9
amination of these tables it will be seen that the proposition which I have advanced is incontestably true. In one of the recent reports the fact is stated, and philosophically accounted for as follows:—"For though there is absolutely more heat at the latitude of New Orleans during the year than at Madison, Wisconsin, yet there is more heat received at this latter place, during the three months of midsummer than in the same time at the former place."
In the same report, and accompanying it, is a table showing the sun's diurnal intensity at every ten degrees of latitude. It further says:—"On the 15th of June the sun is more than 23 degrees north of the equator, and therefore it might be readily inferred that the intensity of heat should be greater at this latitude than at the equator; but that it should continue to increase beyond this even to the pole, as indicated by the table, may not at first sight appear so clear. It will, however, be understood when it is recollected that though in a northern latitude the obliquity of the ray is greater, and on this account the intensity should be less, yet the longer duration of the day is more than sufficient to compensate for this effect, and produce the result exhibited."
As an illustration of the position, observations made in Alaska, near the Artie Ocean, in the country recently purchased by the United States from Russia, show an astonishing summer heat. In the northern district of Youkon, where the surface of the ground thaws in summer to the depth of three or four feet, as stated in the Agricultural Report for 1868, the greatest degree of cold ever known in this territory was 70 degrees below zero:—"I have seen the thermometer at noon at Fort Youkon, not in the direct rays of the sun, standing at 112 degrees, and I am informed by the commander of the post that several spirit thermometers, graduated to 120 degrees, had burst under the scorching sun of the Arctic midsummer, which can only be appreciated by one who has endured it. In midsummer on the upper Youkon, the only relief from the intense heat, under which vegetation attains an almost tropical luxuriance, is the two or three hours during which the sun hovers near the northern horizon; and the weary voyager in his canoe, blesses the transient coolness of the midnight air. Fortunate it is for our Northern States and the Canadas, that the heat of their short summers should be so decided; for otherwise their cereals would not ripen, and a dense population of intelligent, vigorous, and enterprising men, could not be sustained there. On this subject the distinguished Mr. Lippincott, of New Jersey, remarks in his essay on the "Geography of Plants," embodied in the agricultural report for 1863: "The aggregate of heat (which a plant requires) may be received during a shorter term in high latitudes, because of the greatly increased length of the day, and the processes hastened and maturity attained at an early day. This is well illustrated in the growth of Indian corn, which is said to be remarkably accommodating; though it must have a semi-tropical heat where-ever grown. The extraordinary high temperatures experienced in certain Northern localities, remote from the ocean, and the intense calorific and chemical action of the sun's rays, enhanced by the extreme length of the days of summer, enables this plant to mature in high northern latitudes.
Great Britain and Canada.
An Englishman, judging solely from experience at home, I dare say, is astonished at the position I assume. But you must recollect that you live upon an island enveloped in aqueous vapour, and that you are shielded from the hot rays of the sun in summer.
Americans sometimes maliciously say, that they have been six weeks in England without seeing the sun, and when it did appear, it looked like a "boiled turnip;" and that the only ripe fruit they ate here was a boiled apple.
