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It follows that the amplitude of any term in a sine curve deduced from only a moderate number of observations must be received with caution until an investigation of its probable error has been made, and this remark refers especially to the second and higher terms where the amplitudes are so often small. W. H. DINES.
Benson Observatory, Wallingford, July 29.
ON THE CHARACTER OF THE "S" SOUND.
SOME OME two years ago I asked for suggestions as to the formation of an artificial hiss, and I remarked that the best I had then been able to do was by blowing through a rubber tube nipped at about half an inch from the open end with a screw clamp, but that the sound so obtained was perhaps more like an ƒ than an s. "There is reason to think that the ear, at any rate of elderly people, tires rapidly to a maintained hiss. The pitch is of the order of 10,000 per second." 1 The last remark was founded upon experiments already briefly described 2 under the head "Pitch of Sibilants."
Doubtless this may vary over a considerable range. In my experiments the method was that of nodes and loops (Phil. Mag., vol. vii., p. 149 (1879); Scientific Papers, I., p. 406), executed with a sensitive flame and sliding reflector. A hiss given by Mr. Enock, which to me seemed very high and not over audible, gave a wave-length (A) equal to 25 mm., with good agreement on repetition. A hiss which I gave was graver and less definite, corresponding to λ=32 mm. The frequency would be of the order of 10,000 per second, more than 5 octaves above middle C.
Among the replies, publicly or privately given, with which I was favoured, was one from Prof. E. B. Titchener, of Cornell University, who
Lord Rayleigh's sound more like an ƒ than an s is due, according to Köhler's observations, to a slightly too high pitch. A Galton whistle, set for a tone of 8400 v.d., will give a pure s.
It was partly in connection with this that I remarked later that I doubted whether any pure tone gives the full impression of an s, having often experimented with bird-calls of about the right pitch. In my published papers I find references to wave-lengths 312 mm., 1304 in. =33°1 mm., 128 in. = 32'5 mm.5 It is true that these are of a pitch too high for Köhler's optimum, which at ordinary temperatures corresponds to a length of 40'6 mm., or 1'60 inches; but they agree pretty well with the pitch found for actual hisses in my observations with Enock.
mouth, and a series of observations might be taken upon material composed partly of the natural (mouth) sounds and partly of the artificial (whistle) tones. If a listening observer were unable to distinguish between the two stimuli, and if the mouth sound were shown, phonetically, to be a true hiss, then it would be proved that the whistle also gives an s, and Lord Rayleigh would be answered.
The experiment was more troublesome than I had anticipated; but I may say at once that it has been carried out, and with affirmative result.
A whistle of Edelmann's pattern (symmetrical, like a steam whistle) was used, actuated by a rubber bulb; and it appears clear that a practised operator was able to imitate the whistle so successfully that the observer could not say with any certainty which was which. More doubt may be felt as to whether the sound was really a fully developed hiss. Reliance seems to have been placed almost exclusively upon the position of the lips and tongue of the operator. I confess I should prefer the opinion of unsophisticated observers judging of the result simply by ear. The only evidence of this kind mentioned is in a footnote (p. 328): "Mr. Stephens' use of the word hiss was spontaneous, not due to suggestion." I have noticed that sometimes a hiss passes momentarily into what may almost be described as a whistle, but I do not think this can be regarded as a normal s.
Since reading Prof. Titchener's paper I have made further experiments with results that I propose to describe. The pitch of the sounds was determined by the sensitive flame and sliding reflector method, which is abundantly sensitive for the purpose. The reflector is gradually drawn back from the burner, and the positions noted in which the flame is unaffected. This phase occurs when the burner occupies a node of the stationary waves. It is a place where there is no to and fro motion. The places of recovery are thus at distances from the reflector which are (odd or even) multiples of the half wave-length. The reflector was usually drawn back until there had been five recoveries, indicating that the distance from the burner was now 5×λ, and this distance was then measured.
The first observations were upon a whistle on Edelmann's pattern of my own construction. The flame and reflector gave λ=1'7 in., about a semi-tone flat on Köhler's optimum. As regards the character of the sound, it seemed to me and others to bear some resemblance to an s, but still to be lacking in something essential. I should say that since my own hearing for s's is now distinctly bad, I have always confirmed my opinion by that of other listeners whose hearing is good. That there should be some resemblance to an s at a pitch which is certainly the predominant pitch of an s is not surprising; and it is difficult to describe exactly in what the deficiency consisted. My own impression was that the sound was too nearly a pure tone, and that if it had been quite a pure tone the resemblance to an s would have been less. In subsequent observations the pitch was raised through
λ=16 in., but without modifying the above impressions.
