group rests unconformably on the Huronian Series, which reposes also unconformably upon the Laurentian Series. The Huronian Series is 18,000 feet thick, and consists of quartzites, thin limestone bands, slate rocks and diorite. It is the lower copper-bearing rock of America. The immense beds of iron ore at Marquette also belong to this series. It is traversed by a vast number of trappean dykes. The Laurentian system is the oldest known system of rocks, and is composed of gneiss, crystalline limestone and Labradorite. This series is of enormous thickness, one band of limestone being 1,000 feet thick, and the entire mass of altered sediments composing the vast Laurentian series probably exceeds 20,000 feet. Traces of fossils have been found in several localities; beds of iron ore hundreds of feet thick, great veins of metallic sulphurets with widely distributed crystalline limestone bands, give great economic importance to the series. The geographical surface of Canada contains about 80,000 square miles of unaltered fossiliferous rocks, and probably 230,000 square miles of the Laurentian Series. Where the Laurentian Series is not covered with quarternary deposits, the belts of crystalline limestones, and soda and lime feldspars, produce upon disintegration a fertile soil, so that the cultivable area in the Laurentian country is much greater than would be inferred from the gneissoid character of the formation in many districts. THE CLIMATE OF CANADA. The geographical position of Canada has necessarily a remarkable influence upon the climates of different parts of the country. The western peninsula has its climate greatly modified by the vast lakes which almost encircle it. The valley of the St. Lawrence below Kingston, as far as tide water, is removed from this ameliorating influence, and the country below Quebec is subject to many of those vicissitudes which belong to great estuaries and the sea-coast. The north shores of Lake Huron and Superior, and the back country north of a line extending from Lake Huron to Ottawa, and removed from the influence of the great lakes, possess a very rigorous climate, in which intense winter cold, prolonged through many weeks, is followed by a short but hot summer, succeeded by genial autumnal months. Meteorological observations have been carried on for many years, at three separate points, which may represent the centers of the different climates of Canada in the settled parts of the country. At TORONTO, (1862,) the mean annual temperature for a period of 22 years, has been 44°.12, the warmest month, July, has a mean of 66°.85; the coldest month on the average of 22 years is February, which has a mean temperature of 22°.98. The highest temperature recorded was 99°.2, the lowest,-26°.5. The average range of temperature during the same period amounts to 102°.7. The average fall of rain during 21 years was 30.32 inches. The greatest rain-fall in one month was 9.76 inches, the greatest in one day, 3.36 inches; but the average for 21 years of the greatest rain-fall in one day is 2.14 inches. The average fall of snow for 21 years is 61.6 inches, and the number of days on which snow falls is 57. The total average depth of snow and rain during 21 years is 36.49 inches. The average number of days on which rain or snow falls is 163. September is the most humid month. The resultant direction of the wind during a period of 14 years is N. 60 W. The mean velocity per hour being 1.85 miles; but without regard to direction, the mean velocity is 6.78 on an average of 14 years. The mean humidity of May, June and July, deduced from a period of 21 years, is 74. At MONTREAL, (1856,) the mean temperature of the air for a period of 7 years, was 41°.56. The absolute mean range for the same period has been from 90°.9 to 27°.4 below zero. The highest temperature in the shade recorded was 100°.1, the lowest 36°.2 below zero, giving a climatic range of 136°.3. The degree of humidity is represented by .84. The average number of days on which rain fell was 73 per annum, and of days on which snow fell 43; or in all, 116 days on which precipitation took place. The rain-fall amounted to 43.004 inches; the depth of snow to 95.76 inches, or 52,380 inches of precipitation reduced to the form of rain. The mean of evaporation from the surface is nearly 21 inches during the spring, summer and autumn. The most prevailing wind is the westerly. The snow storms are from the N. E. by E., on the average. The following table shows the monthly mean temperature at four different stations between the head of Lake Ontario and Quebec inclusive. From it an idea of the difference in climate between those far separated points may be inferred. The period over which the observations extend is the year 1855, but it is probable that the means of a large number of years would produce slight but comparatively unimportant changes in the observed temperatures. From this table the chief differences in the climates of the districts of which they are centers may be deduced. TABLE Of the Mean Monthly Temperatures at Hamilton and Toronto, (Upper Canada,) and Montreal and Quebec, (Lower Canada,) for the year 1855. The year 1855 was distinguished by the extreme and prolonged cold of February. 1855, 38.09 -25.00 92.08 -33.09 97.00 -29.05 .90.00 TABLE Showing the average Temperature, Humidity, Wind, Rain and Snow at Toronto, 108 feet above Lake Ontario, or 341 feet above the sea, for a period of 22 years: (Observatory, Toronto, PROFESSOR KINGSTON, DIRECTOR.) } Extremes in 9 years. 62, in 1861. 57, in '53 '56. Dec. 1857. Lowest. when the mean of the month was when the mean of the month was Least cloudy month.............July and Aug. July, 1853. June, 1861. 45 75 83 34 73 45 |