MISCONCEPTIONS CONCERNING THE WEATHER 133 



occur about the time of the autumnal equinox, September 21, when 

 the sun crosses the celestial equator to the southern hemisphere. East 

 of the Bocky Mountains rain occurs on an average about once in three 

 or four da5^s, while in the North Pacific states it occurs once in every 

 two or three days, taking the year as a whole. Throughout these large 

 areas the latter part of September is a transition period, with autumn 

 conditions replacing those of summer, and occasionally with the first 

 occurrence of a storm of the winter type. The latter are usually char- 

 acterized by relatively high winds, rain on two or three successive days, 

 and followed by a considerable fall in temperature. Bearing in mind 

 the average frequency of rainy days and of winter storms, it is apparent 

 that it would be abnormal should no rain occur during the week preced- 

 ing or the week following September 21. The so-called equinoctial 

 storm is a fiction, 



Indian Summer is another popular superstition. Characterized 

 by high temperatures, light winds and calms, and a hazy or smoky 

 atmosphere, it is generally supposed to be a particularly pleasant period 

 of indefinite length occurring in October or November. That there is 

 frequently a return of summer-like conditions during the late autumn 

 can not be denied. But to affirm that Indian Summer is a period of 

 several weeks in duration, recurring each autumn, and easily recognized 

 by the occurrence of heat, calms and haze, can not be proved by clima- 

 tological records. It is a peculiar fact that while the recurrence of 

 summerlike conditions in autumn has given rise to this tradition, and 

 even the name as a season, the similarly frequent recurrence of winter- 

 like conditions in spring has not been popularly recognized. Summer- 

 like periods in autumn and winterlike periods in spring can in every 

 individual case be explained by the weather map in terms of barometric 

 distribution, paths of storms, resulting winds and calms, the height of 

 the sun, the length of days, and the unequal distribution of heat over 

 the continent and the bordering oceans. 



Another false notion, particularly common in rural districts, is the 

 belief that various animals, through some particular dispensation of 

 Nature, have a previous knowledge of coming weather changes. As 

 a result, many proverbs have arisen, based upon observations of the be- 

 havior of animals. For example, it is sometimes stated that a cold 

 winter is portended when the musk-rat or the beaver builds the walls 

 of his home thicker than usual, or when the squirrels or the non- 

 migratory birds hide large quantities of food during the autumn. 

 Again, the remark is often made that a storm is imminent when the 

 chickens go to roost early or when the house-cat seeks a warm place 

 beside the fire. Even the human feeling of comfort occasionally gives 

 rise to presentiment. Persons afflicted with recurrent rheumatism claim 

 to feel the approach of a storm long before it appears, and people of 



