, and such a tangle of fallen pines could have existed in Champlain’s time along the section of Buttermilk Creek where the device was found. (Removing a fallen pine, after all, led to its discovery.) And it’s possible to imagine this smallish cast-brass object, which weighs only 629 grams, slipping out of a pocket or pack and falling silently to the creek bank, without anyone in Champlain’s small party noticing. What’s harder to imagine is how Champlain might have dropped unnoticed the rest of the stuff found with the astrolabe, and what he even would have been doing with it in the first place.

This other stuff has been dropped by the wayside as surely as Champlain allegedly dropped the celebrated object. These items were first noted by Henry Scadding in his 1879 lecture, but he made no attempt to explain them. Scadding had personally examined and photographed the astrolabe and interviewed its owner. Richard Cassels revealed that, after receiving the astrolabe, he learned that other items had been found, “along with, or in close proximity” to it. There were two small silver cups featuring some kind of “device, perhaps a crest,” and several copper vessels that sound like small pans or trays, nested inside one another. Cassels tracked down the Lee family, only to discover that the copper vessels, which were in poor shape, had been committed to the farm’s collection of miscellaneous metal scrap: a piece was even used to patch a hole in a canoe. And tragically, the silver cups had been sold to a peddler, who had them melted down for their metal value.

The presence of the small silver cups was repeated by Dent in 1880, but they and the other items were then essentially forgotten. Edward Lee was interviewed in October 1918 by Charles MacNamara for an article published the following year in The Canadian Field-Naturalist magazine. Lee, then sixty-five, took MacNamara back to the site and described the discovery convincingly. But he declined to mention (or MacNamara declined to report) anything about the silver cups and copper vessels. Lee did surrender new information: that a rusty pile of chain had been beside the astrolabe, which he had disregarded, and which probably held a weight that hung from the bottom of the astrolabe. The astrolabe once had a ring on the bottom to which such a weighted chain would have attached, but it was broken off and lost when a clumsy Canadian museum official dropped the device in the late nineteenth century.

Now we had Champlain dropping a length of chain and possibly a weight as well the astrolabe, which we’ll return to. And as for the cups, who in the Canadian wilderness in the seventeenth century had more use for what sound very much like communion cups than a Jesuit priest? The “crest” or “device” could well have been the insignia of the Society of Jesus. Most impressive about Scadding’s failure to tweak to the possible significance of the cups is that he was a doctor of divinity, an ordained Anglican priest, and had served as rector of Toronto’s Church of the Holy Trinity from 1847 to 1875!

It’s hard to imagine what Champlain would have been doing with these cups, never mind an obsolete astrolabe that was of rudimentary use on a lumpy ocean crossing. The cups make no sense as gifts for natives, and Champlain’s party was travelling so light on the portage in a sprint for Morrison Island that they didn’t even bother bringing food. Besides, once you accept that there was actually a set of lost items, you have a package of some kind, a case or a trunk, which would have long rotted away by 1867. That doesn’t fall unnoticed out of your pocket while climbing through fallen pine trees. And the fact that these objects managed to go unnoticed for more than two centuries suggests that Green Lake and Buttermilk Creek were never on the main path of this portage.

A skeptical N.T. Gridgeman at last resurrected the long-forgotten silver cups in a 1977 Canadian Geographic article, and he made the logical link with Jesuits. These items, he wrote, “could not have been there by happenstance and, in fact, they support those authorities who say that the astrolabe in question is most likely to have been lost (or cached) by missionaries en route to or from Huronia in later years.” We can well imagine them having been cached there, perhaps at the shore of the lake, and then forgotten, only to be nudged into the creek by spring runoff and melting ice pans drifting off the lake where the creek drains through the beach. But the Jesuit attribution keeps butting its head against persistent blind spots of provenance.(7)

Alan Stimson’s authoritative survey The Mariner’s Astrolabe, published in 1988, acknowledged a possible Jesuit provenance for the Cobden astrolabe, based on Gridgeman’s assertion. But then, Dr. Randall Brooks, in his paper published on the astrolabe’s provenance in Cartographica in 1999, presented arguments against a Jesuit attribution, stating, “the missionaries were not there to chart the land, and, moreover, the Jesuit Relations, which provide details of their activities in New France beginning about 1610, make no mention of an astrolabe either being in use or having been lost by members of the order.”

