SIGNAL SERVICE. 



811 



SIGNAL SERVICE ANEMOMETER, WITH SELF-REGISTERING ATTACHMENTS. 



The importance of accurate anemometers was 

 recently illustrated in the storm which over- 

 whelmed the Tay Bridge in Scotland, carrying 

 a passenger-train into the tempest-lashed Firth 

 with instant and total destruction ; an accident 

 which, in the judgment of many, would never 

 have occurred had the bridge-constructors and 

 railway authorities possessed anemometric in- 

 struments showing the real velocity and force 

 of the gale. In some American storms the 

 wind has been found to blow with the tre- 

 mendous velocity of from 100 to 138 miles per 

 hour ; and it is difficult to find or frame an 

 anemometer which, while delicate enough to 

 register small disturbances, will be strong 

 enough to stand the force of such hurricanes. 

 But the experiments of the Signal Service, it is 

 hoped, will lead to pome instrumental improve- 

 ments in this direction. 



But the great question, as respects instru- 

 ments, with which the Signal Service has been 

 concerned, is to obtain barometers, thermom- 

 eters, etc., which will be self-recording, and 

 give without manipulation continuous, exact, 

 and graphic registers of the atmospheric fluc- 

 tuations. Numerous ingenious contrivances of 

 this kind as Hough's electric meteorograph 



and printing barometer, Wild'* 

 barometer, and Gibbon's baro- 

 graph have been for yeara 

 under careful testing by the 

 office, with the view of secur- 

 ing forms adapted to general 

 use on stations, and also to 

 obtain an instrument so fitted 

 with apparatus and electric 

 wires attached thut its action 

 at a remote point may be auto- 

 matically registered on paper 

 in the Washington office. Al- 

 though much lias been done 

 to settle this question, it is yet 

 unsolved, and it awaits further 

 experimentation. 



The International Weather 

 Service. This novel and vast 

 extension of the national work 

 done by the United States 

 weather service is perhaps the 

 most remarkable practical re- 

 sult of the development of 

 modern meteorology. Pre- 

 vious to the introduction of 

 the system of " simultaneous " 

 weather - reports by General 

 Myer in 1870, no observations 

 were taken in any country 

 that could be strictly called 

 synchronous, suitable for the 

 preparation of synoptic wea- 

 ther-charts, or that could be 

 regarded as strictly inter-com- 

 parable ; but, in each country 

 where weather -reports on a 

 large scale were made, they 

 were prepared from daily ob- 

 servations made at moments of time more or less 

 widely separated. Under the old observational 

 methods, concert among the nations in meteo- 

 rological work was practically out of the ques- 

 tion. Not until the new method of simulta- 

 neous observations had been put to the test, and 

 a feasible system devised in which all nations 

 could codperate, was it possible to combine 

 their investigations of the weather into one 

 grand and uniform scheme, for the purpose of 

 observing the a&rial envelope of the globe as a 

 unit. To do this required not only a uniform- 

 ity in the instruments employed, but also a 

 simultaneity in the hours for reading the instru- 

 ments; that is, that weather-observers all round 

 the globe should take their observations at one 

 and the same fixed moment of physical time. 

 The organization and successful working of a 

 weather bureau upon such a simultaneous sys- 

 tem in the United States prepared the way, 

 however, for an international weather service. 

 Accordingly, when in September, 1878, an In- 

 ternational Meteorological Congress was con- 

 vened at Vienna an assemblage composed of 

 the official heads of the meteorological bureaus 

 of the different powers an original proposi- 

 tion was made by General Mycr, as the Chief 



