22 REPORT OF THE SECRETARY. 



1848; and the next warmest, July, 1838. The mean annual amount 

 of rain is 40.38 inches, distributed with considerable regularity. The 

 month in which the most rain falls, on an average, is August ; and 

 that in which the least falls is February. 



Another paper in the twelfth volume of Contributions is a series 

 of meteorological observations, similar to the preceding, made at Wash- 

 ington, Arkansas, by Dr. Nathan D. Smith. 



The place at which these observations were made is on the summit 

 of the dividing ridge between the waters of the Red river and those of 

 the Washita, fifteen miles northeast of Fulton and twenty south of 

 the Little Missouri. From this ridge there is no higher level for a long 

 distance; but to the northwest there is a gradual ascent for about fifty 

 miles, to the foot of the mountains. 



The records are of observations of the temperature at sunrise through- 

 out the year, and at 2 p. m. in the winter, and 3 p. m. in the summer; 

 amount of rain, and remarks on the weather; with the daily mean 

 temperature, and monthly mean, maximum, minimum, and range, 

 from January 1, 1840, to December 31, 1859, a period of twenty years. 

 Appended to these observations are tables giving the following summa- 

 ries for each month and year and for the whole series of twenty years : 



1. Extremes of temperature. The highest temperature at sunrise and 

 at 2 or 3 p. m. ; the mean temperature of the warmest day; the lowest 

 temperature at sunrise and at 2 or 3 p. m. ; and the mean temperature 

 of the coldest day. 



2. Variations of temperature. Range of temperature at sunrise and 

 at 2 or 3 p. m., and of the daily mean temperature; the extreme range 

 of temperature ; the greatest rise and fall of temperature from sunrise 

 of one day to sunrise of the next day ; the greatest rise and fall from 

 2 or 3 p. m. of one day to 2 or 3 p. m. of the next day. 



3. Mean temperatures. Means at sunrise and at 2 or 3 p. m. ; of 

 months, years, and seasons ; and of each day, as deduced from the 

 observations for the whole twenty years. 



4. The amount of rain for each month and year, and monthly and 

 annual means for the whole series. 



These tables, as in the case of those for Providence, furnish a series 

 of interesting facts. For example : the mean temperature of the whole 

 period is 61.81°; the warmest month is July, the coldest January; the 

 warmest year was 1854, the coldest year was 1843. The coldest New 

 Year's day recorded was that of 1840, the mean temperature of which 

 was 22°; the warmest 1846 and 1855, the mean temperature of each 

 being o1°. From these tables it appears that the coldest day in the. 



