Benton — Properties of Catgut Musical Strings. 389 



influenced by humidity. In the enclosure containing the cat- 

 gut, the absolute humidity was constant, but the relative 

 humidity increased as the temperature fell ; and it may be that 

 under such conditions the material tends to absorb moisture 

 and thus increase in length. It is possible, therefore, that in a 

 perfectly dry atmosphere, the behavior of catgut under vary- 

 ing temperature might be quite different. 



Elasticity. — To get at the true elastic properties of the 

 material it would be necessary, after each change of load, to 

 wait until the disappearance of the after-effect before deter- 

 mining the corresponding length of the string. In strictness, 











/ 









/ 



/ 









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A 



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o l 



Loa.<L kg-s- 



an infinite time would be requisite for this ; but practically 

 the following procedure can be adopted, and was employed in 

 these experiments: After each change of load, observations on 

 the length of the string were made at intervals of a few hours 

 for several days, and corrected for thermal expansion. From 

 the data thus obtained, a curve was plotted with times for 

 abscissas and lengths for ordinates ; and from this curve the 

 final length which the string tended to reach with disappear- 

 ing after-effect, was estimated. Of course such an estimation 

 involves considerable uncertainty and arbitrariness ; but no 

 other course seems available, as long as experiments must be 



Am. Jour. Sci. — Fourth Series, Vol. XX, No. 119. — November, 1905. 

 27 



