60 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



the polar areas, while in extra-tropical seas it is considerably 

 higher, having been raised by the prolonged evaporation to 

 which it has been subjected in moving toward them. 



THE ANNUAL EEPOET OF THE CHIEF SIGNAL OFFICEE OF THE 



ARMY FOE THE YEAE 1873. 



The report of the Army Signal-office for the year ending 

 November 1, 1873, has been recently published separately 

 from the report of the Secretary of War (of which it forms a 

 part), and constitutes a volume of about nine hundred pages. 

 According to the report, the service has during the year ex- 

 tended its operations in every direction, including several new 

 and thoroughly novel departments of labor. Passing over 

 the details of the organization of the service, we note that 

 seventy-eight stations are now established in the United 

 States, being an increase of thirteen during the year. In ad- 

 dition to these, five others have been temporarily occupied 

 for special investigations. Reports are also received from 

 eleven stations in the Dominion of Canada. These are re- 

 ceived through Professor Kingston, of Toronto, chief of the 

 Meteorological Bureau of the Dominion. Stations are also 

 occupied in the West Indies, at Havana, Kingston, and San- 

 tiago. Twenty special stations have been established upon 

 the Mississippi River and its confluents, for the purpose of 

 furnishing in detail the river reports upon which the navi- 

 gation of those waters so much depends. The publications 

 of the office consist of 



1st. Tri-daily bulletins of synchronous observations. 



2d. Tri-daily weather maps, with the accompanying syn- 

 opses and probabilities. 



3d. The daily Post-office bulletin. 



4th. The cautionary storm-signals. 



5th. The cautionary river flood dispatches. 



6th. The regular daily river reports. 



7th. The weekly chronicle, published each day of the week 

 for the preceding seven days. 



8th. The monthly weather review, with its accompanying 

 charts of storm-tracks, isobars, isotherms, winds, rain-fall, etc. 



9th. The monthly book of synopses, probabilities, verifica- 

 tions, and facts. 



10th. The annual report, embracing meteorological results 



