American Scientist

In the last three of my Marginalia columns I described the adventures, successes and failures of astronomers who in the 18th century set out across vast expanses of the then relatively unexplored world to observe Venus on two of the rare occasions it comes between the earth and the sun and so is seen to transit the solar disk. The reason for such extreme endeavors was that those observations, if made from widely separated places on the earth, would lead to a greatly improved estimate of the scale of the solar system. This, we now know, would form the next step in an ongoing ladder of distance scales that would eventually reveal our place in our Milky Way galaxy, and the scale and age of the universe itself. Also, the immense efforts to observe these transits in 1761 and 1769 were in part inspired by the knowledge that no further such transits would take place until 1874 and 1882, and after those there would be none until 2004 and 2012.

Having looked at the adventures of the 1761 expeditions, as well as the horrors of Le Gentil's ill-fated travels for both transits, we here consider two of the other 1769 expeditions.

You may recall that Jean Chappe d'Autoroche succeeded in observing the 1761 transit from the town of Tobolsk in Siberia, having spent much of a Siberian winter getting there by sled, as well as narrowly escaping a lynch mob when an early thaw that flooded the town was said to be caused by his interfering with the sun. Nevertheless, he volunteered to observe the 1769 transit, asking only relief from snow and ice. The Académie Royale des Sciences in Paris obligingly sent him to Baja California.

Plague

Chappe's entourage was slight. Besides Chappe himself, it included an artist, a clock maker and a man named Pauly, described as an engineer-geographer. Two Spanish assistants were added for political reasons, and the party sailed from Cadiz on March 8, 1768, hoping to reach their assigned site before the transit some 15 months later. Getting across the Atlantic alone took 77 days, and after landing at Mexico's east-coast port of Vera Cruz, the group set off northwestward to cross nearly 1,000 kilometers of wild terrain. Pauly, who would be the sole survivor of the expedition, writes of "high mountains, dreadful precipices, dry deserts . . . . We came near dying a thousand times. We were besides crushed by an excessive heat which hardly left us strength enough to drag ourselves around," especially after the heat ruined their food supply and left them to live off the countryside.

Two months of this brought them to "San Blas, on the rosy sea" some 200 kilometers south of Mazatlán. There followed six weeks of navigating 500 kilometers of the Gulf of California to reach San José del Cabo at the southern tip of Baja California ("so dangerous that nobody ever dared to land thither . . . because of perpetual waves foaming with rage against rocks"). Despite the foaming waves (one sometimes suspects Pauly of laying it on a bit thick) they got themselves and their equipment ashore with 13 days to go before the transit on June 3, 1769. That was the good news. The bad news came when "some savage people . . . informed us that a most dreadful epidemic was laying waste to the country." The expedition was advised to move immediately at least a hundred leagues (450 kilometers) to the north, but they had yet to unpack, clean and set up their instruments; there was no time for more travel. They stayed where they were.

Chappe's observations of the transit were among the best made of either transit anywhere in the world. Moreover, his subsidiary astronomical observations to establish the latitude and longitude of his site (crucial to the final analysis) were done with an accuracy unprecedented in arduous fieldwork.

But already the epidemic had the expedition in its grip. Pauly writes, "We used to feel the most unspeakable pains, and every one of us . . . was wishing most anxiously for death as a supreme cure. You would hear all around but heavy groanings; every day used to carry away some of our Companions." Chappe himself died on August 1. "We were all dying, myself and my companions, when I closed up his eyes…. Our situation did not allow us to attend to his funeral with many ceremonies."

Pauly, now default leader of those left, packed up "all the papers concerning the object of our voyage . . . in a casket which I directed to the Viceroy of Mexico. I begged most earnestly some savages of good standing . . . to see that it would reach its place in the case we should all pass away, and to tell the Viceroy to have it shipped [to the Academy in Paris]."

Pauly, clutching the casket, and the remaining two expedition members set off on the fearful journey homeward in September. These other two both died en route, and Pauly himself had to pause for strength, sometimes months at a time, before finally arriving in Paris a year later on September 5, 1770. "I hasted to the Academy the observations made in California. That body of men has bestowed on me the highest Eulogy . . . ." The king, Louis XV, awarded Pauly a pension of 800 francs a year. Sadly, though, it seems he remained an invalid, and eventually had to petition for an increased pension.

Life on the High Arctic

The Royal Society of London organized two expeditions for the 1769 transit. One of these had as its leader William Wales, at one time a computing assistant at the Royal Observatory in Greenwich. Aware of Chappe's horrific experiences in the Siberian winter preceding the 1761 transit, Wales requested a warm and not-too-distant site. The Royal Society sent him to Fort Prince of Wales, a Hudson's Bay Company fur-trading post in northern Canada. Even today, as the town of Churchill, Manitoba (population 1,143), on the coast of Hudson Bay, it has no road link to the rest of Canada and is famous for its polar bears. As to payment, Wales and his assistant, Joseph Dymond, would be paid £200 if, upon their return, their work was judged well done.

Still, the journey was to be straightforward. There were regular sailings of Hudson's Bay Company ships to and from the trading post, so there would be no unpleasant overland treks for Wales and Dymond. On the other hand, pack ice limited the shipping season to two months at Fort Prince of Wales, and it would only begin after the June 3 transit. Thus they would have to be there in the late summer of 1768 and winter over. They sailed from England on June 23, 1768.

By July 18 they were crossing the Labrador Sea and entering the Hudson Strait, well north of 60 degrees latitude. On the 19th they "passed within a cable's length of a very large island of ice . . . [it] was adorned with spires; and indented in the most romantic manner that can be imagined." Navigating the islands of the straits, they had their first meeting with the Inuit people when "Eskimaux in their canoes, or, as they term them, Kiacks" came alongside. Wales was intrigued by their clothing, especially that of the women, which included "boots [that] come up quite to their hips, which are there very wide, and made to stand off from their hips with a strong bow of whalebone, for the convenience of putting their children in. I saw one woman with a child in each boot top."