Wishing to try other sources which I thought more likely to give pure tones, I fell back on bird-calls. A new one, with adjustable distance between the perforated plates, gave on different trials = 18 in., λ=1'6 in. In neither case was the sound judged to be at all a proper s, though perhaps some resemblance remained. The effect was simply that of a high note, like the squeak of a bird or insect. Further trials on another
day gave confirmatory results.
The next observations were made with the highest pipe from an organ, gradually raised in pitch by cutting away at the open end. There was some difficulty in getting quite high enough, but measures were taken giving λ=22 in., λ=1'9 in., and eventually λ=1'6 in. In no case was there more than the slightest suggestion of
As I was not satisfied that at the highest pitch the organ-pipe was speaking properly, I made another from lead tube, which could be blown from an adjustable wind nozzle. Tuned to give λ= 16 in., it sounded faint to my ear, and conveyed no s. Other observers, who heard it well, said it was no s.
In all these experiments the sounds were maintained, the various instruments being blown from a loaded bag, charged beforehand with a foot blower. In this respect they are not fully comparable with those of Prof. Titchener, whose whistle was actuated by squeezing a rubber bulb. However, I have also tried a glass tube, 10'4 in. long, supported at the middle and rubbed. with a resined leather. This should be of the right pitch, but the squeak heard did not suggest an s. I ought perhaps to add that the thing did not work particularly well.
It will be seen that my conclusions differ a good deal from those of Prof. Titchener, but since these estimates depend upon individual judgment, perhaps not uninfluenced by prepossessions, they are not fully satisfactory. Further independent aural observations are desirable. I fear a record, or ocular observation, of vibrations at so high a pitch is hardly feasible.
I may perhaps be asked if a characteristics, having a dominant pitch, is not a pure tone, what is it? I am disposed to think that the vibration is irregular. A fairly defined pitch does not necessitate regular sequences of more than a few (say 3-10) vibrations. What is the state of affairs in an organ-pipe which does not speak well, or in a violin string badly bowed? An example more amenable to observation is afforded by the procession of drops into which a liquid jet breaks up. If the jet is well protected from outside influences, the procession is irregular, and yet there is a dominant interval between consecutive drops, giving rise under suitable conditions to a sound having a dominant pitch. Vibrations of this sort deserve more attention than they have received. In the case of the s the pitch is so high that there would be
opportunity for interruption so frequent that they would not be separately audible, and yet not so many as to preclude a fairly defined dominant pitch. I have an impression, too, that the s includes subordinate components decidedly graver than the dominant pitch.
Similar questions naturally arise over the character of the sh, f, and th sounds.
NTERCHANGEABILITY forms the basis of manufacture wherever there are a large number of articles to be made, and the processes required in order to secure it are well understood. The system makes it possible to subdivide the manufacture of any part into many small processes, each effected by one worker, aided by machine or hand tools, who acquires great skil in his particular operation. The parts so made must be capable of being assembled with the minimum labour; in fact, assembling ought to consist merely of putting together parts selected at random from stocks of details, with the certainty that these will fit without any additional tool work on the part of the assembler. Each operation performed in the making of any part must give to that part definite dimensions within prearranged limits. The precise dimensions and limits are chosen with a view to securing running, push, driving, or shrinking fits, according as will be required in the assembling operations. Gauges by means of which the results of each operation may be tested thus become a necessity in the manufacture of interchangeable parts. These gauges are generally of the limit form. Very large numbers of these gauges are required in the production of munitions.
Suppose the operation to consist of boring a hole nominally 1 in. in diameter, and that the finished hole must not exceed 1003, nor be less than o'997 in. in diameter. The gauge employed would be cylindrical, having one end 1003, and the other end o‘997 in. in diameter. If the smaller end can go into the hole, the hole is not less than o'997 in. in diameter, and if the larger end cannot go in, the hole is not larger than 1003 in. diameter. By use of a gauge of this kind, any workman of ordinary intelligence may produce work having a high degree of accuracy.
It is obvious that the gauges employed must be much more accurate in dimensions than the work which they are employed to check. Thus the gauge mentioned above would have its larger end probably within the limits 10031 and 1'0029, the variation permitted being one ten-thousandth inch above or below the rated size. Further, gauges must be made of very hard material in order to reduce wear, and must have well-finished surfaces. The hard steel used for this purpose is often of such quality as to require annealing once or twice before the necessary machining operations can be completed. After machining nearly to the finished size, the gauge is hardened, a process which generally warps the material.
To correct this, and to bring the gauge to the proper dimensions, grinding and lapping by machines or hand is required. It will thus be understood that the whole operation of gaugemaking is one which requires great skill, and a special plant.
