Oct. 17, 1878] 



NATURE 



039 



SCIENTIFIC BALLOONING 



Hist aire de mcs Ascensions. Recit de Vingt-quatre 

 Voyages airiens (1868- 1878) predde de simples Notions 

 sur les Ballons ct la Navigation aericnne. Par Gaston 

 Tissandier. Illustre de nombreux dessins par Albert 

 Tissandier. (Paris : Dreyfous, 1878.) 



M TISSANDIER has just published a handsome 

 and well-illustrated volume, giving a history 

 of his twenty-four ascents with an account of their 

 scientific results, which are of very considerable im- 

 portance. M. Tissandier is one of the most scientific 

 of modern aeronauts, and has, by his ascents, made 

 important additions to our knowledge of atmospheric 

 phenomena. The work to which we refer ought to 

 interest many readers ; it is not only full of adventures, 

 of ''hairbreadth 'scapes," of humorous incidents, and 

 beautiful descriptions of atmospheric scenes, which ought 

 to prove attractive to the general reader, but contains, 

 besides, a large amount of data of great_importance in 

 connection with the physics of the air. 



Aeronautics, M. Tissandier tells us, may be divided 

 into five distinct branches: — i. The balloon itself. 2. 

 Meteorological aerostation, in the scientific exploration 

 and study of the atmosphere. 3. IVIilitary ballooning, 

 captive aerostats, military reconnaissances, the aerial 

 post. 4. Direction of aerostats and aerial navigation. 

 5. "Aviation," or mechanical flight, the principle of 

 which has been designated under the phase "heavier 

 than air." In the first part of M. Tissandier *s work will 

 be found a resume of the principal events in the history 

 of aeronautics, from the first rude attempts down to the 

 magnificent captive balloon of M. Gififard, which has 

 excited so much attention during the Paris Exhibition. 

 The author gives an account of the present state of aerial 

 navigation, and shows what may be expected in the 

 future, judging from facts submitted to the test of scien- 

 tific reasoning. 



The second part of M. Tissandier's work contains an 

 extremely interesting and scientifically valuable account 

 of twenty-four aerial voyages made by himself. It is 

 about ten years since M. Tissandier made his first ascent, 

 and the greater number of his ascents have been made 

 in company with his brother, M, Albert Tissandier, who 

 by the aid of his pencil has recorded the ever new, 

 always interesting, and often incomparable spectacles 

 which the atmosphere opens to the eye of the explorer. 

 Many of his sketches are of great meteorological, as well 

 as artistic, value. In the second part of the work an 

 explanatory diagram indicates exactly the route taken 

 during each journey, the altitude attained, the nature and 

 situation of the clouds, the direction of the currents, their 

 temperature and the atmospheric circumstances connected 

 with them. Numerous wood engravings, from drawings 

 by M. Albert Tissandier, represent the marvellous spec- 

 tacles observed, the effects of clouds, sunsets, and the 

 various optical phenomena witnessed during the journeys 

 described. Indeed, the work is so luxuriantly got up, 

 and so profusely illustrated, that we are bound to infer 

 either that M. Tissandier's publisher is unusually gene- 

 rous or that France must possess a considerable reading 

 public of more than average intelligence. 



The work contains a detailed description of the struc- 



ture of M. Gififard's monster captive, to the understanding 

 of which the many well-executed illustrations are a great 

 help. An appendix gives the interesting experiments as 

 to carbonic acid in the air made in the Zenith by MM. 

 Tissandier and Mangon, and a detailed description of 

 Giftard's new apparatus for the preparation of hydrogen 

 in large quantities. 



In a recent lecture at the Sorbonne M. Tissandier 

 endeavoured to point out some of the important services 

 which aeronautics might be made to render to science. 

 A purely theoretical science has necessarily few admirers. 

 It should not be so, however, with the investigation of 

 aerial phenomena. This important department of the 

 physics of the globe is not only useful to the sailors 

 and agriculturists of all nations ; it is also of great 

 service in public hygiene. But in order that meteoro- 

 logy, quite a modern science, might be instituted, there 

 should be no doubt of the materiality of the air, thanks 

 to the conceptions of the Galileos, Torricellis, and 

 Pascals. The Meteorological Society of the Palatinate 

 was only founded in 1781 ; only then were registrations 

 of atmospheric variations begun. The invention of the 

 telegraph soon permitted simultaneous observations to be 

 made, and centralised and led to the hope that prevision 

 of the weather would cease to be an unrealisable chimera, 

 M. Tissandier points out how serviceable to oceanic and 

 river navigation are the warnings transmitted by the In- 

 ternational Meteorological Service to the principal mari- 

 time stations. The organisation of this service enables 

 us to follow effectively the progress of centres of depres- 

 sion, to discover and announce the general direction of 

 winds, to figure their spirals across space, to establish 

 the curves of the isobaric lines or lines of equal pressure ; 

 better still, to prevent, by means of the telegraph, more 

 rapid even than the tempest, a great number of ship- 

 wrecks and accidents on coasts. 



To discover the real cause of the movements of the air, 

 of cyclones, of the mode of formation, of the direction 

 and variations of the rate of Avinds, it is necessary, to use 

 the expression of Biot, " prendre la meteorologie par en 

 haut," i.e., to seek in the elevated regions of the atmo- 

 sphere the explanation of the phenomena which occur at 

 the bottom of the aerial ocean where human destinies are 

 accomplished. In fact, " it is in the high regions of the 

 air that meteors are formed, rain, snow, hail ; it is there 

 that the lightning traces its furrow, and the thunder rolls ; 

 it is there that the aurora borealis displays its plume of 

 light, and that the aerolite shines forth and bursts. There 

 are the upper currents which chariot the clouds. It is 

 to these elevated regions that the science of meteorology 

 ought to be directed." 



The observer has the choice between two distinct 

 methods of exploration. He may ascend the mountains 

 or mount in a balloon. No doubt the former process 

 appears at first most secure, but it is seen that the second 

 presents, practically and theoretically, superior advan- 

 tages, offers most security, and is attended with better 

 results. It suffices to recall the obstacles encountered, 

 the dangers incurred by a tourist guide, the obscure 

 protagonist of the memorable labours of De Saussure, 

 the energetic Jacques Balmat. If he was the first, in 

 August, 1786, to strike his iron-shod staff on the crest of 

 the giant of the Alps, it was only after many fruitful 



