September 19, 1890.] 



SCIENCE. 



159 



sight to promise a very important advance in the power of artil- 

 lery. The practical difBculties attending the utilization of these 

 results are, however, sufficiently formidable to place, at any rate 

 at present, comparatively narrow limits upon our powers of avail- 

 ing ourselves of the advantages in ballistics which they may pre- 

 sent. The strength of the gun-carriages, and the character of the 

 arrangements used for absorbing; the force of recoil of the gun, 

 need considerable modifications; greater strength and perfection 

 of manufacture are imperative in the case of the shells to be used 

 with charges of a propelhng agent, by the firing of which in the 

 gun they aiay be submitted to comparatively very severe concus- 

 sions; the increased friction to which portions of the explosive 

 contents of the shell are exposed by the more violent setting back 

 of the mass may increase the possibility of their accidental ignition 

 before the shell has been projected from the gun ; the increase of 

 concussion to which the fuze in the shell is exposed may give rise 

 to a similar risk consequent upon an increased liability to a failure 

 of the mechanical devices which are applied to prevent the ignit- 

 ing arrangement from being set into action prematurely by the 

 shock of the discliarge; lastly, the circumstance that the rate of 

 burning of the time-fuze which determines the efficiency of a 

 projected shrapnel shell is materially altered by an increase in the 

 velocity of flight of the shell, also presents a source of difficulty. 



One of the first uses for purposes of warfare, to which it was 

 attempted to apply gun-cotton, was as a charge for shells. 



The author next again refers to the French melinite, and states 

 that, although the secret of its composition vs-as well kept, it soon 

 transpired that the French authorities were purchasing large 

 quantities of picric acid ; and this led to the inference that this sub- 

 stance, known to be explosive, was used in the preparation. 



The precise nature of melinite. Sir Frederick continued, appears 

 to be still only known to the French authorities. It is asserted to 

 be a mixture of picric acid with some material imparting to it 

 greater power; but accounts of accidents which have occurred, 

 even quite recently, in the handling of shells charged with that 

 material, appear to show, that, in point of safety or stability, it is 

 decidedly inferior to simple picric acid. Reliable as the latter is 

 in this respect, its employment is, however, not unattended with 

 the difficulties and risks which have to be encountered in the use, 

 in shells, of other especially violent explosives. Future experience 

 in actual warfare can alone determine decisively the relative 

 value of violent explosive agents, and of the comparatively slow 

 explosive, gunpowder, for use in shells; it is certain, however, 

 that the latter still presents distinct advantages in some directions, 

 and that there is no present prospect of its being more than par- 

 tially superseded as an explosive for shells. Referring to sub- 

 marine mines and locomotive torpedoes, such as the Whitehead 

 and Brennan torpedoes. Sir Frederick stated that progress recently 

 made in the practical development of explosive agents has not re- 

 sulted in the provision of a material which equals wet compressed 

 gun-cotton in cooibiniug with great destructive power the safety 

 to those who have to deal with these weapons. 



The president next proceeded to deal with the question of explo- 

 sions in mines, dwelling at some length on the use of naked lights 

 and safety-lamps, — a subject upon which he is, as is well known, 

 an authority. The petroleum industry next occupied his atten- 

 tion, the following statistics being given of the product of the 

 United States; — 



In 1859, 5,000 barrels (of forty-two American gallons) were pro- 

 duced ; in the following year the production increased to 500,000 

 barrels; while in the next year (1861) it exceeded 2,000,000 barrels, 

 at which figure it remained, with slight fluctuations, until 1865. 

 The supply then continued to increase gradually, until, in 1874, it 

 amounted to nearly 11,000,000 barrels. In 1880 it amounted to 

 over 26,000,000 barrels, and in 1882 it reached 31,000,000. Since 

 then the supply furnished by the United States has fallen some- 

 what, and last year it amounted to 31,500,000 barrels. In addition 

 to the petroleum raised in Pennsylvania, there is now a very large 

 production in the State of Ohio, which is, however, transported by 

 pipe-lines in great quantities to Chicago, for use as liquid fuel in 

 industrial operations. 