  However, while missionaries “were not there to chart the land,” Jesuits nevertheless did so. As Heidenreich has noted, in the period 1634–73, all the maps produced of the Great Lakes “were either based on information compiled by members of the Society of Jesus, or were drafted by members of the order.”(8) The best of them (which are worlds beyond Champlain’s efforts in the Great Lakes), show latitude and longitude.

Then there’s the problem of the Relations not having mentioned an astrolabe “being in use or having been lost” by the Jesuits. The Relations were not a daily diary of events or a line-item audit of possessions. They were annual letters to the faithful and the order’s supporters. And one can’t have things both ways: arguing that Champlain lost an astrolabe that he never said he lost, and saying the Jesuits couldn’t have lost it because they never said they did. (Dr. Brooks, however, cautioned in his 1999 paper that “it is not at all clear that the association with Champlain is fully justified,” and he also told me that the presence of those silver cups bothered him.)

The Relations are also not the final word on the order’s activities. This was an educated order with considerable sophistication in astronomy and mathematics. Much information about their astronomical observations in Canada bypassed the Relations entirely and ended up in such publications as G.B. Riccioli’s Almagestum Novum of 1651 and Astronomiae Reformatae of 1665. And while the Relations never say anything explicit about the Canadian mission owning – or losing – a particular astrolabe, they do contain strong internal evidence of an astrolabe’s use.

We know the Jesuits paid attention to latitude – in addition to the maps they produced, they occasionally mentioned latitude figures in the Relations. And as well as wanting to know latitude for its own sake, they needed it to calculate (through spherical trigonometry and celestial observation) the local time, so that they could observe lunar eclipses in their efforts to determine the longitude of Ste. Marie in Huronia. Any doubt that the Jesuits were making some of their own latitude determinations is swept away by the following statement in the Relation of 1642 (Volume 21) for the Huronia mission by Jerome Lalemant:

According to the latest and most exact observation which we have been able to make, our new house at Sainte Marie (which is in the midst of the Huron country) is in forty-four degrees and about twenty-five minutes of latitude.” This statement about making a latitude observation is as strong as anything by Champlain himself. The position of 44 degrees 25 minutes for Ste-Marie was off by a reasonable 19 minutes.(9)

But I don’t think even the Jesuits would have relied on the old-fashioned, undersized Cobden astrolabe for astronomical observation. The device did have two unusual features that would have given it another use by them: as a surveying instrument. Its full diameter is divided into four quadrants (90 degree scales), where most mariner’s astrolabes only have a scale on the upper half, and some only in one upper quadrant. It is also unique in having the (lost) ring at the bottom.

The full scale meant it could have been employed horizontally in surveying, a feature that would have extended its useful life. While the ring is thought to have supported a weighted chain to steady it in a breeze, I believe this was actually in part a plumb line, which would allow precise positioning of the device as vertical angles were measured in order to calculate the height and/or distance of an observed point. Such a tool would come in handy in laying out a mission site, and particularly in assessing topography. The full-diameter scale could be used to measure angles below horizontal – in other words, downhill. At Ste. Marie, the Jesuits had to plan drainage culverts, and they also produced a clever aqueduct that brought water to the mission from a nearby spring.

The fact that this astrolabe was instead attributed exclusively to Champlain, and continues to struggle to gain a provisional Jesuit attribution despite long-standing weaknesses in the Champlain provenance, testifies to the natural warps in cultural perspective. Imagine if the Jesuit martyr Jean de Brebeuf had been the leading historical figure from the seventeenth century when the astrolabe was discovered (which he wasn’t, partly because he wasn’t canonized until 1930). Someone would have tried to press those communion cups – which also would never have been melted down – into his hands. The astrolabe would not have been the main prize but an associated curiosity, easily explained by what was known even then of Jesuit expertise in astronomy and cartography. Instead, the Jesuit provenance literally was thrown away, and the ownership debate, focusing exclusively on the astrolabe, tracked immediately toward an emerging secular hero: Champlain.

