xTilY ° F SC,ENCES1 BIOGRAPHY 15 



his eminence as an authority on acoustics, received the remarkable compliment of being put 

 on a committee to study the physical conditions of the House of Commons. H 



The years 1914-15 and 1915-16 were for him a period of comparative quiet, spent in teach- 

 ing and acoustic investigations, doubtless with much attention to plans for the acoustic labora- 

 tory to which reference has already been made. But for the war, he would probably have 

 had before Mm a long career of growing usefulness and fame, and would have lived to a vigor- 

 ous old age according to the habit of his ancestors. But from that fiery furnace into which 

 other men were drawn by millions he could not hold himself back. He would have felt recreant 

 if he had escaped unscathed. 



Going to France in 1916, with the intention of giving a course of lectures at the Sorbonne 

 in the fall, he engaged during the summer in relief work that took him to Switzerland. Over- 

 taxed in strength, he was attacked during the fall by a malady that compelled the postpone- 

 ment of his lectures and nearly ended his life at once. When he was able to be moved, he went 

 from Paris back to Switzerland, this time as a patient; but he gained strength, studying French 

 constantly meanwhile, and in the spring of 1917 gave his lectures, on architectural acoustics* 

 at the Sorbonne. 



Such notes of these lectures as are available contain little that had not already been printed 

 in English, but a few paragraphs taken from them by Dr. Theodore Lyman for use in the Col- 

 lected Papers may well be given here in illustration of what Sabine considered to be, in a word, 

 his contribution to acoustics, the consideration of" boundary conditions": 



In no other domain have physicists disregarded the conditions introduced by the surrounding materials, 

 but in acoustics these do not seem to have received the least attention. If measurements are made in the open 

 air, over a lawn, as was done by Lord R&yleigh in certain experiments, is due consideration given to the fact 

 that the surface has an absorbing power for sound of from 40 to 60 per cent? Or, if inside a building, as in 

 Wien's similar experiments, is allowance made for the fact that the walls reflect from 93 to 98 per cent of the 

 sound? We need not be surprised if the results of such experiments differ from one another by a factor of more 

 than a hundred. 



It would be no more absurd to carry out photometric measurements in a room where the walls, ceiUng, and 

 even the floor and tables consisted of highly polished mirrors, than to make measurements on the intensity, or 

 on the quantitative analysis of sound, under the conditions in which such experiments have almost invariably 

 been executed. It is not astonishing that we have been discouraged by the results, and that we may have 

 despaired of seeing acoustics occupy the position to which it rightly belongs among the exact sciences. 



The length of the waves of light is so small compared with the dimensions of a photometer that we do not 

 need to concern ourselves with the phenomena of interference while measuring the intensity of light. In the 

 case of sound, however, it must be quite a different matter. 



In order to show this in a definite manner, I have measured the intensity of the sound in all parts of a 

 certain laboratory room. For simplicity, a symmetrical room was selected, and the source, giving a very pure 

 tone, was placed in the center. It was found that, near the source, even at the source itself, the intensity was 

 in reality less than at a distance of five feet from the source. And yet the clever experimenter, Wien, and the 

 no less skillful psychologists, Wundt and Munsterberg, have assumed under similar conditions the law of varia- 

 tion of intensity with the inverse square of the distance. It makes one wonder how they were able to draw 

 any conclusions from their measurements. 



The following extract from a letter written to me August 15, 1917, gives Sabine's own 

 comments on these lectures and some indication of the work in which he engaged when they 

 were ended: 



The lectures at the Sorbonne then began quietly. There were twenty-five in the audience the first day, 

 and this number rose to fifty — but lecturing at the Sorbonne while the world is being transformed into a totally 

 different institution, and life such as is left of it is sobered for years to corner — lecturing at the Sorbonne seems a 

 thing apart. I was also asked to lecture at the Ecole des Beaux Arts, to give a public lecture, and to lecture 

 before the Society of Architects. The latter was so kind as to give me a medal as souvenir of the occasion; 

 they find the time and the heart to do things nicely in France, nicely and kindly even in the midst of death. 



The lectures had hardly stopped when I was asked to help in the Information Bureau of the United States 

 Navy here in Paris on the submarine question — a week later by the French Bureau des Inventions on submarine 

 and aeroplane questions; I am also definitely on the staff of the Bureau of Research of the Air Service of the 

 American Expeditionary Force — a long title — and I have just received a request from the British Munitions 

 Inventions Bureau to come over to England for consultation on some problems in acoustics. 



" He told me gleefully that he thereupon asked to be admitted to the floor of the House during a session, for the purpose of making acoustic 

 observations, and was so admitted, greatly to the damage of that formidable English institution, precedent. 