July 27: "This evening I told 58 islands of ice . . . ." Two days later the ship was among the remnant floes of the pack ice. "It is really very curious to see a ship working amongst ice. Every man on board has his place assigned him; and the captain takes his in the most convenient one for seeing when the ship approaches very near the piece of ice which is directly a-head of her, which he has no sooner announced, but the ship is moving in a quite contrary direction, whereby it avoids striking the piece of ice [directly] . . . . In this manner they turned the ship several times in a minute; the wind blowing a strong gale all the time . . . ."

And then there were the weird atmospheric effects of the high Arctic. On August 7 they caught their first glimpse of Cape Churchill, and yet "though we saw the land extreamly plain from off the quarter deck, and, as it were, lifted up in the haze; yet the man at the mast head declared he could see nothing of it. This appeared so extraordinary to me, that I went to the main-top-mast-head myself to be satisfied of the truth thereof; and though I could see it very plain both before I went up, and after I came down, yet could I see nothing like the appearance of land when I was there."

Happily, though, on August 9 the ship worked its way up the estuary of the Churchill River, and at two o'clock "she was safe moored." The local officials "behaved to us with great civility," and soon the visitors were exploring their surroundings. "Mr Fowler was so kind as to walk with us about ten miles up the country, which, as far as it went, was nothing but banks of loose gravel, bare rocks, or marshes . . . . Our errand was, to see if we could not find some land likely to produce corn; and in all that extent we did not find one acre, which, in my opinion, was likely to do it." What they did soon find, however, were "three very troublesome insects. The first is the moschetto, too common in all parts of America . . . to need describing here. The second is a very small flie . . . . These in a hot calm day are intolerably troublesome: there are constantly millions of them about one's face and eyes, so that it is impossible either to speak, breathe, or look, without having one's mouth, nose, or eyes full of them…. The third insect is much like the large flesh-flie in England; but, at least three times as large: these, from what part ever they fix their teeth, are sure to carry a piece away with them, an instance of which I have frequently seen and experienced."

Also, of course, there was very little by way of building materials. This they had anticipated by bringing with them a complete observatory and cabin for living quarters, which they now hastened to reassemble "having hitherto had no where to lie but on the floor." They set up and tested their observing equipment, and made some of the necessary auxiliary astronomical observations.

The hot calm days and insects soon gave way to intimations of winter. September 9 brought two inches of snow, and by mid-October "we began to put on our winter rigging; the principle part of which was our toggy, made of beaver skins: in making of which, the person's shape, who is to wear it, is no farther consulted, than that it may be wide enough, and so long that it may reach nearly to his feet."

On November 6 "the river, which is very rapid, and about a mile over at its mouth, was frozen fast over from side to side, so that the people walked across it . . . . Also the same morning, a half-pint glass of British brandy was frozen solid in the Observatory."

"In the month of January, 1769, the cold began to be extremely intense: even in our little cabbin . . . in which we constantly kept a very large fire . . . . The head of my bed-place, for want of knowing better, went against one of the outside walls of the house; and notwithstanding they were of stone, near three feet thick, and lined with inch boards, supported at least three inches from the walls, my bedding was frozen to the boards every morning; and before the end of February, these boards were covered with ice almost half as thick as themselves." Their sleep was constantly interrupted "by the cracking of the beams in the house, which were rent by the prodigious expansive power of the frost. But those are nothing to what we frequently hear from the rocks . . . along the coast; these often bursting with a report equal to that of many heavy artillery fired together, and the splinters thrown to an amazing distance."

March finally brought relief from the cold, and by the end of April "the ground was in many places bare," and the hunters started preparing for the spring goose season. Wales and Dymond turned their attention to final preparations for the coming transit of Venus on June 3.

One would guess that the chances of clear weather at that site on that date would not have been much better than 50–50, but as it happened, all went well. There were cloudy intervals during the six-hour transit, but at the crucial times of ingress and egress "the Sun's limbs [were] extreamly well defin'd," and the astronomers' observations proved a great success.

The ice in the river finally broke up on June 16, allowing a spate of salmon fishing ("I have known upwards of 90 catched in one tide . . . ."), and Wales and Dymond enjoyed a generally relaxed summer while awaiting the supply ship due in late August. They sailed in early September, and after a relatively calm voyage, were back in London on October 19. Wales, however, was greatly angered when a British customs officer confiscated his much-prized toggy, moose-skin shoes and other items of Hudson's Bay Company winter clothing. As always, engaging in a violent argument with the customs officer did no good at all.

Little is known of Dymond, and not much more about Wales, but Wales did later accompany Captain James Cook on his second and third voyages to the Pacific. He ended his career teaching mathematics at Christ's Hospital School in London. Among his students were Samuel Taylor Coleridge and Charles Lamb, one of whom remembered Wales as "a good man of plain, simple manners, with a large person and a benign countenance." There have been worse epitaphs.

My next column will be the final one in this series. It will deal with the most famous expedition of the 1769 transit, that of James Cook to the South Pacific, and also summarize the scientific outcome of all the transit observations. How well did they do in improving our knowledge of the scale of the solar system? Had it all been worth it?

© J. Donald Fernie

Acknowledgment

I am indebted to Professor Emeritus Dael Wolfle of the University of Washington, whose great-great-uncle was Pauly, for sending me a translation of an unpublished manuscript of Pauly's with permission to quote from it. Professor Wolfle has donated the original document to the Special Collections Department of the University of Washington Library.