1881.] on the Musical Pitch of Harmonium Reeds. 415 



I and III, II and III. The results marked f should, I think, be re- 

 jected, because of the probable alteration in reeds 22 and 23, the 

 badness of the observation on reed 26 pitch III, and the too great 

 closeness of the temperatures for pitches II and III. Rejecting these, 

 we obtain , as the mean of the results from I & II, and II & III respec- 

 tively, the coefficients '0000938 and '0000930 ; so that either '00009 or 

 •0001, that is, an alteration of 9 in 100,000 or 1 in 10,000 vibrations 

 in a second for each change of 1° F. may be used with tolerable 

 certainty, diminishing for heat and increasing for cold. Thus a 

 tuning-fork like Scheibler's of 440 vibrations at 59° F. (his standard 

 tuning A), an harmonium reed like Appunn's, and an open metallic 

 flue-pipe of an organ, both in unison with the fork at the same tempe- 

 rature (the last having a coefficient of "00104 acting in the opposite 

 direction) would become 439*56, 439T2, and 449'IS, at 79° F. respec- 

 tively, so that it would be quite impossible to play the organ and 

 harmonium together. 



Table of the Pitch of Reeds at different Temperatures. 







Pitch of the Reed. 



Coefficient of Temperature. 



No. of 

































Reed. 



I 





II at 



III at 



From 



From 



From 







at 



73°. 



79°. 



I and II. 



I and III. 



Hand III. 







254-04 



55°-5 



253-67 



253 55 



•000 0844 



•000 0976 



f -000 0723 



3 



266-11 





265 55 



26541 



1192 



1114 



f816 



9 



289-96 



55° 



289-45 



289 30 



1159 



948 



f864 



14 



309 66 





309-18 



309-06 



861 



807 



f647 



22 



341-31 



53° 



34091 



340-76 



f586 



f620 



f733 



23 



345-35 



;> 



34488 



344-65 



f680 



f780 



flll2 



25 



353 50 



5J 



35292 



35266 



820 



914 



fl223 



26 



357 51 



J> 



356-90 



f356-85 



853 



fll25 



f0234 



33 



385-30 



59° 



384 77 



384-64 



945 



960 



f563 



36 



397-20 





396-75 



396 55 



809 



818 



f840 



43 



424-. h 8 



60° 



424-42 



42423 



1014 



929 



f746 



46 



43671 





436-21 



435-96 



881 



904 



|955 





Mean, rejecting results marked f, 



•000 0938 



•000 0930 





