200 SEC. 6. SOUND. 



786. Stand of Apparatus illustrating the progress of 

 CEolian Principles. J. Baillie Hamilton. 



1. Primitive JEolian types. 



The rod. 

 The bow. 

 The harp. 



2. Modern CEolian harp. 



3. Wind concentrated upon a string, and applied to its entire 

 length. By Professor Robinson. 



4. Wind applied to a portion of the string, as by Wheatstone, 

 Green, Isoard, &c. 



5. Further modifications of the same. 



6. Use of a free-reed. By Pape. The connexion with the 

 string being effected by a silk thread. 



7. Julian's mode. A metal string flattened into a tongue at the 

 part where the wind impinges. 



8. Farmer's mode. A reed-tongue substituted for the flattened 

 portion. 



9. Farmer and Hamilton's mode. A rigid connexion between 

 reed-tongue and string allows the reed to be used as in reed- 

 organs. 



SUBSEQUENT INVESTIGATIONS BY HAMILTON IN CONJUNCTION 

 WITH HERMANN SMITH. 



10. Improved string-organ note, in which a sympathetic re- 

 sistance is offered to the string, the vibration transmitted to the 

 soundboard, and constancy of pitch preserved by a spring -bow. 

 The reed tone is modified by a tube, and the connexion effected 

 through the tube by a " purse," the latter suggested by Hermann 

 Smith. 



11. Further modification by Hamilton. The necessity for the 

 " purse " abolished by setting both reed and string inside the 

 register. The economy of space effected by Hamilton's spiral 

 spring, and the use of a short metal spring-bow. 



12. Application of these improvements for use in a wind- 

 viol. Also a conical string, invented by Hamilton, for obviating the 

 following difficulties peculiar to reeds and strings in combination. 



a. The difficulty caused by the string breaking into segments, 



owing to the constraint on the reed, and the scarcity of 

 notes obtainable. 



b. By the irregularity of intervals which, in a cylindrical string, 



are crowded together near the reed, and are far apart when 

 remote from it. 



c. By the irregularity of tone in different portions of the string's 



length. When an ordinary string is used in short lengths 

 the reed's motion is confined, and the tone is consequently 



