August 8, 191 8] 



NATURE 



457 



and Key 



£.E 



0.5 



TABLfi W.— Spread Resonance of Lower Open Notes on Brass Instruments. 



Pkua,,; (h^) • ^No.2 No. 3 



Boosey 



Player Pkuai. 



D. J. Blaikley FF^GA^^A Bt ; F f6 G A;, A By 



I {120) i : "^ (240) 



E. If. Barton E F F| G A7 A Br» \ i Aj, A By I! 



Ar, A Bj B C D:» D E:» D E? 



E. C. Pickerill 

 E. H. Barton 



F G Af* .. By F G A, ... B7 



(120) (240) 



Ei^EFFjjGA^A By ; G A|, A : Bj> 



o.S { Millereaa 





5« 



,.2'^ 



:i-^ 



Boosey 



Boosey 



Boosey 

 Besson 



Boosey 

 Besson 



Boosey 



D. J. Blaikley 



E. H. Barton 



D. J. Blaikley 



E. H. Barton 



A. Wilkinson 



D. J. Blaikley 

 (March, 1913) 



Fg G Ai A , Bi (Eb) E F F| G Aly A • BJj 



(60) ^ ^"°) 



GA7A By B F| G Ai7 A B^ 



C Db D Eb E 

 Eb E 



F 



(90) 

 F 



F#...ABbB 

 Ft Bb B 



(•8o) 

 F F| 



C 



C Gj 



B^ B C C| D (E^) Ab A : B, 



■ (60) '■ (120) 



A ; Bi B C C^ D (Eb)E A I By V, 



(Ab) C Db D ; Ey 



£-> E F Fji G (Ab) A Cjf D I Ey E 



{40) ;, : \ (80) 



E F F;f G (Ab) C C^ D : Ey E 



Ey E F Fjf G (Ab) C^ D \ Ey E ¥ 



; full fair poor fair lull poor fair; full fair poor 



St cuiid l<n> on to a photographic plate in a dark 

 room. This plate was shot alon^ horizontal rails by 

 elastic cords, which were just slack when the plate 

 received the light. Thus the plate moved uniformly 

 and horizontally, while the shadow of the vibrating 

 string showed its special motion vertically. The corre- 

 sponding motions of bridge, belly, or air were ob- 

 tained on the same photographic plate by the light 

 reflected from a tiny rocking minor, the slight tilt 

 of which was produced by the motion of the part 

 under test. {The principle of this experimental 

 method was then demonstrated, the humped form of 

 the curve due to plucking the string and the two-step 

 zigzag produced by careful bowing being shown.) 

 F'.^- 3 gives a diagram of the method for the mono- 

 ihord, also a detail of the rocking mirror for the 

 bridge's motion. Fig. 4 shows photographic traces 

 for the monochord, string, and bellv. The two curves 

 alike were taken separately to test if the apparatus 

 worked satisfactorily. The other two curves, slightly 

 different from each other, show the tiistinction in 

 appearance between the records of a bad and those of 

 a good tone. In this work the assistance of Messrs. 

 C. A. B. Garrett and J. Penzer was acknowledged. 

 In iqi4 Prof. C. V. Raman, of Calcutta, by experi- 

 ments somewhat similar to the above, showed that 

 tii«^ forwar.i speed of a string where it i< h(i\\*<l !•.; 

 !. ntical with that of the bow itself. 



V 1 1 . — Violin Vib ra tions . 

 If the problems of the monochord were numerous 

 id complicated, tho.se of the violin are still more so, 

 T there are now four strings instead of one; further, 

 NO. 2545, VOL. lOl] 



all are different in thickness and pitch, and are capable 

 of use in sections of varying length. Again, the sound- 



2e:J 



11 of Opticul LtvtT >Dd Bridgs. 

 -P 



Monochord apparatus. 



bo.x is curved in a variety of ways. Finallv, the re- 

 inforcement of the bellv is asvmmetricai. The bass 



