THE INTERNATIONAL WEATHER-SERVICE. 297 



arresting and consuming those countless meteoric stones, showered 

 upon us from stellar space, before they can penetrate to the lower 

 aerial strata. For us, at least, in respect to this sublunary scene, it is 

 of engrossing interest, as that all-pervading organism Avhich 



"Lives through all life, extends through all extent, 

 Spreads undivided, operates unspent." 



In the technical execution of this purely pioneer work, the first step 

 was the preparation of a daily graphic and synoptic chart exhibiting 

 all the weather observations taken simultaneously in the northern 

 hemisphere. On the 1st of July, 1878, the Signal-Office at Washing- 

 ton began the regular publication of a daily international loeather- 

 map, charted daily and issued daily, each chart being based upon the 

 data appearing in the " International Bulletin of Simultaneous Re- 

 ports " of similar date. The daily issue of a weather-chart of this kind 

 and scope is without a precedent in history. It illustrates the cooper- 

 ation, for a single purpose, of the civilized powers of the globe north 

 of the equator, and brings the atmospheric phenomena over the whole 

 field of the research, and in their true relations to each other, within 

 the easy comprehension of the student's eye. (See frontispiece.) As 

 these charts in successive order are spread out day after day, the 

 investigator has before him a vivid panorama of the physical forces 

 in pictured action, so that he can readily trace their mutual depen- 

 dence and interaction in the normal working of the ponderous, yet 

 beautiful, atmospheric machinery. 



The history of progress in the discovery of physical phenomena and 

 their laws is intimately connected with the introduction of technical 

 contrivances so simple that at first they attract little notice. After 

 the invention of the mariner's compass, and the astrolabe, nothing 

 perhaps that was done for geographical science gave it such an im- 

 pulse as the chart introduced in 1556 by Gerard Mercator, by which 

 the earth's entire surface was presented in a single picture to the geog- 

 rapher's eye, and by which (the degrees of latitude and longitude at 

 all places bearing to each other the same relations they bear on the 

 sphere itself) the navigator could readily steer his ship in straight lines. 

 This simplest of contrivances became, in a word, an invaluable instru- 

 ment of maritime exploration and discovery, the present and almost 

 exclusive employment of which by mariners of all nations, as the chart 

 for the ocean, has brought the name of Mercator down to this day in 

 honored remembrance. Not to dwell upon the charts of Paolo Tosca- 

 nelli in the fifteenth, and of Martin Behaim in the sixteenth century, so 

 justly celebrated — the former as guiding Columbus on his great west- 

 ward voyage, and the latter as blazing Magellan's perilous way toward 

 the southern shore of South America, to circumnavigate the globe — we 

 may well say, " Accurate maps are the basis of all inquiry conducted on 

 scientific principles." The " International Weather-Map of Simulta- 



