1865.] Squire on the Quality of Musical Sounds. 591 



to the railway companies, in affording increased confidence, and 

 therefore promoting extra travelling, on the part of the public. 



APPENDIX. 



Copy of Instructions to Enginemen, Guards, and all Parties concerned on the 

 South-Western Railway. 



Electric Communication between Passengers and Guard. 



Some of the trains are now fitted up with an electric communication between 

 passengers and guards. In the event of something of a serious nature occurring, 

 which urgently requires the stoppage of the train, the passenger may "break the 

 glass," "and King" by moving the bell handle in the direction denoted by the 

 arrow : — Thereby a bell will ring in each guard's van in the train, and also on the 

 engine. 



When the guards and enginemen hear the bell ring, they will at once look care- 

 fully along each side of the train, and in case any violent oscillation be seen, or a 

 carriage be on fire, or other occurrence of a serious character be observed, the train 

 will be stopped as speedily as possible, and, when stopped, must be protected by 

 signals as prescribed by the Rule book. 



Should, however, the guards and enginemen fail to observe anything which 

 really necessitates an immediate stoppage of the train, their duty will be to stop the 

 train at the next station or junction, so as to protect the train, when stopped, by 

 fixed signals. 



When the train is stopped the passenger who broke the glass and rang the bell 

 will communicate with the guard ; but should he fail to do so, the guard will detect 

 the compartment from which the passenger gave the alarm by looking for the 

 broken glass, and in case the alarm has been mischievously and wantonly given, or 

 from insufficient cause, the names aud addresses of all the passengers in that com- 

 partment will be taken, in order that the law may be enforced. 



The Bell Signal Code between Guards and Enginemen is as follows : — • 



One Beat ..... Acknowledgment. 

 Two Beats . . . . . Go on ; all right. 



Three Beats .... Look out ; something wrong. 



Four Beats ..... Shut off steam ; pidl up, and stop 



at next station or junction. 



Six Beats ..... Danger ; stop at once. 



Every signal must be acknc 

 ;iven by one whistle. 

 London, 10th August, 1865. 



Every signal must be acknowledged. The acknowledgment by enginemen will 

 be given by one whistle. 



ON THE QUALITY OP MUSICAL SOUNDS. 



By W. Stevens Squire, Ph.D., F.C.S. 



Though Music, as an art, is tolerably ancient, the investigation of the 

 physical principles upon which it depends has only just commenced. 

 There is, perhaps, no art in which physics come so much into play. 

 With the exception of the human voice, which is itself the most 

 delicately constructed instrument imaginable, nothing can be done in 

 music without artificial apparatus, generally of a highly complex 

 character, requiring as much skill on the part of the workman as the 



