NATURE 



[Oct. 15, 1874 



on the faintest hints of nature, and with more or less conscious- 

 ness of insight into law is able to control the process. 



The modem theory of musical quality, or timbye, for which we 

 are indebted primarily to Johannes MiiUer, and subsequently to 

 Helmholtz, who by elaborate investigation has made the subject 

 specially his o«n, takes account only of the varying intensities 

 of the harmonics present in the compound tone, classed in two 

 series, the " open " and the " stopped," or otherwise the "even" 

 and " uneven," in regular progression. To the system of asso- 

 ciated sounds in harmony the present inquiry has no reference ; 

 my purpose is to press the claim for recognition of another series 

 in addition to these, to show that quality, and especially mima- 

 phonic quality, in sounds, in whatever degree attributable to 

 harmonics combined with the fundamental, is no less dependent 

 for its character on the "order " in which harmonics come on or 

 develop themselves in the growth of the tone. In plants there 

 is a direct order of appearance — leaves, then flowers ; a reversed 

 order Is as natural, and flowers come before leaves. 



If an "open diapason " pipe of small scale is taken, and some 

 slight variation made in the voicing, the pipe may be converted 

 into a "flute harmonique," and it will give a note an octave 

 higher than before ; that is to say, the fundamental is abolished, 

 and the octave or first harmonic reigns in its stead. The pipe 

 will probably be now "unsteady," frequently attempting to 

 reinstate the fundamental. This tendency we may counteract 

 by drilling a small pin-hole at the side of the pipe, and the 

 trifling amount of external air thereby admitted will destroy the 

 tendency, by preventingfthe perfect formation of the node required 

 by the fundamental. The perforation should be made at the 

 true point of localisation of the node, which (as explained in a 

 former letter in Nature, vol. ix., p. 301) is at about 5 of the 

 whole length of p'.pe reckoned from the level of the mouth. If 

 we next enlarge the hole at the foot of the pipe, thus allowing 

 greater force to the wind-current, and if we have properly mani- 

 pulated the pipe, we sliall on the trial of its sound hear the twelfth 

 coming on as the forerunner of the octave, most distinctly and 

 with a perceptible interval between the appearance of the twelfth 

 and octave. The effect is more certain if the mouth is cut to a 

 height less than that marked by scale, which would be | of the 

 width of mouth ; and if, further, tire pipe is slightly coned — a pro- 

 vision favouring the harmonic. Ly other changes of treatment, 

 the fifteenth or double octave may be brought out as the intro- 

 ductory harmonic, and the twelfth following, and if we will we 

 may restore the original ground-tone. The " flute harmonique " 

 in this style is to be chosen for this experiment, not as repre- 

 sentative of quality, but that in this overstrained condition it 

 clearly defines the entrance of each harmonic, the order of suc- 

 cession, and the interval between each. In other varieties of pipe 

 the "quality" is characterised by these harmonics, and in this 

 order, but so blended as it were in a "portamento" glide that 

 even critical ears fail to detect the elements combined into the 

 effect. It is, so to speak, "an excess "of nature, which is ol ten 

 necessary to open our eyes to the perception of her commonest 

 realities. 



A diapason pipe is never so strong and brilliant in character as 

 when it is just verging on the transmutation of fundamental to 

 octave ; for good vigorous quality, therefore, it is restrained only 

 to just within the Umit ; nevertlieless the presence of the octave- 

 harmonic as the precursor of the fundamental should always be 

 felt with its jubilant energy, then afterwards, the fundamental 

 taking full possession of the pipe, producing its own octave- 

 harmonic with almost equal exuberance of power. The pre- 

 cursory harmonic is of the transitive order. We have to 

 recognise two distinct series of open harmonics— the direct 

 order, mer-toncs of the pipe, which are derivatives of the funda- 

 mental, and the inverse order, the tones of which may be called 

 stem-tones oj the reed, for they are thrown off by the reed in swift 

 succession, and declare the non-isochronous nature of the air- 

 reed's motion. There is nothing erratic about these stemnal 

 harmonics or the order of their apjjearance ; they are due to the 

 untamed vigour of the reed, and have this distinguishing law — 

 they are transitive, each one dies in giving birth to tlie next, 

 whereas the over-tones of the pipe coexist with the fundamental, 

 and are the direct consequence of the excess of excitation in the 

 air-column of the pipe (see more at length in Nature, vol. \iii. , 

 p. 3S3), providing a safety-valve for the permanence of pitch in 

 the ground-tone, by employing the surplus energy acquired from 

 the reed's vivacity in new forms of growth. 



