6 70 The Smithsonian Institution 



of one of them l that of the eight sources of information from 

 which the tables were derived, the 300 and over folio volumes 

 of the registers of the Smithsonian Institution was a single 

 source. They were published in the Contributions to Know- 

 ledge. In this connection mention must be made of the 

 "Three Rain Charts of the United States, showing the dis- 

 tribution by Isohyetal lines of the mean precipitation in rain 

 and melted snow: (i) for the summer months, (2) for the winter 

 months, (3) for the year" (1870); ''Temperature Chart of 

 the United States, showing the distribution, by isothermal 

 lines, of the mean temperature for the year" (1873) ; "Three 

 Temperature Charts of the United States, showing the dis- 

 tribution by isothermal curves of the mean temperature of 

 the lower atmosphere: (i) for the summer months, (2) for the 

 winter months, (3) for the year" (1874); "Temperature Chart 

 of the United States, showing the distribution of isothermal 

 lines of the mean temperature for the year (1874); and a 

 Base Chart of the United States" (1880). All of which 

 were published by the Smithsonian Institution in the years 

 indicated by the parenthesis. 



Mention has already been made of the valuable collection 

 of Meteorological Tables, by Arnold Guyot, the fourth edition 

 of which was published in 1884. This edition was exhausted 

 in a very few years, and Secretary Langley then decided to 

 recast the work entirely and publish it in three parts, one of 

 meteorological, one of geographical, and one of physical tables, 

 each representative of the latest knowledge in the field and 

 independent of the others, but the three forming a homogene- 

 ous series. The " Smithsonian Meteorological Tables," the 

 first volume of the new series was issued in i893. 2 



Among the early volumes of the " Contributions to Know- 

 ledge" are numerous papers containing discussions of meteor- 



1 "Smithsonian Report," 1875, page 25. 2 Ibidem, 1894, page 9. 



