March ii, 1886] 



NA rURE 



445 



They had sufficiently established the general practicability 

 of the attempt, and they had obtained an actual speed 

 through the air of about 6 miles an hour, and it was 

 easy to argue that by suitable provisions this might be 

 increased to lo, 20, or perhaps even 30 miles an hour. 



Meantiine the French, who had no insular prejudices 

 to restrain them, continued their experiments. ^I. Gaston 

 Tissandier, an eminent man of science as well as a skilled 

 aeronaut, conceived the possibility of applying electrical 

 power for balloon propulsion ; he exhibited a working 

 model at the Paris Electrical E.xhibition of 1881, and 

 afterwards made, at his own expense, a large balloon, 

 with which in 18S3 he obtained a velocity of 9 miles an 

 hour. But the French military authorities (wiser in their 

 generation than ours) here stepped in, and, with their 

 greater resources, carried the trials still further. They 

 commissioned two of their engineer officers, Messrs. 

 Renard and Krebs, to construct a balloon with which the 

 problem might be thoroughly worked out, and the result 

 is now given. The experiment has been a perfect suc- 

 cess : an independent velocity through the air has been 

 attained of upwards of 13 miles an hour; the bal- 

 loon has been managed, steered, and guided with the 

 greatest ease, and it has, in defiance of the wind, been 

 made to return to its starting-point, the test proposed by 

 Col. Burnaby. 



But the most valuable part of the communication to 

 the Academy of Sciences has been the investigation of 

 the bearing of the experiments on the scientific conditions 

 of the problem. There were two points especially which, 

 from the want of actual experience, had in former calcu- 

 lations to be estimated by analogy from water navigation : 

 the resistance which a balloon would encounter at dif- 

 ferent speeds in its passage through the air, and the 

 efficiency of the screw propeller in overcoming this re- 

 sistance. 



First, as to the resistance. M. de Lome estimated this 

 by the midship section, but in a vessel much elong- 

 ated the length has also to be taken into account. Prof. 

 Rankine has given a rule for ships according to the 

 wetted surface, and also another dependent on the dis- 

 placement. Adapting these to air, and miking certain 

 additions which M. de Lome estimated as special to the 

 balloon, I obtained for the resistance in lbs., the diameter 

 and length being in feet, and the velocity in feet per 

 second — 



By the skin friction R = o'oooo^jjdh' \ 

 By the displacement R = o<xx)oSS6{d'/)hr. 



Now, taking the proportion of MM. Renard and Krebs's 

 balloon at / = 6if, these equations become — 

 R = o'ooo2S6</"-j'=, 

 and A' = o'ooo292rf-j'=. 



The result of the latest French experiments is, when put 

 in English measures — 



R = o'ooo^zoii'T^. 



This is a little higher than the estimation by the former 

 methods, but it corresponds sufficiently well to give 

 confidence in the general mode of inquiry. 



Secondly, as to the efficiency of the screw propeller. 

 This has been often investigated for water navigation, and 

 it may be said that an efficiency of 70 per cent, is 

 fairly borne out by experience. Mi\L Renard and Krebs 

 obtain for their screw an efficiency of only about 50 per 

 cent. 



It is, I should think, highly probable that by further 

 experience both these elements may be considerably 

 amended ; but even taking the facts as they are, they 

 show the attainment of consid;;ably higher speeds to be 

 perfectly practicable. A balloon of 50 feet diameter, 

 for example, would carry power sufficient to give a speed 

 of upwards of 20 miles an hour, and still leave a con- 

 siderable buoyancy disposable. 



At any rate, let us hope that we may have no more 

 quasi-scientific declarations of the impossibility of propel- 

 ling and guiding balloons, and no more sneers at those who 

 attempt to solve the problem. The capabilities of aerial 

 locomotion of this kind must (as I have fully shown else- 

 where) be necessarily limited, but its utility in certain 

 situations would be incontrovertible. The President of 

 the Institution of Civil Engineers, Sir F. Bramwell, 

 speaking in January 1885, said : — 



" There may undoubtedly be particular circumstances in 

 which this mode of locomotion would he useful, such, for ex- 

 ample, as the exploration of new countries, or as the present 

 Egyptian campaign. I strongly suspect that if our lively neigh- 

 bour;, instead of ourselves, had been invading the .Soudan, they 

 would lon^^ before this have had a dirigible balloon looking 

 down into Khartoum." 



.And we have now a curious comment on his words, as 

 we know that at that very time there was, lying in its shed 

 near Paris, a balloon which, though perhaps it could not 

 have saved Gordon, might certainly have saved poor Bur- 

 naby, and otherwise have been of incalculable benefit to 

 our military operations. \ViLLi.\.M Pole 



MEDICAL STUDY IN OXFORD 



STATUTES for the regulation of the qualifications of 

 Candidates for Degrees in Medicine and Surgery, 

 and for creating a Faculty of Medicine in the University 

 of Oxford, have after prolonged discussions been approved 

 by Congregation in their definitive form. The Statute 

 which places the medical studies of the LJniversity under 

 the control of the new Board of the Faculty of Medi- 

 cine recently received the final sanction of Convocation, 

 and the other statutes will soon lollow. The interest 

 which these Statutes have excited could certainly not be 

 attributed to the radical nature of the changes which they 

 will initiate. It must be rather due to the circumstance 

 that the establishment of the new Faculty is regarded as 

 an indication that Oxford, which has hitherto stood alone 

 as the only University in the United Kingdom w-hich has 

 no mdeical students, and in which there is no organisa- 

 tion for medical instruction, now intends to undertake 

 this function. 



It is well known that the Oxford Medical Degree is 

 one of the most coveted professional distinctions, but 

 it does not, like that of Cambridge or Edinburgh, mean 

 that the possessor of it has been trained either in science 

 or in medicine at Oxford. In future there is reason to 

 hope that it will be otherwise — that the University will 

 no longer confine itself to the giving of degrees, but will 

 teach all those branches of medical knowledge which 

 come within the range of University studies. 



Chemistry, Iiuman anatomy, and physiology, are the 

 three subjects which constitute the scientific foundation 

 of medical education, the last-mentioned being itself 

 founded on the other two. For the instruction of medical 

 students in human anatomy, the University has lately 

 imported from Edinburgh an accomplished and ex- 

 perienced teacher. Dr. Arthur Thomson, who has 

 already as many pupils as he can find room for ; and 

 the completion of the new laboratory has rendered 

 possible the development of practical work in physiology. 

 But the mere providing of the means of instruction in 

 these subjects is insufficient, unless the lectures and 

 laboratory work are so systeniatised as to enable the 

 student to learn all that he needs to learn within the 

 limited time at his disposal, and at the same time each 

 branch of teaching is sufficiently specialised to adapt it 

 to his requirements. 



The bearing of the new statutes on medical education 

 in the University can be best understood in relation 

 to the course of scientific training which an intending 

 student of medicine will, if they are passed, be able to 

 follow. Hitherto the Oxford graduate who has obtained 



