A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Hearne & Worsley's Navigation
From: Ken Muldrew
Date: 2005 Jan 24, 11:16 -0700
From: Ken Muldrew
Date: 2005 Jan 24, 11:16 -0700
On 23 Jan 2005 at 16:13, Kieran Kelly wrote: > I am ashamed to admit that I had not heard of Hearne who fought under Hood > in the Napoleonic Wars and preceded Thompson by decades into the Canadian > northwest. In fact, in 1784 Thompson arrived at Churchill as an apprentice, where Hearne was the master, and spent a year there. He copied out some of Hearne's journal but otherwise seems not to have held any great affection for the man. > Why is this significant here? This list has spent some considerable time > comparing the methods and results of Thompson in Canada, Lewis and Clarke > in the US and A C Gregory in Australia but both Hearne and Worsley seem to > have escaped everyone?s attention. Has anyone out there looked closely at > their results, techniques etc. Unfortunately both these books are a bit > short on the very fine technical detail, which would interest many. > > For example Hearne in 1769/70 carried (and broke) two quadrants - a > Hadley?s Portable and an Elton?s the latter being much inferior apparently. > While reading the book I was a bit confused about how he took his sights as > no artificial horizon was mentioned. However a line from his journal > explained that he had broken the bubbles on both quadrants rendering them > unusable. This surprised me ? were bubble artificial horizons used on > quadrants in the 1700?s? In Hearne's journal of his trip to the Arctic Ocean, he relates the following in his introduction: "Mr. Dalrymple, in one of his pamphlets relating to the Hudson's Bay, has been so very particular in his observations on my Journey, as to remark, that I have not explaine the construction of the Quadrant which I had the misfortune to break in my second Journey to the North. It was a Hadley's Quadrant, with a bubble attached to it for a horizon, and made by Daneil Scatlif of Wapping. But as no instrument of the same principle could be procured when I was setting out on my last Journey, an old Elton's Quadrant, which had been upwards of thirty years at the Fort, was the only instrument I could then be provided with, in any respect proper for making observations with on the land." He goes on to say that while Dalrymple criticizes him for only taking a single latitude, he had actually taken four but little thought that anyone would be interested in them. So it's clear that he was using a spirit level for his horizon. The only example I know of in the journal of an actual observation is: "This gave us an opportunity of endeavouring to ascertain the latitude by a meridian altitude, when we found the place to be in 63?10' North nearly. It proving rather cloudy about noon, though exceeding fine weather, I let the quadrant stand, in order to obtain the latitude more exactly by two altitudes; but, to my great mortification, while I was eating my dinner, a sudden gust of wind blew it down; and as the ground where it stood was very stoney, the bubble, the sight-vane, and vernier, were entirely broke to pieces, which rendered the instrument useless." > Also Hearne was observing for longitude but did not appear to have a > chronometer. Does anyone know how he did this? Does McGoogan actually claim Hearne observed for longitude? There is no mention of even a pocket watch being taken on his journey and his quadrants were not even suitable for latitudes. When Hearne quotes a longitude in his journal, it seems pretty obvious that it comes from ded reckoning. > Furthermore on checking a map he seems about 280 miles out in his > estimation of the latitude of the mouth of the Coppermine River. This is a > serious error ? about 467kms. As a comparison research I am undertaking on > the Australian Gregory shows his average latitude is out by about 400 > metres, with a maximum error so far of 1.5 kilometres. How could Hearne > have got it so wrong when otherwise he seemed a superb navigator and > explorer? Hearne was guided by the Indians to the mouth of the Coppermine river and back by way of Lake Athabasca. As an explorer he was first rate, but I'm not aware of any navigational expertise. He could have learned navigation the year before his journey as William Wales and Joseph Dymond arrived at Prince of Wales fort in 1768 to observe the transit of Venus the following year. But with neither a watch nor a nautical almanac, longitudes would have been impossible even if he had a quadrant that was in working order. McGoogan is an afficionado of Arctic travel so perhaps he has some new material that sheds more light on Hearne's navigational abilities. I'll have to get the book. Ken Muldrew.