THE SMFTHSONIAN INSTITUTION. 247 



publication. This work was commenced at the close of 1851, aiid 

 has been prosecuted with considerable vigor during the past year. It 

 was given by me in charge to Mr. Lorin Blodget, of Western New 

 York, who has engaged in the work with much ardor, has devoted to 

 it his whole time and attention, and has evinced an unusual degree of 

 talent for investigations of this character. 



The results which have thus liu" been obtained are of interest to the 

 science of meteorology, and valuable to the practical arts of" life. The 

 following is a descriptive list of the deductions presented in a tabular 

 form : 



Temyeratiirc Tables. 



1. Tables of general mean temperature for a series of years, em- 



bracing a summary of the annual means lor the years 1849, 

 1850, 1851, and J 852, with a general summary of reliable obser- 

 vations of mean temperature on the North American continent. 



2. Tables of mean temperature for eacli month, season, and year, fijr 



1849, 1850, 1851, and 1852, embracing 273 stations in 1849; 284 

 in 1850 ; 300 in 1851 ; and 39G in 1852. 

 •3. Tables of mean temperature at each observed hour for the same 



periods and the same stations. 

 4. Tables of the monthly extremes of temperature, with the range above 

 and below the monthly mean, for the same periods and the same 

 stations. 

 •5. Collection of tables of temperature at different stations, observed for 



a series of years. 

 •6. Miscellaneous tables of temperature, not conforming entirely to either 

 . of the above divisions. 



The first class of tallies embraces six hundred and seventy stations, 

 distributed over tlie entire continent, from the West Indies and Mexico 

 to the Polar seas. 



The second class has a more limited range, and is generally confined 

 to the United States and its territories, as observed by the military sys- 

 tem, and that of tlie Smithsonirm Institution, with a few stations in 

 Canada and the British possessions on this continent. 



The third class of tables is nearly the same in extent with the pre- 

 ceding, and for three complete years, viz : — 1850, ]85], and 1852. 

 The fourdi class is of the same extent and time. 

 The fifth is a climatic arrangement of tables from various stations, 

 extending in continuous series over periods varying from five to sixty 

 years. 



Ta bles of Pi -ec ipilation . 



1. Tables of distribution of precipitation in rain and melted snow for 



each month, season, and year, for 1849, 1850, 1851, and 1852. 



2. General tables of precipitation for a series of years, containing the 



results of the preceding tables, with a general summary of all 

 reliable and accessible observation of fall of rain on the North 

 American continent. These tables give results from about lour 

 hundred stations, principally in the United Slates, its Territories, 

 and the West Indies. 



