322 On the Pitch and Scale of the French Harmonica. 



edition ohheEncyclnpcpdia Britannica, vol. ii. p. 650, of his dis- 

 covery, of the mode oj producing perfect musical Smivds, by the 

 mere opening and shutting of a stop-cock, tlirough tvhicli, slightly 

 compressed air, thus interryplcdly passed, at very quick inter- 

 vals, to which iliscovery the Baron appears now to lay clarfn, in 

 his account referred to. 



Those of your Readers who are conversant with Flarmonics, 

 can scarcelv fail to have regretted with me *, the want of precise 

 measures of the intervals of the Scale, which are actually pro- 

 duced, by the mos't expert and ap])rovedof the professionfil Tuners 

 of our common keyed Instruments. Such an instrument as the 

 Sirene, when properly constructed, and used with the requisite 

 care and precautions, seems capable of affording these measures; 

 it is however, abundantly apparent to me, that some or all of 

 these requisites have been wanting, in the experiments which the 

 Baron has recorded, as to the Pitch iind Scale of the Standard 

 French Instrument which he calls an Harmonica. 



In the first place I would observe, as to the pitch, that if the 

 Key Note ut, or c of this Instrument make 511 vibrations in 

 I", and the English concert pitch be 4 SO vibrations for the same 

 note, as I believe to be usually the case, this Harmonica was- 

 pitched 55s, or nearly a major Semitone, higher than our Eng- 

 lish Instruments are usually pitched or tuned f. 



The numbers given in the 2d and 3d columns of the Baron's 

 Table, are not in the ratio 1 to 13 "5, as the previous description 

 might have led one to suppose, but in the ratio \ to 22'5 or very 

 nearly so; and the whole descripiion is so concise, and withaU ko 

 confused, as to furnish no clue, for determining the accuracy of 



the 



state, that about two or three years ago, while he was engaged in preparing- 

 the elaborate iwi\c\e Steam- Engine, which is printed in Dr. Rees's Cyclopeedia, 

 Mr. Watt did us the honour to call here several times, and in my presence, 

 held various conversations with my Son, relating very fully to Mr. W's inven- 

 tions and improvements of the Steam-Englne, and relating to the rival claims, 

 which various persons have at di.?'erent times set up; into the particulars 

 of which rival claims, my Son had previously, spared no pains to inquire, 

 through every practicable channel, and having stated the conclusions to 

 which he had come, in each of such cases as regarded Mr. Watt's Steam- 

 Engine, by reading these parts of his Manuscript to Mr. W. he had the sa- 

 tisfaction of receiving, his full assent thereto : and I beg to declare, that in 

 these conversations, not the slightest complaint was made, of M. de Prony's 

 conduct ; nor on a liter occasion, when Mr. W., only a veiy few months be- 

 fore his death, called here, and left for my Son (who was from home at the 

 time) a oopy of his own Work on the Steam-Engine, not then published; on 

 ■which occasion Mr. W. sat and conversed with me for a considerable time, 

 on the subjects treated of in his newly printed Book. 



• See vol. xlix. p. 447- 



f The great improbability of the Continental Pitch being at thi* time 



higher 



i 



