Dr Richardson on the Frozen Soil of North America. 



117 



Severn Outpost, i Severn River, 

 Lat. 56^00'N. west side of 

 Long. 86° 15' W. Hudson's Bay, 



Autumn, 



Frozen earth at the depth of 5| feet in 

 compact blue mud. The frozen stra- 

 tum was cut into 7 \ feet, when a snow 

 storm put an end to the operation. 

 Pit 13 feet deep. 



The river bank is 30 feet high, and on 

 cutting into it, to make a quay, the 

 frost was found extending downwards 

 till it reached high-water mark, at 

 which point the earth was soft, as far 

 as the experimenter could penetrate 

 horizontally. 



York Factory, 

 Lat. 57°00'N. 

 Lon ? .92°26'W. 



West side of 

 Hudson's Bay, 

 5 miles from 

 the mouth of 

 Hayes' River, 



Oct. 

 1835, 



Surface water solid. New frost tothe 

 depth of 8 inches. Soil, blue tenacious 

 mud, with boulders. Pit 30 yards 

 from the river. Thaw 3 feet from 

 surface. The digging into the perma- 

 nently frozen stratum continued for 

 fourteen days, when the thawed earth 

 was again reached at the depth of 20£ 

 feet from the surface, leaving 17ifeet 

 of permanent frost, beneath which 

 the temperature of thawed mud was 

 found by repeated trials to be + 33° F. 



Fort Simpson, 

 Lat. 62°ll'N. 

 Lon. 121° 32 W. 



Influx of the 

 south branch of 

 the Mackenzie 

 into the main 

 stream, about 

 80 yards above 

 the level of the 

 Arctic Sea, 



Oct. 19. 

 1836, 



Pit 80 yards from the banks of the river. 

 Soil heavy, sand and clay mixed. 

 Thawed surface soil 10 feet 7 inches. 

 Frozen substratum 6 feet 3 inches. 

 8 feet more through a loose sandy soil, 

 and a rod thrust 4 feet deeper into the 

 bottom. In all 29 feet. A thermo- 

 meter kept at the bottom of the pit 

 shewed a higher temperature than one 

 exposed to the air. The mean tem- 

 perature of October here is about + 23° 

 F. Mean annual heat + 25° F.* 



» These facts ascertained partly by verbal communications with the experimenter, Mr Murdoch 

 M c Pherson. 



Our previous knowledge of the depth to which the summer thaw penetrates, or the 

 ixt nt of the frozen substratum in North America, was very limited. 



At Fort Franklin on Great Bear Lake, the summer thaw, on the 5th of October 

 182.1, had penetrated 21 inches into the sandy platform on which the house was built. 

 The frozen substratum was dug into about 6 feet, but its total depth was not ascertained. 

 Fort Franklin is supposed to stand about 230 feet above the sea-level. The mean heat 

 gf the year 1825-6 waa + 17-G1 3 F., and of the first ten days of October + 19.4° F. On 

 the '.Mli of the same month the .small lakes were frozen over, and on the 11th, the snow 

 lying on the ground put an end to the further action of the sun on the soil for that season. 



July 5. 182C— On the east bank of the Mackenzie, in Lat. 68° 37' N., a hole was 

 fag in tlio sandy soil, at the foot of the Rein -deer Hills, to the depth of 3 feet, without 

 reaching the frozen soil. 



July 17. 182C— On an island of the Arctic Sea, Lat. 70° 10' N. ; Long. 129° 15' \V., 

 < ompoaed of sand and slaty clay, the thaw had penetrated scarcely a foot. 



July 28. 1837.— In Lat. 70° 50' N., on the coast to the westward of the Mackenzie, 

 Mr Pease found the soil thawed only to the depth of 4 inches. 



IfoVAI. NaVAI. IIoslM'l Al A I BEABLAB, 



20//, A'.„v,„/„r 11(40. 