Many of the gauges used in engineering manufactures are made by firms who lay themselves out specially for this class of work; in other cases the manufacturing firms make their own gauges. The latter plan has nothing against it, provided that the whole of the parts required in the finished products of the firm are made in their own factory. This is a point of importance at the present time, when most engineering firms have been called into the making of munitions. It is clear that the produce of any one firm producing certain parts must agree, within the prescribed limits of accuracy, with that of any other firm making the same parts. Hence all must be supplied with gauges having like limits of accuracy.
the standardisation of dimensions in a similar way to that in which are maintained our standards of weights used in distributive trades.
The National Physical Laboratory has recently been carrying out a useful piece of work in determining the desirable manufacturing limits for B.A. screws. Gauges for testing screws present peculiar difficulties in manufacture, as will be realised from what has been said above. The "fit" of a screw having a V thread in a tapped hole depends chiefly upon the effective diameter of the threads (i.e., the diameter measured between the sloping sides of the thread), on the pitch, and on the correctness of the angle of the V. The National Physical Laboratory has issued tables giving recommendations(some of them provisional) for B.A. threads Nos. 0, 1, 2, 3, 4, 5, 6. The scope and importance of the recommendations may be understood by examination of the accompanying table, which we have abstracted from a number of tables in the report.
It is well known, as has been pointed out by a correspondent in the Morning Post, that the firms of gauge-makers have not been able to keep pace with the demand, and that many firms have been hindered in the starting of the manufacture of munitions by delay in the supplying of gauges. It is very easy to say now that the emergency might have been foreseen earlier. A very useful suggestion was made at a recent meeting of the Institution of Mechanical Engineers to the effect that all gauges should be made and supplied from a central factory. It may not be altogether a dream to imagine such a factory under direct. government control, as is the case in Woolwich Arsenal, and working in conjunction with the National Physical Laboratory in order that standards may be maintained. Such an institution would be of great benefit to engineering manufacture, quite apart from the present war conditions, and could be worked so as to secure
451° 453° 461° 491° 48°
The gauges recommended are (a) a screwed plug gauge; (b) a screwed ring gauge; (c) a plain cylindrical "go in" gauge; (d) a plain cylindrical "not go in " gauge; (e) a 'go in" ring gauge; (f) a "'not go in ring gauge. Gauge (b) would be specified to have the same thread form as the plug gauge (a) and would be checked by its fit upon the latter. Gauge (c) is of standard nominal core diameter, and should fit in gauge (b); gauges (c) and (d) serve the purpose of testing the core diameters of units and tapped holes. Gauges (e) and (f) are for testing the full diameters of screws.
The results of the investigation are bound to be of service at the present juncture to instrument makers and others using B.A. threads. The National Physical Laboratory is prepared, pending an authoritative decision on the matter, to certify screws, etc., which fall within the suggested limits, as B.A. screws, taps, or gauges.
R. BRUCE is to be congratulated on the pubDR. lication of the fourth volume of the scientific results of the voyage of the Scotia. This stately publication contains no fewer than nineteen reports (all by British investigators) on the vertebrate animals collected by the expedition, and it seems to us well worthy of the generosity, notably on the part of Sir Thomas Glen Coats, which has made its publication possible. Many of the reports have appeared previously in the transactions of scientific societies, as is carefully noted in each case, but the utility of having all the papers together is obvious.
Beginning with the mammals, we find a report by Dr. Bruce on the dimensions and weights of the Antarctic seals captured by the Scotia, and the editor also contributes a series of fine photo
microscopic) of a foetal sea-leopard, Stenorhynchus leptonyx) and with the minute structure of the central nervous system of the Weddell seal. Bruce gives data in regard to seven Antarctic whales, and also discusses an interesting piebald porpoise (probably Lagenorhynchus cruciger). Mr. Theodore E. Salvesen's graphic account of the southern whale fisheries has been recently reviewed in NATURE (vol. xciv., p. 678, February 18, 1915).
Turning to the birds, we find a masterly account of the birds of the South Orkney Islands, the Weddell and adjacent seas, and Gough Island, by Mr. Eagle Clarke, of the Royal Scottish Museum. The birds observed and collected by the Scotia at other places have been dealt with in a number of short papers by the late Lieut. Lewis N. G. Ramsay, a young zoologist of great promise, who was, alas! killed at Neuve Chapelle in March of this year. Dr. R. N. RudmoseBrown gives a vivid picture of the habits of penguins. Profs. D. Waterston and A. Campbell Gaddes deal with some anatomical features of the Emperor penguin and with the development of Gentoo and Adelie penguins. The extraordinary curvature of the cervical region region of the penguin's vertebral column is carefully discussed, and an interesting contrast is made between the development of the duck's wing and that of the penguin's paddle.
