800 



SIGNAL SERVICE. 



cent. ; and during the year ending June 30, 

 1872, 354 cautionary signals were issued, with 

 an estimated percentage of correctness amount- 

 ing to 70. These results also afforded the best 

 elucidation and the most complete demonstra- 

 tion of the law of storms and the movements 

 of cyclones that had ever heen obtained in any 

 country. 



By act of Congress approved June 10, 1872, 

 the Signal Service was charged with the duty 

 of providing such stations, signals, and re- 

 ports as might be found necessary for extend- 

 ing its research in the interests of agriculture. 

 The agricultural societies over the land ear- 

 nestly entered into and cooperated with the 

 Service in this new development of its inquiries 

 and reports. Eighty-nine such societies, thirty- 

 eight boards of trade or chambers of com- 

 merce, numerous scientific institutions, col- 

 leges, and leading professional men put them- 

 selves in communication with the Chief Signal 

 Officer, with a view to facilitate this branch of 

 his work. The scientific societies at home and 

 abroad began to take the liveliest interest in 

 the general labors of the Office, and to express 

 the highest approval of the results attained. 

 And, beyond the limits of the United States, 

 numerous marine observations, which General 

 Myer had previously desired, with the purpose 

 of studying the atmosphere as a unit both on 

 the ocean and the land, were forwarded regu- 

 larly to his office. 



The expansion of the work in 1873, under 

 the stimulus of a world-wide favorable notice, 

 was even more rapid than in the previous year. 

 On March 3d Congress authorized the estab- 

 lishment of Signal Service stations at the light- 

 houses and life-saving stations on the lakes and 

 seacoast, and made provision for connecting 

 the same with telegraph-lines or cables "to 

 be constructed, maintained, and worked under 

 the direction of the Chief Signal Officer of the 

 Army, or the Secretary of War, and the Secre- 

 tary of the Treasury." Early in this year the 

 Office also began the regular publication of a 

 " Monthly "Weather Review," summarizing all 

 its data and showing the results of its investi- 

 gations, as well as presenting these in graphic 

 weather-charts adapted to the comprehension 

 of the unscientific part of the communities it 

 was destined to reach. The library of the Sig- 

 nal Office was increased to some 2,500 volumes 

 bearing on the special scientific duties imposed 

 upon it. The tests of meteorological instru- 

 ments previously instituted enabled it to great- 

 ly improve and simplify its entire instrumen- 

 tal apparatus at all stations. The percentage 

 of verification of its predictions for the year 

 ending June 30, 1873, was for each geographi- 

 cal division as follows : 



New England 81-50 



Middle States 8MT 



South Atlantic States 79'92 



Lower Lake region 78-90 



Upper Lake region. 75'25 



Eastern Gulf States 77'16 



Western Gulf States 74-40 



Northwest.... 74' 00 



It was in September of this year also that, 

 at the proposal of the Chief Signal Officer in 

 the International Congress of Meteorologists 

 convened at Vienna, the system of world- wide 

 cooperative weather-research, since then so 

 extensively developed, was inaugurated, and 

 began to contribute its observational data to 

 the Signal Office records. Thus, in his report 

 for 1873, the Chief Signal Officer was able to 

 say of its labors, " Their utility is no longer 

 questioned, and effort at home and' abroad 

 turns only toward their development." The 

 Service was now no longer an experiment, but 

 an assured success. 



The operations of this division of the Signal 

 Service, popularly known as the " Weather 

 Bureau," have been, every year since its crea- 

 tion, somewhat enlarged by Congress, until 

 they have become numerous and varied. The 

 first to be specially mentioned is the daily work 

 of weather-prediction, including storm-warn- 

 ings. These are issued from the office of the 

 Chief Signal Officer three times every day, un- 

 der the title of " Indications " and " Caution- 

 ary Signals," and are based upon three series 

 of simultaneous weather-reports telegraphed 

 to Washington from all parts of the United 

 States and Canada. The observations are 

 taken simultaneously at all stations at 7 A. M., 

 3 P. M., and 11 p. M., and at once put upon the 

 wires. The number of stations from which 

 tri-daily telegraphic reports are received at the 

 central office is 133. Telegraphic reports have 

 been also regularly received from one West 

 India station, and during the hurricane season 

 from five. The total number from which such 

 reports are received daily is 159 ; but, includ- 

 ing those sent by mail, it is much larger ; 

 while the total of reporting stations within the 

 United States territory, including the special 

 river and sunset stations, on the 30th of June, 



SIGNAL SERVICE STATION ON THE SUMMIT OF MOUNT 

 WASHINGTON. 



1879, was 229. The vertical range of the ob- 

 servations extends from sea-level to the sum- 

 mits of Mount Washington (6,286 feet) and 

 Pike's Peak (14,151 feet). 