Whenever from an organ-pi[)e we hear harmonics together 

 with the fundamental, then the air-reed is vibrating to its fullest 

 mpUtude, for it is the superabundant vitality of the air- column 



that sustains the coexistent ones ; but when we hear harmonics 

 independent of the fundamental, then we may be sure that tliey 

 are the expression of the higher activity of the reed itself, then 

 working with lessened amplitude of motion, yet with greater 

 velocity of vibration. 



The genesis of these tones is due to the association of reed and 

 pipe. 'iVithout the pipe the reed could not produce tone, would 

 be barren as one sex. As the pipe is silent and requires some 

 external impulses to bring it into life, so the air-reed needs some- 

 thing to act upon before it can vibrate or swerve from its course 

 in minute degree ; some inequality of environment is all it asks — 

 some alliance with power distinct from its own. Take away the 

 jiipe, leave it only the mouth, and it will pull against that and 

 begin to work according to its nature, and even in that rudimen- 

 tary condition will elicit tone of definite pitch. 



Many classes of organ-pipes give harmonics of tlie direct order 

 without a trace of those of the inverse order ; on the other hand, 

 the several varieties of pipes which give the inverse order invari- 

 ably yield the direct order subsequently with the ground tone ; 

 and why ? It will be comprehended at once, if I have rendered my 

 meaning clearly, that the initial harmonics proclaim the intense 

 vigour of the reed, and that force, unabated in strength, although 

 widened in scope, is transferred to the air-column of the pipes 

 The difi:erence of effects produced by the two orders constitute, 

 that variety of quality which distinguishes string-tone from horn- 

 tone, and a further modification chiefly in relative times of se- 

 quence asserts its peculiarity as reed-tone ; yet, again, there are 

 in both series departures from truth of pitch, in some qualities 

 an over-flatness of one or more harmonics, and in some an over- 

 sharpness. The blast of the trumpet combines both flat and 

 sharp harmonics strongly. The direct order of harmonics may 

 be likened to an ascending arpeggio coalescing into a chord — the 

 transitive to a descending arpeggio, in some instances having 

 intervals regularly defined, in others starting abruptly and with 

 wayward intensity, and in other displays ]iassing swiftly onward 

 to the fulness of tone, imperceptibly blended as is the " porta- 

 mento " glide of voice or string. 



In all the " Geigens " and " Gambas " and similar organ-pipes 

 mimaphonic of "stringy quality," the transitive harmonics are 

 the true cause of their speciality. Numerous experiments prove 

 this to the eye as well as to the ear. I shall be able to show that 

 the ' ' Gambas " are characterised also by an over-sharpness of these 

 transitive harmonics, and this paper is a necessary introduction 

 to my proposed examination of the mode in which the peculiar 

 quality of tone is built up in this attractive class of pipes. 



Hermann Smith 



Can Land-Crabs Live under Water? 



Permit me to inform Mr. J. C. Galton that the authority for 

 my statement in the "Outlines of Physiology" is also derived 

 from " some book or other ; " and that this " turns out " to be 

 the classical " Hist. Nat. des Crustaces " of Milne- Edwards, 

 vol. ii. pp. 16, 18, with which perhaps your correspondent is 

 unacquainted. 



Milne-Edwards, in his tuni, refers (p. 19) to those who have 

 studied the land-crabs in the Antilles and on the South American 

 coast, viz. , Rochefort, Feuillee, Labat, and Brown. He else- 

 where, also, treats tlie subject as a comparative anatomist and 

 physiologist (Ann. des Sciences Nat. ; Todd's " Cyclopxdia"). 



Whether the land-crabs of the east differ in their habits from 

 those of the west is of course open to inquiry ; and also in what 

 ways (cither anatomically or physiologically) they dift'er; but the 

 question is clearly not whether they can survive for a few hours 

 under water, but whether practically they can live in that element 

 or are at last asphyxiated in it. 



10, Savile Row, Oct. 6 John Marshall 



Bright Meteors 

 At 8.55 this evening a party of six observed a meteor in the 

 constellation Aries, or below it, which emitted light sufiicient to 

 cast a bright gleam on the neighbouring trees. The body of the 

 meteor shot rapidly along a course extending about 20". It then 

 seemed to explode suddenly, and its track was luminous for a 

 short time. The granular debris of the meteor continued to 

 pursue„with very much retarded velocity a path slightly deflected 

 from its former course : it continued to do so for several degrees' 

 and it was, I think, fully a minute after the explosion that 

 several of us almost simultaneously exclaimed, "It is falling." 

 It resembled the expiring light of one globe of a rocket charged 



