Jan. 13, 1887] 



NA TURE 



259 



Bokhara a large tract of land on the banks of the Amu-daria, 

 near the Chardjui station of the Transcaspian Railway, for the 

 cultivation of cotton. In the Transcaspian there seems to be a 

 great district suitable f.r cotton-growing, and there is a general 

 opinion among the commercial classes of Russia that the develop- 

 ment of this industry ought to be steadily encouraged by the 

 Government. 



The BoUettino of the Italian Geographical Society for Novem- 

 ber contains an account of a second expedition by Signor E. 

 Modigliani to Nias, which has proved much more successful 

 than his first visit to that island, reported in Nature, Novem- 

 ber 16, 1886, p. 60. His primaiy object was to discover and 

 ascend the Mount Matsua, 600 metres high, seen by Von Rosen- 

 berg from the west coast, and figured on his map as the culmin- 

 ating point of the island. But, although no trace could be 

 found of this mountain, the hitherto unexplored south-western 

 district was traversed from Serombu on the west to Lagundi 

 Bay on the south coast. This district was carefully surveyed, 

 and the explorer succeeded in making rich zoological, botanical, 

 and ethnological collections, most of which have been forwarded 

 to the Natural History Museum of Genoa. They include no 

 less than twenty-six human skulls (fifteen of which were obtained 

 at Hili Horo in exchange for a rille), about 120 birds, 2000 

 butterflies, 1500 other insects, monkeys, fishes, reptiles, and 

 plants. The journey was made during the summer of 18S6, 

 Signor Modigliani's last communication being dated August 10, 

 and forwarded to Europe from Gunun^ Sitoli, in the north of 

 Nias, where he was then stationed with the intention of con- 

 tinuing his scientific researches in the island. 



On Tuesday evening last Captain Cameron delivered at the 

 London Institution a lecture on " Urua : its People, Government, 

 and Religion." In closing his lecture Captain Cameron said 

 that Urua would sfiortly come into great prominence, for 

 lately some of the officers of the Congo Free State had followed 

 the river due east, across the great bend of the Congo, showing 

 that it was a navigable river, and that if followed up it would lead 

 to Kasongo's capital. They were frequently hearing of the 

 London Missionary Society's agents pushing up the new great 

 tributary of the Congo on the south, so there could be little 

 doubt that in a short time the Somami would be followed up to 

 Urua, and that traders, missionaries, and others would soon come 

 into the great kingdom of Urua, wliere there was a great work 

 before them. However, they would have to bear in mind that 

 they would not have to do with a little chief ruling over 200 or 

 300 natives, but with a powerful monarch who ruled absolutely 

 over his people, and who would allow of no agreement which had 

 not been approved by him. It was to be hoped tliat, as Stanley 

 had been successful before, he might be successful in his ex- 

 pedition for the relief of Emin Pasha, and also that those who 

 went into Urua would bring civilisation and peace, and be able 

 to do av-^ay with the horrors of the slave trade which obtained 

 there owing to the Portuguese and the Arabs. Urua was rich in 

 many kinds of minerals and other products, and the people were 

 a fine race. When the Europeans came into con-tant contact 

 with them, if they were wisely managed, thei'e would be a great 

 future for them. 



