THE INTERNATIONAL WEATHER-SERVICE. 291 



ment of actual (not local) time,'''' as was stated on every weather-map. 

 This conception aimed at the rescue of meteorological researches from 

 that disorder and disconnectedness which had always characterized the 

 observational work. The prime object was to gain a daily conspectus 

 of the atmosphere over the country as it actually was, and as it would 

 be seen if a photographic view of it, so to speak, could be taken. The 

 simultaneous method, when announced, seemed so natural and simple 

 that one might have wondered that any other was ever attempted. 

 Observations called " synchronous " had been, indeed, before this time, 

 energetically made in several countries ; but the term " synchronous " 

 was used to signify that every observer read off his instruments at 

 given hours of his own local time, and not at the same moment of 

 physical time. Etymologically, there might be little or no difference 

 between " synchronous " and " simultaneous," but, for all the jjurposes 

 of atmospheric investigations over a vast territory like that of the 

 United States, the practical difference was by no means insignificant. 

 When observers, who on the old " synchronous " method reported the 

 weather-status each at the same hour of local time, were separated by 

 hundreds of miles, their reports failed to represent the actual fluctu- 

 ations of the atmosphere and the true bearings of its cyclonic and anti- 

 cyclonic movements ; so that, when the meteorologist came to compare 

 and chart the combined data, they yielded necessarily a distorted or 

 untrue picture of the ever-restless aerial ocean. On the other hand, in 

 the " simultaneous " method, since all the observers over the wide field 

 of the research read their instruments at one and the same moment 

 (7.35 A. M. Washington mean time), their reports, when charted, gave 

 a true and life-like representation of the physical phenomena as they 

 actually coexisted and conspired. As on the screen of the artist's 

 camera the sun instantly paints the true image of the human face 

 before its expression can be changed, so does the process of simul- 

 taneous observation seize and secure all the elements necessary to de- 

 lineate the current physical features and conditions of the atmosphere, 

 as existing at o. fixed moment, and before they can have time to un- 

 dergo change. Simple as this expedient is, it is evidently the key to 

 all effective research in a vast gaseous ocean whose currents and waves 

 are ceaselessly rolling and rapidly altering their geographical bearings, 

 even while the sun is quickly passing from one meridian to another. 

 W^ere all the weather observers of the world to read off their instru- 

 ments as it were by a given tick of one clock, their collective data 

 would furnish materials for the most exact delineations of the complex 

 atmospheric machinery which it is possible to obtain. Instead of piling 

 up a mass of weather bulletins unsuited for purposes of a rigidly 

 scientific inter-comparison, as was so long done,* they would contribute 



* In the old system of telegraphic weather-reports established by the Smithsonian 

 Institution, the observers reported at 8 a. m., 2 p. m., and 9 p. m., each at his own local 

 time. Accordingly, their reports could not give exact results. To take a not uncommon 



