In the case of alleged showers of “paper” the material has been found to be the crusts of dried algæ, which form on the surface of the ground exposed by the evaporation of the water of shallow ponds.
6. THE YEAR WITHOUT A SUMMER
The Weather Bureau is a bureau of information, and one of the ways in which it strives to give a good account of itself is by answering endless questions about “the year without a summer.” This title has been given to the year 1816.
Blodget, in his “Climatology of the United States,” tells us that all the summers from 1811 to 1817 were cold in this country, and that in every month of the summers of both 1812 and 1816 snows and frosts occurred in the Northern States. It is the latter summer, however, that has lived in popular tradition. The year 1816 is known further as “poverty year,” or “eighteen hundred and froze to death.” It acquired the name of “mackerel year” in New Hampshire, where people ate mackerel as a substitute for pork, little of which was fattened on account of the extreme scarcity of corn. Western Europe, also, had a cold summer in 1816, and the year as a whole seems to have been a cold one over a great part of the world.
Sources of information about the cold summer in this country, besides Blodget’s book above mentioned, include Perley’s “Historic Storms of New England,” which devotes a whole chapter to the subject, and Charles Peirce’s “Weather in Philadelphia.” Peirce tells us that at Philadelphia “there was ice during every month of the year, not excepting June, July, and August, There was scarcely a vegetable came to perfection north and east of the Potomac.” According to the “Monthly Weather Review,” citing the recollections of James Winchester, of Vermont: “It is said that in June of that year snow fell to the depth of three inches in New York, Pennsylvania, and New Jersey on the 17th; five inches in all the New England States, except three inches in Vermont. There was snow and ice in every month of this year. The storm of June 17 was as severe as any that ever occurred in the depth of winter; it began about noon, increasing in fury until night, by which time the roads were impassable by reason of snowdrifts; many were bewildered in the blinding storm and frozen to death.... There was a heavy snowstorm August 30th.... The year 1816 had neither spring, summer, nor autumn. The only crop of corn raised in that part of Vermont that summer was saved by keeping bonfires burning around the cornfield night and day.”
At the time of its occurrence the frigid weather of the summer of 1816 was popularly attributed to sun spots, which were big enough to be seen with the naked eye in May and June. A present-day hypothesis on the subject has been mentioned in our chapter on atmospheric dust. The dust cloud from the eruption of Tomboro, in 1815, was so vast that for three days there was darkness at a distance of 300 miles from the volcano.
A proximate cause of the cold summer is perhaps to be sought in an unusual intensity and extent of the area of low barometric pressure which is more or less permanently located in the vicinity of Iceland and, as one of the principal atmospheric “centers of action,” has a great deal to say about the weather of the countries adjacent to the North Atlantic. Dr. C. F. Brooks has called attention to the fact that the Arctic navigator, Scoresby, found unusually mild and open weather that summer in the seas east of Greenland. This would be explained by strong southerly winds, forming part of the “counter-clockwise” circulation around the Iceland low; and if the same pressure system extended its influence to our shores, persistent cold northwest winds might be expected to result over the northeastern United States.
7. INDIAN SUMMER AND THE ICE SAINTS
Indian summer weather is an undeniable fact. Every inhabitant of the northern United States and southern Canada is familiar with the mild, calm, hazy state of the atmosphere that frequently occurs in the autumn, sometimes following a brief period of unseasonable cold known as “squaw winter.” It is, however, one thing to recognize the existence of a certain type of weather as characteristic of our autumns, and quite another to admit that one definite spell of such weather occurs more or less regularly from year to year. One true summer, and only one, comes to pass each year, and occupies an approximately fixed place in the calendar. Even the so-called “year without a summer,” which we have just described, was merely a year in which the regular annual rise of the temperature curve was less marked than usual. Indian summer, on the contrary, has never been tied down to a particular part of a particular month. In his notes on the meteorological conditions at Concord, Massachusetts, during the ten years, 1851–1860, Thoreau records the occurrence of Indian summer weather on dates all the way from September 27 to December 13; a range of 77 days.
The belief in the definite occurrence, year after year, of what has sometimes been called the “after-summer” is not peculiar to America. It prevails also in Europe, where this supposed period of renewed warmth has been assigned to certain dates, owing in part to its association with the names of particular saints in the calendar. These dates vary widely, however, from one region to another, ranging from August 15 (Julian calendar), the beginning of the “young women’s summer” of Russia, to November 15, St. Martin’s day, a date popularly associated with after-summer in Germany, Holland, France, Italy, and sometimes England.