ILLINOIS HORTICULTURAL SOCIETY. 293 



studied the monthly mean temperature ; highest and lowest degrees, 

 range of temperature, warmest and coldest days. Next is cloudiness 

 determined by estimate, ten being perfect cloudiness or any variation 

 of cloudiness, representing fractional parts. There is much interest 

 attached to the study of the clouds, and to cloud formations. The 

 mean cloudiness for the year is four and fifty-five hundredths, represent- 

 ing a state not quite e(iual to a sky half overcast. 



The winds next claim attention. The prevailing winds during the 

 year have been west, and their prevalence also indicate quite correctly 

 the storm quarter ; the point from whence comes gales, hurricanes, 

 and severe rain storms. • The average wind force is two or four 

 miles per hour. Alas, as with the joys of the world, clouds pre- 

 dominate largely over sunshine ; the whole number of fair days 

 amounting to one hundred and fifty-one, while the cloudy days reach 

 two hundred and fifteen. Of rainy days there were fifty. Rain and 

 snow fell on seven days, while snow fell on twenty-six days ; the snow- 

 fall giving a depth of twenty-six and one-half inches. The mean rain- 

 fall was thirty-eight and fifty-eight hundredths inches. The month of 

 October produced no rain, what has not occurred for twenty-one years. 



The comparative view of the temperature of the season gives us a 

 more distinct idea of the climate than, taken as a whole, by mean an- 

 nual computations — Spring, Summer, Autumn, and Winter. The four 

 quarters of the year are determined astronomically by the relation of 

 the movements of the sun, in the ecliptic. The passage of the sun 

 across the ecjuator brings on greater length of days than nights, and 

 marks the vernal equinox, or inauguration of Spring, which occurs the 

 twenty-first of March. The Summer solstice ushers in Summer on the 

 twenty-first of June, and the Winter solstice leads in Winter on 

 the twenty-first of December. Our almanac divisions are not astro- 

 nomically true. 



Our season has been marked by a long-continued drouth, which 

 made the year, in many particulars, a very unsuccessful one for horti- 

 culture, as well as for all branches, directed to the cultivation of the 

 soil. Insect life, in many forms, thrive most favorably during dry sea- 

 sons ; they multiply and extend their ravages to almost every species 

 of fruit, m spite of our best-directed energies for their extinction. 



OSCILLATIONS AND CASUAL PHENOMENA. 



While the seasons progress, under the earth's annual changes of 

 surface to the sun, we may note a steady and ujnvard tendency of tem- 

 perature in spring, and as marked evenness in its decline in autumn. 

 But, while many of the phenomena of climate are regular in their ap- 

 pearance, and are not marked by any particular severity, oscillations 

 come upon us almost without time for preparation to meet their onset. 

 I allude to sudden atmospheric waves, which have broken over the 

 shores of Oregon and British Columbia, from time immemorial, and 

 spent their fury upon portions of the continent lying easterly from the 