• • •

Which still leaves us with the problem of how Champlain produced such rotten latitude figures for both Gould’s Landing and Morrison Island in 1613. That he dead-reckoned his way from the first position to the second on a meandering diagonal course during a two-day portage that gave him “much trouble,” producing a precise northerly distance between them, seems unlikely, although Professor Heidenreich feels it was within Champlain’s capability.

I have another idea: that the explorer simply fudged the offending latitude figures in the Voyages by bumping up his true sightings exactly a full degree. No one, it appears, has ever questioned how this great navigator could have made the first glaring mistake, at Gould’s Landing, so close to his previous latitude sighting at Chaudière Falls, and not have noticed. Publishing the figure for Chaudière Falls indicates he was rightly satisfied with it, as he was only out by 12 minutes. If a latitude reading of 46 degrees 40 minutes really was produced at Gould’s Landing, Champlain immediately would have realized: that’s the same as my base at Quebec. For he had produced a latitude of 46 2/3 for his nascent settlement at present-day Quebec City in 1609. Accepting the Gould’s Landing sighting also required him to accept that, over a short stretch of the Ottawa River, he had somehow crabbed northwards 62 minutes, when in fact he had only gained 8 minutes. A navigator with not half his skill would have pronounced absurd the idea that, in just two days since leaving Chaudière Falls, he had gone almost 112 kilometres north, when his compass, the sun’s westerly trajectory, and common sense told him he had paddled about sixty-five kilometres west. I don’t think the navigator capable of dead reckoning along the difficult portage past the Calumet rapids could be the same navigator who failed to tweak to the illogic of his Gould’s Landing latitude fix.

There are two possible explanations for deliberate deception, beyond a desire to mislead his Dutch and English exploration rivals. The first involves the past significance of latitude 46 in Champlain’s affairs. The fur trading monopoly awarded by the French crown to his original benefactor, Dugua de Mons, in 1603, specified a territory between latitudes 40 and 46. Champlain had undertaken the journey up the Ottawa in 1613 under a new commission, received in November 1612 when de Mons arranged to have Henri de Bourbon, a cousin of the French king, appointed Viceroy of New France. [Note: I was in error here. de Mons had nothing to do with the new commission. It was arranged by Champlain.] While latitude figures weren’t mentioned in the new monopoly, latitude 46 may have survived as a geographic tripwire in Champlain’s mind.

The new monopoly was hugely unpopular with French independent traders, particularly in St-Malo, and they did their best to oppose it and discredit Champlain personally. Having pressed into virgin territory in 1613, and with no other European witnesses to his progress except a translator he identified only as Thomas and the controversial Vignau (whose credibility Champlain would aggressively discredit), Champlain may have wanted to assert he had progressed above latitude 46 in order to prepare the way for establishing, should it be politically necessary, a trading monopoly that was separate from the disputed one based on the St. Lawrence.

Secondly, he could have fudged the latitude figures to keep his investors interested in continuing to pursue a profitable midcontinental route to a northern sea that ultimately would lead to the Orient. The latest monopoly was granted not just for furs, but also for the purpose of discovering and exploiting the speculated passage. And as Champlain lamented in his Voyages when forced to turn back at Morrison Island, “This northern sea cannot be farther off than 100 leagues of latitude; for I was in latitude 47.” He was actually still below latitude 46, and I think he knew it.

In 1618, Champlain proposed to the Paris chamber of commerce that “One may hope to find a short route to China by way of the River St. Lawrence. …it is certain that we shall succeed in finding it without much difficulty.” How much of that bravura was salesmanship on which Champlain knew he couldn’t deliver, and how much was genuine conviction on his part, is up for debate. But the published errors in his latitude sightings in 1613 seem to point not to a lost astrolabe, but to a misplaced integrity. And those silver cups that emerged from the bank of Buttermilk Creek along with the astrolabe in 1867 point right at the Jesuits.

The author would like to acknowledge the cooperation and advice of Conrad Heidenreich, Jean-Pierre Chréstien, Peter Broughton, and Randall Brooks in the development of the ideas in this article.


