May 5, 1922] 



SCIENCE 



495 



requirements of the loud speaking telephones had 

 made the problem inherently insoluble until means 

 had been developed for producing telephone lines 

 with very uniform transmitting characteristics and 

 until amplifying devices of great power, uni- 

 formity and freedom from inherent distortion 

 production -had been developed. 



The physical examination of hearing and 

 binaural aids for the deaf : E. L. Wegel, Western 

 Electric Company, New York City. The function 

 of the auditory sense is to detect sounds of dif- 

 ferent wave shapes, the ratio of the pressure on 

 the ear drum varying over a range of 

 1 : 1,000,000. It must also differentiate between 

 sounds so nearly alike that no existing physical 

 apparatus is capable of separating them. Binaural 

 audition adds a sense of orientation and discrim- 

 ination together with a more uniform sensitivity 

 for sounds approaching from different directions. 

 A binaural set for aiding the hard-of -hearing was 

 exhibited. An abnormal auditory sense may be 

 regarded as one lacking to a greater or less de- 

 gree in (1) range of sensation (frequency or 

 intensity), (2) quality of sensation in various 

 regions of the range, (3) binaural sense. Methods 

 have been studied for exploring the outstanding 

 elements of these functions. A new audiometer 

 for measurement of hearing was shown. 



The relative sensitivity of the ear at different 

 levels of loudness: Dr. Donald Mackenzie, 

 Western Electric Company. Up to the present 

 time there has been no satisfactory technique for 

 loudness comparisons of different tones. In this 

 paper a description is given of an alternation 

 phonometer which makes it an easy matter to ad- 

 just to equal loudness two tones of different 

 pitches. With this instrument a determination 

 has been made of the relative sensitivity of normal 

 ears of both men and women, over the pitch range 

 from bass G to C5, at sound intensities midway 

 between the faintest audible and the painfully 

 loud. It is found that the sound energy necessary 

 to produce a given loudness is smaller the higher 

 the pitch, at least within the range examined. 

 Different ears agree more closely at these intensi- 

 ties than at the least audible, and no difference 

 is detectible between men and women. Inter- 

 pretation of the results shows them to be in har- 

 mony with Fechner's law, according to which the 

 difference between the sensations due to two lights 

 of the same color or two tones of the same pitch 

 is proportional to the ratio of intensities of the 

 lights or sounds causing the sensations. This 

 simple law holds only at moderate intensities. 

 Phonometric comparisons by a small number of 



observers were made at intensities from very faint 

 to very loud. It appears that any one ear varies 

 from day to day, but these variations are most 

 noticeable at the extremes of loudness. The re- 

 sults taken all together strongly suggest that, on 

 the average, the relative sensitivity of the ear to 

 different musical notes is practically the same 

 whether the sounds are loud or faint. 



Recent progress in aeronautics : Peofessoe J. S. 

 Ames, The Johns Hopkins University. 



Coefficients of slip and the reflection of mole- 

 cules: De. E. a. Millikan, jSTorman Bridge Lab- 

 oratory of Physics, Pasadena. This paper con- 

 tains a presentation of the theoretical relations 

 between the coefficient of slip and the law of 

 reflection of gas molecules from the surfaces of 

 solids and liquids. It presents, also new experi- 

 mental data taken by the author and his pupils 

 which completely check the correctness of this 

 theory. It gives for the first time the exact ratio 

 between the number of impinging molecules which 

 are specularly reflected in the case of a given gas 

 from given liquid and solid surfaces, and the 

 number which are diffusely reflected. The most 

 interesting facts brought to light by the investi- 

 gation are, first, that this ratio is different for 

 different kinds of molecules when the nature of 

 the surface remains constant, and, second, that 

 there is a larger coefficient of slip between oiled 

 surfaces and gases than between the same gases 

 and ordinary unoiled surfaces of metal or glass. 



Origin of penetrating radiations of the upper 

 air: De. K. A. Millikan, Norman Bridge Lab- 

 oratory of Physics, Pasadena. It is of intense 

 interest to know whether the penetrating radia- 

 tions which have been heretofore studied up to 

 altitudes of 9,000 meters are of cosmic or of 

 terrestrial origin. Pre-war observations made in 

 manned balloons in Germany gave indications that 

 they were of cosmic origin. Observations pub- 

 lished last year from the University of California 

 were in opposition to this view. Indeed, the Cali- 

 fornia observers attributed the increase in the rate 

 of discharge of the electroscopes with increasing 

 height, as found in Germany, to the effects of 

 temperature upon the electrical conductivity of 

 the supports of the gold leaves in the electro- 

 scopes. The observers at the California Institute 

 of Technology have definitely proved that the tem- 

 perature effects upon the supports when the ex- 

 periments are properly performed are practically 

 negligible. They are now making balloon flights 

 in which self-recording instruments are sent up to 

 the very top of the atmosphere, that is, to a point 

 at which only one sixteenth of the atmosphere is 



