C II R 



loo 



C H R 



tree in its own fundamental key, and for modulating in- 

 to other key*. The late Mr Charles Clagget invented, 

 and took out a patent a short time previous to 1790, and 

 for a time made double horns and trumpets, one of which 

 wa tuned half a note lower than the other, and by means 

 of a connected mouth-piece to these tubes, in which 

 there was a valve moveable by the finger, the performer 

 could tound either of these tubes at pleasure, and thus 

 it was pretended, that a scale was produced, by some- 

 time* using one tube and sometimes the other for differ- 

 ent notes, and that the instrument was thus perfected for 

 all the keys in which music is usually written. The fol- 

 lowing expression! for the notes of the horn or trumpet 

 in ratios, to the whole length of the tube as unity, and, 

 in our usual notation, will shew the fallacy of these pre- 

 tensions, and prove useful on other occasions to the mu- 

 sical calculator, viz. 



In the column of ratios, the denominators shew the or- 

 der in which these 12 notes arise by harder and harder 

 blowing in the same tube ; and the numerators, as mul- 

 tiples of 2, shew the successive octaves upwards, in which 

 these notos are produced. In the last column, the tem- 

 peraments or errors of the false notes of horns and trum- 

 pets are shown j thus the 4th of the key of C is 27 

 schismas and more too harp, and the major sixth of the 

 same key nearly 22j- schismas loojlat, &c. ; whence it is 

 abundantly evident, that no livo tubes can mutually sup- 

 ply or correct the false notes of the other, as Mr Clag- 

 get's invention assumes ; nor will the same succeed any 

 better, in fitting it for transposition or modulation into 

 other keys, as will be easy for any one to try, by adding 

 612Z + 12/+53 m to each of these notes in col. 3 for 

 another octave above this, and then from these, when 

 necessary, deducting the value of the note that is assu- 

 med as the new key, and comparing the difference with 

 the perfect intervals in Plate XXX. Vol. II. whence the 

 temperaments, or errors from the respective consonances, 

 will appear for the octave above the new key, as they do 

 in this table for that above C. 



French-horns, bugle-horns, and trumpets, have of 

 late been made by Mr Perceval, of St James's Street, 

 with six side finger-holes, as in a flute, for supplying the 

 notes that are false on the common instruments. It is 

 trident, however, that though a considerable approach 

 may be made on such polyphonian or chromatic horns, 



:. by the adjujtment of the places of the holes on the 

 tube, to a perfect scale in C, or any other key, or even 

 to any assumed tempered scale ; yet it is well known, 

 that modulation cannot be truly effected by help of any 

 12 notes whatever, except in that most inharmonious of 

 all systems, the equal trmjxrament, which no good ear 

 tould endure to hear iu the few trial* that have beeo 



7 



made of it, much as it is talked and written about. The chromatic, 

 slide for lengthening or bhortciiinjj the tube ol ^---^-^^ 



trumpet, which Mr Hyde has long used with su-:h good 

 effect in our best concerts, and the regulation ot the 

 notes on the horn which the Petridcj etTect, by thrust- 

 ing their hand or a turned block of wood into the 

 mouths of their horns, have not the effect of chrom... 

 trumpets or horns, of which we ha\ ,-eaking, 



where the scale consists of half-tones only ; but by thu 

 management they become perfect instruments, /com- 

 bined with the crooks that the latter use in different 

 keys,) on which they can effect any of the small changes, 

 for producing perfect harmony with the other notes of 

 the piece, as on vi >lins, voice*, and Mr Listen's organ. ({) 

 CHROMATIC INTERVAL, the great -r, ut Wood 



and Gregory, has a ratio of .,=57S+f+5m, and is the 



r SEMITONE S ; which see. ((} 

 CHROMATIC Interval, the lesser, ot Wood and Grc- 



"t 

 gory, has a ratio of ,=362 + f+3i, and is the M:- 



KO 



nor SEMITONE S ; which see. (j) 



CHROMATIC SEMITONE, greater, of Dr Callcott, 



128 

 has a ratio of ^-"--_,=472 + f+4.'M, and is the SEMI- 



TONE Mediiis, S ; which see. ({) 



CHROMATIC Semitone, lesser, of Dr Callcott, S. Root- 



sey, M. Tartinig, &c. has a ratio of ~ ,=362+f+3/rt. 



and is the SEMITONE Minor J. Dr Callcott in Art. 

 228, 1st Edit, of his " Grammar," has shown that 

 these two chromatic semitones exist in the real , ac- 

 cording as they result from Tort, viz. T=S and t = S; 

 but unfortunately, in Art. 163 to 175, '21 '2 to 224, 

 315, &c. this essential distinction is not observed ; 

 but the term chromatic semitone is used synonymously 

 with FLAT and SHARH. See those Articles in our 

 work, and the Philosophical Magazine, Vol. xxxix. 

 p. 375. ( ? ) 



CHROMATICUM INTERSUM, in the Greek Mu- 

 sic, was distinguished among their genera, according to 

 Ptolemy, by a tetrachord, ascending according to the 



. 21 11 6 3 ,. 



following numerical ratios, viz. x .-; X z = -, which 



z2 12 / 4 



intervals, in the notation which we have adopted, (see 

 Plate XXX. in Vol. II.) are as follows, vi/. 



= 1 36.0529042 + 3f + 1 2m 

 |i= 76.7482942 + 2f+ 7m 

 -l\= 41.1988022 + 3m 

 4th = 25 1,0000002 + 5t + '22m ( ? ) 



CHROMATICUM MOLI.E, or soft chromatic, had, 

 according to Euclid, a tetrachord ascending by a triental 

 diesis, another such diesis, and a spiss or incompositc 

 interval making up the fourth. This in our notation it 

 as follows, viz. 



184.7664422 + 3f+16m 

 $T= 34.6167792+ f+ 3m 

 |T= 34.6167792+ f+ 3m 

 4th=254.0000002 + 5f+22m 



The first of the above intervals was, it is said by Hol- 

 der, accounted to be, " a tone and half and third part 

 of a tone, that is, 1J of a major tone, but which is 

 = 190.620711 2 + 4f+ 16m; differing 6.003931S from 

 the above, or half the diaschisma, or Ut, what Galileo 

 and Glarcanui call a sclrixma. 



