456 PROCEEDINGS OF THE AMERICAN ACADEMY. 



than it purports to be, making, according to Koenig, 435.45 double vibra- 

 tions per second instead of 435, when at the temperature of 15° C, and 

 making exactly 435 vibrations only at the temperature 24.26° C. But 

 the legal French pitch was defined by the rate 870 single vibrations, and 

 not by the fork constructed by the Commission. Moreover the standard 

 French forks made by Koenig wei*e substantially correct in rate. The 

 difference is, of course, too slight to be of any consequence in practice. 



The International pitch has come to be generally adopted, so that it 

 is now the standard pitch of this country, although it seems to be custom- 

 ary to tune pianos for use at concerts somewhat sharp, even up to A3 

 440 vibrations, which is in fact the " Stuttgart pitch " of 1834. 



At various times dux'iug the past twenty years the writer has taken the 

 opportunity to ascertain the rates of such tuning-forks and other stan- 

 dards of pitch as were accessible. The results of a considerable number 

 of these measurements were published in the "American Journal of 

 Otology" for October, 1880, in a paper "On the Present Condition of 

 Musical Pitch in Boston and Vicinity," by Charles R. Cross and William 

 T. Miller. The later measurements have not hitherto been 2:>ublished. 

 These have been made in part by the writer and in part by several of 

 his assistants in the Rogers Laboratory, Messrs. Goodwin, Mansfield, 

 Wendell, and Burgess. The present paper is intended to include such 

 results as are likely to be of general interest. 



Table I. is reprinted from the paper of Messrs. Cross and Miller. 

 The tonometer forks available at the time of its publication were less 

 accurate than those which have been procured subsequently, so that in 

 certain cases, where the standards measured in 1880 were still accessible 

 a remeasuremeut has recently been made, the results of which will be 

 found in Table II. Where this has been done, it is indicated in the 

 tables by an asterisk prefixed to the number designating the standard. 

 By a comparison of Tables I. and II. it will be seen that the remeasure- 

 ments have not materially altered the values obtained in the eariier 

 measurements. 



The standard C fork upon which the measurements of 1880 were 

 based was a C3 fork (No. 1 of Table I.) by Koenig, belonging to the 

 Massachusetts Institute of Technology, the rate of which had been deter- 

 mined by comparison with a C3 fork by Koenig belonging to the Stevens 

 Institute of Technology, which last fork had been very carefully rated 

 by Professor A. M. Mayer of that institution. The standard A used 

 was a fork by Koenig assumed to be exact. From these the forks of an 

 improvised tonometer were rated, the C forks being of pitch C3 and 



