PHYSICS. 349 



wire is heated for the first time after it has left the maker's hands. (Na- 

 ture, April, 1886, xxxii, 582.) 



Mach has iudorsed vou Helmholtz's theory of sonorous sensations, 

 and has attempted to render it more complete by supposing that each 

 fiber of Corti vibrates, not only to its predetermined fundamental note, 

 but also, though more feebly, to the harmonics and even the subliar- 

 monics of this note. From this arises an auxiliary sensation of timbre 

 and a characteristic perception of musical intervals. (Auz. Ak. Wein, 

 1885, 275; J. Phys., May, 1S8G, II, v, 243.) 



Robin has discussed the theory of the gamut and has given a table 

 in which are compared the number of vibrations of the notes of the 

 scale, the logarithms of these, and the lengths of strings giving these 

 notes, for the tempered gamut, the gamut played by musicians, and 

 that in use by physicists. An inspection of the table shows : (1) That 

 the tempered gamut, imposed practically upon all instruments with 

 fixed keys, differs much less from the gamut of the musicians than from 

 that of the physicists; and (2) that the differences between the t^o lat- 

 ter, notable for mi, la, si, and for almost all the altered notes, are esi)ec- 

 ially great for re, sol, and la sharp, reaching nearly a semi-tone. (J. 

 Phys., September, 1886, II, v, 419.) 



Boutet has made an experimental study of the best means of produc- 

 ing pure and constant sounds in tubes, and especially of the influence 

 of the material, of the form, of the diameter, and of the thickness of 

 sonorous orifices. The results are given in the form of tables. (Ann. 

 Chiiu. Phys., November, 1886, VI, ix, 406.) 



Von Lang has suggested the use of the Hipp chrouoscope for the 

 puri)ose of determining the pitch of a tuning-fork. To do this the reg- 

 ulating spring of the chrouoscope is adjusted to ijroduce a note very 

 near in pitch that of the fork. By suitably bowing it, the fork is kept 

 in vibration for several minutes, and the beats produced by the two 

 sounds during this interval are counted. The chrouoscope itself records 

 the number of vibrations of its spring ; so that by adding to this the 

 number of the beats during the same time, the number of vibrations of 

 the fork may be determined to within about one-twenty-fifth of one 

 vibration. ( Anz. Ak. Wein, 1885, 221 ; J. Phys., May, 1886, IIj^v, 340.) 



Doumer has proposed to use manometric flames for the purpose of 

 measuring pitch. In principle the method is simple. Two manometric 

 flames are employed, placed near each other, one vibrating under the 

 influence of a sound whose pitch is exactly known, the other under that 

 of the sound to be measured. On measuring in the revolving mirror 

 how many vibrations of the latter correspond to a definite number of 

 the former, a simple proportion gives the j^itch. In practice, however, 

 it is not easy to obtain in this way exact results. The author has there- 

 fore made use of a moving sensitive plate and has photographed simul- 

 taneously the images of the two flames. These flames were of gas 

 treated with benzine and burnt in oxygen. A lens of short focus pro- 