graphs of the Weddell seal, the sea-leopard, the crab-eater, the Ross seal, and the Patagonian sealion. Dr. R. N. Rudmose-Brown gives a very interesting account of the habits of four Antarctic seals (Weddell, crab-eater, sea-leopard, Ross seal), and the value of his personal observations is increased by numerous beautiful photographs. Prof. David Hepburn deals with the brain, the abdominal viscera, the respiratory organs, and the urogenital system of a young male Weddell seal (Leptonychotes weddelli); Prof. Robert Thomson with the skeleton of the Ross seal (Ommatophoca rossi); and Dr. Harold Axel Haig with the structure (macroscopic and
1 Scottish National Antarctic Expedition. Report on the Scientific Results of the Voyage of S. Y. Scotia during the Years 1902, 1903, and 1904, under the leadership of W. S. Bruce. Vol. iv., "Zoology." Parts ii-xx. Vertebrates. Pp. xi+505 +62 plates+2 maps. (Edinburgh: The Scottish Oceanographical Laboratory, 1915.) Price £2 10s. net.
An important report on the Antarctic fishes comes from the skilful hands of Mr. C. Tate Regan, who describes seven new genera and twenty-one new species. The first of the new genera, Eugnathosaurus, is based on a remarkable head taken off Coats Land at a depth of 1410 fathoms. A collection of over hundred species of Atlantic fishes is briefly dealt with by Mr. R. S. Clark (now acting as zoologist on Sir Ernest Shackleton's expedition), who also ports on half-a-dozen fresh-water fishes from Buenos Aires. Prof. W. A. Herdman describes the Tunicates, fifteen or sixteen species represented by about two hundred specimens. The only new species (Fungulus antarcticus) is a very remarkable form belonging to the deep-sea genus Fungulus, a single specimen of which was obtained by the Challenger in 1882, between the Cape of Good Hope and Kerguelen, from a depth of 1600 fathoms. Nearly 3000 miles away, but again in the far south and in very deep water (2485 fathoms), the Scotia species was obtained, and again but a single specimen. The limit of the Chordate sub-kingdom is found by many zoologists in the remarkable animals known as Pterobranchia, and the Scotia explorers were fortunate enough to secure numerous specimens of
a very interesting new species of Cephalodiscus, of which a fine account has been given by Drs. S. F. Harmer and W. G. Ridewood, whose previous studies of these strange types are well known. Thus we come, in the meantime, to the end of a valuable series of contributions to the marine zoology of the far south, contributions which do great credit to the investigators at home and to Dr. Bruce and his fellow-workers on the Scotia. We are told in the preface that there is material for six more volumes, and we hope that
the endowment of research, asks us to make it known that the article in the Evening News of August 2 dealing with this scheme was not written by him and that he does not identify himself with all the statements and opinions contained therein. A disclaimer was inserted in the same paper on August 5.
THE gold medal of the Company of Dyers has been awarded to Prof. A. G. Green, University of Leeds, and to Mr. W. Johnson, a research student of the University of Leeds, for research work in connection with the art of dyeing. The special research which
FIG. 2.-Ross Seal (Ommatophoca rossi) and Dr. Pirie on board the Scotia. these will see the light in brighter days. If they sustain the standard of what has been already published they will do well.
IT is stated in the Pharmaceutical Journal that, in consequence of the war, the meeting of the Austra lasian Association, which had been arranged to take place in Hobart in January next, has been postponed for a year, and that the Australasian Pharmaceutical Conference will not be held until January, 1917.
SIR A. SELBY-BIGGE (Permanent Secretary of the Board of Education since 1911) has been appointed special secretary to the committee of the Privy Council for the organisation and development of scientific and industrial research.
MR. F. W. HARBORD has been appointed honorary adviser in metallurgy to the Munitions Committee.
PROF. MELDOLA, writing as a member of the Advisory Council for the new Government scheme for
Report on the Scientific Results of the Voyage of s. y. Scotia." was the occasion of the award was an investigation into the constitution of aniline black.
THE Weber-Parkes prize of the Royal College of Physicians for 1915 has been awarded to Dr. Noel Dean Bardswell.
THE Paris Academy of Medicine has accepted the legacy of Dr. M. Sigaut of 8,000 francs, the interest of which will be used to establish a prize to be known as the Dr. Max Sigaut prize. The prize will be awarded every two years for the best memoir on early diagnosis and the best treatment in cancer of the digestive tract.
THE Secretary of State for the Colonies has appointed a committee to consider and report upon the present condition and the prospects of the West African trade in palm kernels and other edible and oil-producing nuts and seeds and to make recommendations for the promotion, in the United Kingdom, of the industries dependent thereon. The committee