IN RAIN AND SNOW, IN THE UNITED STATES. 139 



the annual fluctuation of the wind for each given direction. To be of value such 

 tables must extend over a long series of years. 



At Marietta, Obio, for which place I have discussed 1 the relative frequency and 

 the relation of wind to rain, the results are in entire accordance with the rain charts ; 

 the summer rains are accompanied by S. W. and W. winds, and the winter rains 

 by E. and S. E. winds. The relative frequency of the S. W. reaches a maximum 

 in July, and that of the S. E. a minimum in December or January, in accordance 

 with the rain curve at this place. A similar correspondence between the charts 

 and the rainy directions can be traced at Brunswick, Me. ; 2 here I found the rainy 

 wind in winter to be the N. E., and in summer the S. E., also the S. W., and less 

 frequently the N. E. 



At Toronto, Canada West, the diagram of the observed annual fluctuation is of a 

 remarkable zigzag character and of small range (see Plate 2, bottom); its most 

 expressive feature is a minimum about the close of winter. The very elaborate 

 tabulation of meteorological results at the Toronto Observatory, 3 by G. T. Kingston, 

 Director, shows that the winds most accompanied by rain or snow are from the 

 E. N. E., E., E. S. E. and S. E. in winter, and from the E. N. E., S. W., and W. S. W. 

 in summer, as observed between 1853 and 1862. There are consequently two 

 opposing rainy directions in summer. The annual variation in the relative frequency 

 exhibits one or two maxima, and as many minima. 



Distribution of Rainy Days in the Year. — The number of rainy days in a year 

 was collected from the records, and tabulated to be available in the shape of averages 

 for each month, and for various geographical positions. Less time was expended 

 in this collection than in that of the amount for two reasons: First, it became 

 evident that all observers are not agreed in the manner of recording days of pre- 

 cipitation. While some only note days of settled or continuous rains, others include 

 all days of precipitation, even if hardly a measurable amount fell, and days, other- 

 wise clear, on which thunder and rain storms occurred, lasting but a small fraction 

 of an hour. Storms of the latter kind, for instance, frequently pass in summer, 

 over this city from the westward, in the afternoon, with remarkable regularity, for 

 a number of days in succession, and if the average temperature be increasing they 

 will occur earlier each succeeding day. It is proper to make a distinction, by 

 separate entries, between these two extreme cases, and thus the differences in 

 records may be greatly reduced. In some records, where rainy and snowy days are 

 given separately, the number of days of precipitation becomes doubtful when it 

 rains and snows on the same day. In the first two Army Registers it would seem 



1 Smithsonian Contributions to Knowledge (120). Results of Meteorological Observations made 

 at Marietta, Ohio, between 1826 and 1859, by S. P. Hildreth, M. D., etc. etc. Washington, June, 

 1868. 



3 Smithsonian Contributions to Knowledge (204). Results of Meteorological Observations, made 

 at Brunswick, Me., between 1807 and 1859, by P. Cleaveland, L.L.D., etc. etc. Washington, June, 

 1867. 



8 Results of Meteorological Observations made at the Magnetical Observatory, Toronto, Canada, 

 W., during the years 1854 to 1859 inclusive, also during the years 1860-1-2. Two volumes. 

 Toronto, 1864. 



