Arctic searching expedition : a journal of a boat-voyage through Rupert's Land and the Arctic Sea : in search of the discovery ships under command of Sir John Franklin / by Sir John Richardson.
- John Richardson
- Date:
- 1852
Licence: Public Domain Mark
Credit: Arctic searching expedition : a journal of a boat-voyage through Rupert's Land and the Arctic Sea : in search of the discovery ships under command of Sir John Franklin / by Sir John Richardson. Source: Wellcome Collection.
Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.
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![age-road is, in fact, nearly level; the inequalities being of small account as far as to the sudden descent of the Cockscomb. In the sandy soil there are many fragments of sandstone, a few of limestone, and scattered boulders of granites, sienites, and green- stones. The deposit of sand is about six hundred feet deep, and most probably incloses solid beds of sandstone. It is based on a (Devonian ?) limestone, which lines the whole bed of the Clear- water River, till its junction with the Elk River, as I shall here- after mention.* Captain Lefroy assigns fifteen hundred feet as the elevation of the surface of Methy Lake above the sea,f and, from various esti- * As the Cockscomb is under the level of the brow of the valley, the depth of sand may be more than 600 feet at i'ts highest points. t The exact height assigned by Captain Lefroy to Methy Lake is 1540 feet, which I have reduced in the text to the even number of 1500, as agreeing better with my own estimates. If this be nearly correct, Captain Lefroy gives too small an altitude to Isle a la Crosse Lake, since the route from thence to the portage is chiefly lake-way; and the Methy Hiver can not have a descent of 240 feet, which his altitudes would assign to it. In the year 1848, I made several observations with the aneroid on Methy Portage to ascertain its levels, but they were neither so carefully made nor so extensive as they would have been, had I been less anxiously and con- stantly employed about the transport of the goods and boat. The error in this case is not, however, likely to be many feet, as the portage is evident- ly very nearly level as far as the Cockscomb. The height of the latter was ascertained on July 27, 1849, by Delcros' barometer, the observations be- ing as follows : Six feet above Clear- Hour. A.M. Delcros' barom. Millimr. + 0-34 cor. for general error. Red. to Eng. inches. Red to temp. 32° Att. T Centr. herm. Fab.. Det. Th. h.m. 4 0 4 46 5 20 72-7] 9 71-079 72-740 72-753 71113 72-774 28-644 27-998 28-652 28-606 27-944 28-591 6-4 10-2 11-4 43-5 50-4 525 40-8 50-9 51 0 Two feet above Cocks- Six feet above Clear- These furnish two sets for calculation, The first giving a height of 640 feet. And the second of 632 The aneroid barometer in 1848, gave 631 Mean 634 Sir Alexander Mackenzie estimated this declivity at 1000 feet, Lieuten- ant Hood at 900 feet, both judging merely from the eye and time em- ployed in its descent.](https://iiif.wellcomecollection.org/image/b21074458_0083.jp2/full/800%2C/0/default.jpg)