The production of crude petroleum in Russia was next referred 

 to in the address. In 1863 the supplies from the Baku district 



amounted to 5,018 tons. They increased to somewhat more than 

 double during the succeeding five years. In 1869 and following 

 three years the production reached about 37,000 tons annually, 

 arid in 1873 it was about 6i,000 tons; three years later, 153,000 tons 

 were produced; and in the following five years there was a steady 

 annual increase, until, in 1883, the production amounted to 677,369 

 tons; in 1884 it considerably exceeded 1,000,000 tons; and last year 

 it was about 3,300,000 tons. The consumption of crude petro- 

 leum as fuel for locomotive purposes has, moreover, now assumed 

 very large proportions in Russia, and many millions of gallons are 

 annually consumed in working the vast system of railways on 

 both sides of the Caspian Sea. 



The imported refined petroleum used in this country in lamps 

 for lighting, heating, and cooking, was exclusively American until 

 within the last few years, but a very large proportion of present 

 supplies comes from Russia. The imports of kerosene into Lon- 

 don and the chief ports of the United Kingdom during ISSft 

 amounted to 1,116,205 barrels of United States oil, and 771,227 

 barrels of Russian oil. During the same period the out-turn of 

 mineral oil for use in lamps by the Scottish Shale Oil Companies 

 probably amounted to about 500,000 barrels. 



The prospects of less-known or less-worked sources of supply in 

 other parts of the world, were next touched upon. The subject 

 led up to some remarks on the discovery and application of 

 natural gas, which, in turn, brought water-gas before the meet- 

 ing. No address delivered to a scientific body is now complete 

 without some reference to technical education, and Sir Frederick 

 naturally devoted a few paragraphs to that subject. The Imperial 

 Institute also could not with decency have been excluded from an 

 important delivei-y by its organizing secretary. Sir Frederick, 

 however, with great moderation, confined himself to a few para- 

 graphs on the subject. The address was of great intei'est, and 

 was listened to by a large audience. It could, of course, have 

 been made doubly instructive had its author dealt with Cordite, 

 among the other explosives upon which he spoke; but this natu- 

 rally would have been a breach of the conventionalities, for which, 

 no doubt. Sir Frederick was sufficiently thankful. 



HEALTH MATTERS. 



Danger in Exercise. 

 The Providence Journal quotes Dr. Patton, chief surgeon of 

 the National Soldiers' Home at Dayton, O., as saying, in an inter- 

 view he had in Pittsburgh, that, of the five thousand soldiers 

 in the Dayton home, " fully 80 per cent are suffering from heart- 

 disease in one form . or another, due to the forced physical exer- 

 tion of the campaigns;" and he made the prediction, according to 

 the Medical and Surgical Reporter, that as large a percentage of 

 the athletes of to-day will be found twenty-five years from now 

 to be victims of heart-disease, resulting from the muscular strains 

 that they force themselves to undergo. As for the likelihood of 

 exercise to prolong life, it may be said, that, according to the sta- 

 tistics of M. de Solaiville, there are more people living in Fi-ance 

 to-day who have passed the age of sixty than there are in Eng- 

 land, the home of athletic sports; and there is probably no nation 

 in Europe more adverse to muscular cultivation for its own sake 

 than the French. Great athletes die young; and a mortality list 

 of Oxford rowing-men, published a few years ago, showed that a 

 comparatively small percentage of them lived out the allotted 

 lifetime. Dr. Jastrow has demonstrated in some very elaborate 

 statistics that men of thought live, on an average, three years and 

 a half longer than men in the ordinary vocations of life. 



Decrease of Tuberculosis in England. 



There is an instructive lesson in the English mortality returns 

 from tuberculosis for the last forty years, says the Medical and 

 Surgical Reporter. In the ten years from 1851 to 1860 the num- 

 ber of deaths from tuberculosis in persons from 15 to 45 years of 

 age amounted to 3,943 in every million; from 1861 to 1870 it had 

 fallen to 3.711 ; from 1871 to 1880 it was 3,194; and from 1881 to 

 1887 it did not exceed 2,666. The decreased rate is more marked 

 in the female than in the male sex. 