1 Every degree of latitude represents almost 113 kilometres (70 statute miles) on the earth’s surface, so for increased accuracy, a degree is divided further into 60 minutes, which were sometimes expressed by Champlain as simple fractions of a degree. (Every minute is further divided in to 60 seconds, but Champlain never measured these.)

2 The fact that the Cobden astrolabe also has degrees marked around its full diameter is revealing. Most mariner’s astrolabes limited the degree markings to the upper half, or even one upper quadrant. The Cobden device had four inscribed quadrants. The standard instruction manual for the mariner’s astrolabe in the late sixteenth century held that two quick consecutive sightings of the sun should be taken, with both ends of the alidade. The two results would then be averaged, to reduce any errors in the device’s construction. But if, as with with Cobden model, you had a scale for both ends of the alidade when taking a sighting, you could verify the alignment of the alidade immediately and not have to try to get a confirming fix, which might be impossible to achieve while the ship rolled and heaved in rough weather.

3 Champlain’s published latitude figures are, at the same time, real curiosities. All of his results are published in either fractional degrees or expressed in minutes that convert readily to basic fractions. In some cases, it appears he arrived at these fractions by averaging the results of different observations, perhaps from different instruments or collected on different days or even by different people – for example, averaging half a degree and one third of a degree, or one-quarter and one-third. A “pure” sighting from a given day should have, in at least a few occasions, produced results expressed in minutes that could not be reduced to a basic fraction, since declination corrections involved single minutes, and probability says that, sooner or later, he was going to have a final result like thirty-three minutes. I suspect Champlain processed his results in some way, perhaps in preparation for cartographic plotting, and that even finer results remained in his notebook. Heidenreich has noted that Champlain’s mean errors in his cartography were smaller than those of his published latitudes.

4 Although mariner’s astrolabes were developed by the late fifteenth century, becoming larger and more precise throughout the sixteenth, by about 1600, the English were producing ones with complex calculating abilities. One example from 1616 hints at the sort of sophisticated instrument Champlain would have preferred for his cartographic efforts. The St. Andrew’s University mariner’s astrolabe is about 39 centimetres in diameter (15.5 inches) and has a transversal scale inscribed below the main degree divisions, which would allow positions as fine as one-sixth of a degree (ten minutes) to be determined.

5 In the register of known mariner’s astrolabes at England’s National Maritime Museum which scholars use, the Cobden find, NMM 8, is called the “Champlain (Hoffman) Astrolabe.”

6 The astrolabe is housed in a domed display whose signage simply says “Astrolabe.” One of the four illuminated descriptive panels has a map tracing a speculated route of Champlain’s 1613 portage, and says no more than that “certain nineteenth century authors” attributed the device to Champlain.

7 Samuel Eliot Morison suggested a connection to both the Jesuits and Champlain in his 1972 Champlain biography. Noting that Champlain had willed an astrolabe to the head of the Jesuit mission in Canada, Charles Lalemant, Morison proposed that the Cobden astrolabe was in fact Champlain’s, but that Lalemant was the one who lost it on the Upper Ottawa portage! While Charles Lalemant never actually made a trip up the Ottawa, his relatives in the Jesuit order – his brother Jerome and his nephew, the martyr Gabriel – did serve in the Huronia mission, and they, or some other member of the order, could have done the losing. But Morison never addressed the problem of how an astrolabe so small could have produced Champlain’s published latitude figures – a shame, since Morison’s great strength as a biographer of maritime explorers was his own nautical experience.

8 “Seventeenth-Century Maps of the Great Lakes: An Overview and Procedures for Analysis.” Archivaria, No. 6 (summer 1978).

9 It seems more than coincidental that Lalemant timed a lunar eclipse at Ste-Marie on April 14, 1642, the same year for which he offered the latitude figure in the Relations. Four years later, Francesco Giuseppe Bressani (an Italian professor of mathematics who is also credited with creating a well-executed map of New France in 1657), observed a lunar eclipse at Ste-Marie with a telescope, and achieved errors in the local time of the eclipse’s phases of less than one minute – an astonishingly accurate result.