POPULAR MISCELLANY, 



715 



since 1755 when December and January 

 were warmer than the mean. The warm 

 seasons come at irregular intervals, and 

 do not suggest any law ; seventeen of them 

 came between 1755 and 1821, and seventeen 

 between 1821 and 1884. In seventy-six per 

 cent of these exceptional winters, the month 

 of November also was warmer than usual. 

 Herr Hellman asserts that the chances are 

 eighty-one to nineteen that a warm Febru- 

 ary will follow a warm December and Janu- 

 ary, and fifty-seven to forty-three that the 

 same will be the case with March. Thus, 

 the chance is that a winter that begins by 

 putting on a mild face in November will 

 preserve the same aspect all through. In 

 regard to the seasons following these ex- 

 ceptional winters, Herr Hellman finds that 

 a moderately mild winter is more frequently 

 followed by a cold spring, and a very warm 

 winter more usually by a warm spring ; and, 

 in general, that the warmer the winter the 

 warmer will be the ensuing spring. These 

 conclusions contradict popular notions. 



Pbysiographie Conditions of Mnnesota. 



— In a lecture on the " Physiographic Con- 

 ditions of Minnesota Agriculture," recently 

 delivered before the State Horticultural So- 

 ciety, Professor C. W. Hall claimed for that 

 State a nearly central position on the North 

 American Continent, as fixed by lines drawn 

 from Eastport to Astoria, and from Behring 

 Strait to the Isthmus of Panama. Of its 

 area, 83,365 square miles, 78,600 square 

 miles are land, while the rest of the ter- 

 ritory is occupied by some 8,000 or 10,000 

 lakes ; 48,000 square miles are forest, and 

 31,000 prairie. Not quite 40,000 square 

 miles are drained into Hudson Bay, and 

 7,689 square miles into the St. Lawrence, 

 while the rest of the area of the State 

 sheds its water into the Mississippi. The 

 height of the land ranges from 602 feet 

 above the sea, at Lake Superior, to 2,400 

 feet in the highest part of the Mesabi, or 

 dividing range between the water-sheds, 

 and averages, for the whole State, perhaps 

 about 1,200 feet. Much of Minnesota is 

 covered by the drift, the various constitu- 

 ents of which — granites and schists, sand- 

 stones, clays, and limestones — have been 

 ground up and mingled in utter confusion^ 

 so that the land is adapted to the greatest 



diversity of crops. The average annual rain- 

 fall is about 28-27 inches, or about three 

 quarters of an inch less than the average for 

 the whole United States, excluding Alaska. 

 The average January temperature is nearly 

 12° Fahr., while the July average is nearly 

 71° Fahr; and the difference between the 

 warmest summer day and the coldest winter 

 night is about 120° Fahr. A reduction in 

 the average temperature is observed of one 

 degree for every 350 feet of additional ele- 

 vation. As in Nebraska, a gradual increase 

 in rainfall appears to be taking place as more 

 of the prairie-soil is brought under the plow ; 

 and the streams are becoming larger, and 

 springs are flowing where once water could 

 not be obtained. 



An Absolute Unit of Liglit. — An abso- 

 lute standard for the measurement of the 

 intensity of light has long been wanting. 

 All the standards heretofore proposed are 

 imperfect, because in none of them has 

 it been possible to secure complete uni- 

 formity in intensity and color. A satis- 

 factory standard should be identical at all 

 times and in all places ; should be of con- 

 venient size; and should be white enough 

 to be comparable with all modem lights in 

 every region of the spectrum. These con- 

 ditions appear to be fulfilled in the stand- 

 ard proposed by M. Tiolle in 1881, which, 

 after some improvement in processes, has 

 been definitely adopted by the International 

 Congress of Electricians. It is the light 

 emitted by a square centimetre of melted 

 platinum at the temperature of solidifica- 

 tion (1,775° C, or 3,227° Fahr.). This light 

 nearly resembles the incandescent electric 

 light, and is constant during the whole pro- 

 cess of solidification. Its value, expressed in 

 one of the old standards, is 1 carcel = ^-^ of 

 the Violle unit. 



Birds' Tastes for Color and DInsie. — Mr. 



E. E. Fish has published in the "Bulletm " 

 of the Buffalo Naturalists' Field-Club a pa- 

 per on " The Intelligence of Birds," in which 

 he ascribes to birds a keen perception of 

 color and capacity to be gratified by artis- 

 tic arrangements of colors, and a strong sus- 

 ceptibility to musical melodies. Evidence 

 of the enjoyment of color is given by the 

 tasteful combinations with which many birds 



