298 THE POPULAR SCIENCE MONTHLY. 



neous Observations " is a generalization in itself, and offers the meteor- 

 ologist every day a hird''s-eye view of the aerial world as it actually 

 was at that fixed moment of physical time when all the observations 

 embodied in it were made. Nothing can be simpler or more intelli- 

 gible to even unscientific eyes than a chart which, by means of sugges- 

 tive symbols, displays the different elements of the weather over a 

 hemisphere, each in its own color. Just as Mercator's projection rep- 

 resents the entire ocean to the mariner — as if there were no horizon or 

 sphericity — and all objects in their true meridional bearings to each 

 other, so the " International Weather-Chart " depicts the aerial ocean in 

 its beautiful integrity and all its parts in their true jjhysical relations 

 to each other, as certified by strictly simultaneous reports. Of course, 

 the two charts are entirely independent and different ; but we refer to 

 the invention of the old Flemish geographer merely to illustrate and 

 enforce the immense value of every really synoptic chart as a weapon 

 of research and as a medium of scientific discovery. 



The cartographic method, by which truly synoptic views of the 

 atmosphere are obtained, is indeed the natural accompaniment and 

 handmaid of the method of "simultaneous weather-reports," both of 

 which are peculiar to the national weather-service inaugurated at 

 Washington in 1870, and, through the adoption of General Myer's 

 proposition at Vienna, in 1873, extended to the new international 

 weather-sei*vice. Without " simultaneous " weather observations, it is 

 obvious, no truly " synoptic " weather-chart is possible ; and, as has 

 been said, the first " simultaneous " observations were those instituted 

 by the United States in 1870. The unique and novel feature of the 

 international weather-charts, and the feature which will most commend 

 them to meteorologists, is that they furnish a faithful pictorial history 

 of the atmosphere and its revolutions, enabling the inquirer to trace its 

 currents and counter-currents, to witness the behavior of its cyclonic 

 storms and other barometric waves as they traverse continents and de- 

 ploy upon the ocean, and to form clarified conceptions of its massive 

 yet orderly machinery. The well-known English journal of science, 

 " Nature," " earnestly hopes that the navies and the mercantile vessels 

 of all nations will soon join in carrying out this magnificent scheme of 

 observations, originated by the Americans in 1873, and since then fur- 

 ther developed and carried on by them with the highest ability and 

 success." Its French namesake, " La Nature," said recently, when 

 speaking of this service, " One ought not to be surprised to learn that 

 the United States, encouraged by their first successes, are to attempt a 

 new extension of a system of observations which has already, in so few 

 years, produced considerable results." It would not be an easy task 

 to predict the future results to be obtained by such a system of investi- 

 gation ; but we may confidently conclude that no system of weather 

 inquiry ever before undertaken promised a richer harvest of meteoro- 

 logical lore than that which rigidly follows up its simtdtaueous obser- 