WAR AND BALLOONING 

 "T^HE object which stimulated the practical invention of the 

 balloon was its use in war. I say practical invention, 

 because in theory' the balloon was invented before the experi- 

 ment of Montgolfier. Theory is ever the soil of practice. The 

 idea of the balloon has its starting-point in the principle of the 

 pressure of fluids elucidated by Archimedes, of Syracuse, 200 

 years before the Christian era. The discovery cf hydrogen gas 

 by Mr. Henry Cavendish, in 1760, led Joseph Black, the Pro- 

 fessor of Chemistry at the University of Edinburgh, to suggest 

 in one of his lectures that a weight might be lifted from the 

 ground by attaching to it a sphere of hydrogen gas. A fruitful 

 idea once expressed is rarely lost, however casual its first ex- 

 pression. Some years later, Tiberius Cavallo, an Italian mer- 

 chant, remembered the remark of Dr. Black, and, in 1782, 

 tested its truth by experiment. He first manufactured some 

 paper bags, which he filled with hydrogen gas : to his disa j- 

 pointment, the subtle gas escaped through the pores of the 

 paper. He then collected the gas in soapy water, and the bubble 



of gas ascended. A soap-bubble filled with hydrogen was 

 therefore the first balloon. The experiment seems to have been 

 repeated by Cavallo at one of the meetings of the Royal Society, 

 and described in the Transactions of that Society ; but neither 

 Cavallo nor his colleague pursued the experiment further, and 

 there was still to be foimd the peculiar kind of energy that 

 would transform the laboratory experiment into a practical 

 reaUty. Books are indeed the carriers of thought. It is pro- 

 bably due to a work of Priestley, in which were described those 

 discoveries of Cavallo, and which was translated into French, 

 that Montgolfier, the paper-maker of Annonay, was fired to 

 perform an experiment that is historical. He, as most of you 

 know, filled a paper bag with heated air, the consequence being 

 that the bag rose to the ceiling of the room. Montgolfier was 

 not content with such trifling eliforts : a patriotic motive stimu- 

 lated him to attain greater results — the desire to make the in- 

 vention of use to France in her wars ; and the paper bag of 

 40 cubic feet capacity was succeeded by one of 680 cubic feet ; 

 this, again, by one of 23,000 cubic feet. Montgolfier seemed 

 on the high-road to a brilliant success. There was, however, 

 another brain actively employed in eclipsing the fame of Mont- 

 golfier— that of Charles, the Parisian, who realised that heated 

 air would never become a satisfactory method of filling bal- 

 loons, heated air being three-fourths the weight of the air at 

 the ordinary temperature. He therefore took up the experi- 

 ments with hydrogen gas uhere Cavallo had left off. Hydrogen 

 gas being thirteen times lighter than air, its superiority in filling 

 balloons was, to his mind, indisputable. He succeeded in 

 making a material gas-proof, and consequently produced the 

 first practical gas- balloon. 



From the efforts of Montgolfier and Charles began the his- 

 tory of ballooning. I do not propose to discuss its general 

 history this evening, with its startling incidents of adventure, 

 nor to enumerate the good service the balloon has rendered to 

 science in the hands of such men as Benedict de Saussure, 

 Robertson, and Glaisher, but to make a few remarks upon its 

 use as an adjunct of war. 



By many persons, those who advocate its use in war are looked 

 upon as enthu-iasts. With many persons, an enthusiast is 

 synonymous with a fanatic. Now, I agree that enthusiasm is 

 sometimes expended on improper subject-matter — on wild in- 

 coherent schemes ; but give enthusiasm proper subject-matter, 

 truth, and coherency, and it becomes a noble thing ; it is, in 

 fact, the life-blood of science and art. It is, in other words, 

 earnestness of purpose. I think the use of balloons in war is 

 worthy of this earnestness of purpose. 



I have to bring before your notice this evening, in particular, 

 a somewhat new departure in balloon^, in which electricity is 

 so combined with a captive ballom as to render it valuable for 

 signalling- purposes. Before I describe this special use for bal- 

 loons in war, which I have had the honour of introducing to the 

 English Government, and for which I hold patents in the prin- 

 cipal foreign countries, I will say a few words concerning the 

 general use of balloons in time of war. 



The way in which balloons hive been chiefly utilised in war 

 is for taking observations of the enemy. In such cases the 

 balloons are captive. As early as 1793 the French Government 

 adopted the use of captive balloons. Such balloons were em- 

 ployed with great success in those wars which the Fr-ench 

 Goverment carried on soon after the French Revolution. There 

 was a regular company formed, called " Aerostiers," and it seems 

 tome that more practical work with captive balloons was done 

 in actual war at this period than has been accomplished since. 

 It was Napoleon who put an end to their career of usefulness in 

 France, and who closed the Aeronautical School at Meudon. 



It is this use of captive balloons for observations that has 

 lately been revived by the English Government, and experiments 

 are frequently carried on at Chatham under a Committee of the 

 Royal Engineers. Notably amongst those who have been pro- 

 minent in the revival of balloons for war purposes we may men- 

 tion the names of Major Templer, Major Elsdale, and Lieut. 

 Mackenzie, and the country, I think, has reason to thank these 

 officers for the really good work they have done with the means 

 at their disposal. At the Inventions Exhi oition there was an 

 exhibit of balloons in the War Department. Perhaps the more 

 important feature of that exhibit was a balloon made of gold- 

 beater-skin, such as was used in the war in Egypt. Gold- 

 beater-..kin is an admirable substance for forming balloons, on 

 account of its lightness and capacity of holding gas. 



The free balloon has its use in war as well as the captive one. 



