January 30, 1885. 



SCIENCE, 



91 



on the Isthmus of Panama was 011I3* one half- 

 inch, and the elevation of the railroad less than 

 one-twentieth of an inch. Again : the moun- 

 tain of Santa Marta, near Cartagena, was 

 17,000 feet, or nearly three inches in height; 

 but the whole gave relative heights which could 

 have been shown in no other way. 



J. R. Bartlett. 



I*. S. hydrographic office, Jan. 15. 



THE BALLOON IN METEOROLOGY. 



On the afternoon of Jan. 19 the first bal- 

 loon ascent ever made in this county solely 

 in the interest of meteorology took place at 

 Philadelphia. As the beginning of a series to 

 be carried out strictly for scientific purposes, it 

 was an event of no small importance. Gen. 

 Hazen, chief signal-officer, U.S.A., recognizing 

 the importance and value of a more complete 

 knowledge of the upper atmosphere, entered 

 into a contract some time ago with the well- 

 known aeronaut, Mr. S. A. King, for a num- 

 ber of ' trips to the clouds,' an ascent to be 

 made at any time on eight hours' notice. 



Although the first balloon excursion for 

 strictly scientific purposes made in America, 

 this was by no means the first on record. 

 Naturally, xery soon after the invention of the 

 balloon, attempts were made to utilize it in me- 

 teorological investigations. Doubtless, the first 

 ascents having this end in view were made by 

 Mr. Robinson, from St. Petersburg, at the 

 command of the emperor of Russia, in 1803 

 and 1804 ; but it does not appear that airy im- 

 portant results came from them. On Aug. 31, 

 1804, Gay-Lussac and Biot made an ascent, 

 reaching a height of thirteen thousand feet ; 

 and meteorological observations were com- 

 menced after an elevation of seven thousand 

 feet had been passed. On Sept. 15 of the 

 same 3 T ear, Gay-Lussac reached a height of 

 twent} T -three thousand feet, making a series of 

 most important observations, and bringing air 

 down from that height, which, on being ana- 

 lyzed , was found to have the same constitution 

 as that at the surface. 



Not much seems to have been done from 

 that time until 1843, when the British associa- 

 tion for the advancement of science appointed 

 a committee and voted a sum of money for 

 the purpose of experimenting with captive bal- 

 loons. Although the work was continued under 

 several committees, it was not very successful, 

 owing, doubtless, to a lack of skill in the man- 

 agement of captive balloons. In 1850 Messrs. 

 Bixio and Barral made ascents in France for the 



purpose of meteorological study, in which it was 

 planned to ascend to heights as great as forty 

 thousand feet. They did not succeed, however, 

 in reaching greater elevations than had been 

 attained before, but obtained results verifying 

 in the main those of Gay-Lussac. On one of 

 these excursions an elevation of twenty-three 

 thousand feet was reached ; and, in addition to 

 the meteorological work, interesting observa- 

 tions were made on polarization and other opti- 

 cal phenomena. 



A series of very important ascents was 

 made by Mr. Welsh of the Kew observatory 

 in August, October, and November of 1852. in 

 which heights valuing from twelve thousand 

 feet to twent3^-three thousand feet were reached. 



A few years later the interest of the British 

 association in the subject was renewed, and 

 culminated in the celebrated series of ascents 

 made by Mr. Glaisher, the first being on July 

 17, 1862. In these ascents the most complete 

 arrangements were made for the stud} T of the 

 plrysics of the higher atmosphere, and they 

 were remarkably successful. 



Since that time, scientific ballooning has 

 been carried on with great success in France 

 by Camille Flammarion, W. De Fonville, and 

 Gaston Tissandier. A complete and extremely 

 interesting histoiy of their work (up to the 

 date of its issue), together with that of 

 Glaisher, is to be found in a volume entitled 

 ' Travels in the air,' by James Glaisher. 



The U. S. signal-service has had this subject 

 under consideration for several years. Pro- 

 fessor Abbe began in 1871 to collect meteoro- 

 logical records made in balloons. In 1872 the 

 records of fifty ascents had been tabulated, 

 studied, and valuable results obtained. In 

 1876 one thousand small balloons were sent 

 with the Polaris expedition, to be used in 

 determining the height of the clouds ; but, 

 owing to an unfortunate accident, they could 

 not be utilized. At various times the chief 

 signal-officer has sent observers on balloon 

 excursions which were made for purposes other 

 than scientific. 



The considerable certaint}^ with which the 

 movement of a storm can now be predicted 

 renders it possible and desirable to make s}'s- 

 tematic use of the balloon in the study of 

 unusual atmospheric conditions, and the series 

 of ascents just begun is planned with that end 

 in view. Among other things, it is desired to 

 determine the difference in the temperature 

 gradient in well-defined ' high ' and well-defined 

 ' low ' pressures. For this purpose it is neces- 

 sary to foretell the arrival of a particular 

 atmospheric condition at Philadelphia, from 



