Feb. 19, 1874] 



NATURE 



303 



an impurity ; it is quite sufficient to Ivnovv that an agreement in 

 lengili of organ-pipe and aerial wave-length was assumed which 

 does no; exist, and that, moreover, the meclianical nature of the 

 organ-pipe, and its delicate apparatus so wonderfully balanced 

 ■for the attainment of its ends, had escaped observation. The 

 admirable method of expiriment for ascertaining the velocity of 

 sound in gases, devised by M. Kundt, by means of glas; tubes 

 and lycopodium seed, is free from the same source of error ; 

 and, as might be anticipated, comparison shows a marked diffe- 

 rence in estimates. In respect of carbanic acid gas and hydro- 

 gen gas, for instance, Dulong differs from Kundt, his estimate 

 in the one case being less by one-fifth of the whole, and the 

 other more by one-fourth ; the divergence interprets itself, indi- 

 cating the relation of their densities to the compelling force, the 

 unseen mechanical action at the mouth of the organ-pipe. This 

 will be clear when the " air-moulded reed '' is fully understood 

 in its nature and functions. When the magnetism of the earth 

 is perceived, the dip of the needle to the north or south of the 

 equator in accord with its localisation is explained. 



The confession of "obscurity" amounts to a concession that 

 the old theory has been found wanting, that it is inadequate to 

 deal with facts. Whether in dealing with the larger questions 

 here brought into discussion, or with the simpler class, the mere 

 modifications of structure, it is equally incapable. If, for in- 

 stance, a stopped pipe is pierced through the stopper and a short 

 open pipe inserted, say a third or fourtli the diameter and a 

 third or fourth tlie length, what will be the effect of this on the 

 pitch ? The old theory would reply, the added length would 

 cause a flattening of pitch, and then will come a proviso for 

 safety's sake, that if the change converted it into an open 

 organ pipe then the pitch would be raised in accordance with the 

 open length . We go to Nature for her say in the matter, and find 

 that the pitch is raised not flattened, and that the extent is about 

 a quarter of a tone, and that further lengthening of the smaller 

 pipe takes back the pitch agam just its quarter tone. If an- 

 other stopped pipe is drilled at the back with a hole of a diameter 

 a third or fourth of that of the pipe, but so thit it shall be at a 

 higher level than the lip or edge of the mouth, in effect short- 

 ening the air column by admission of external air at a higher 

 point, what wdl be the result? On the old theory we should 

 expect the pitch to be higher in consequence. Appealing to the 

 ear we know that, on the contrary, it is flattened. Tliese re- 

 sults cease to be anomalies when viewed under the new theory, 

 and indeed they would be predicted with confidence as the 

 necessary outcome of the conditions. 



The proposition that in an organ-pipe there is no constant 

 wave-length for an ascertained pitch, will no doubt be discoun- 

 tenanced as novel and revolutionary, but it is true and will have 

 to be acknowledged. A further proposition that in an open 

 organ-pipe there are three different velocities speeding at dif- 

 ferent rates, concurring in every vibration, and essential to the 

 synchronic time of its note, has a still more aggressive aspect 

 defiant of law. Not so. It is because law — "known law," 

 does not cover the facts, is unstable in its applications, and is 

 deficient in prevision, that there is room for new hypothesis 

 which does not play fast and loose with nature ; the utmost 

 exactitude of length in an organ-pipe is as indispensable in this 

 as in the older theory, but the relation is one of proportion to a 

 system, and the least and every variation will make imperative 

 suitable or corresponding modifications in other portions of the 

 structure. Only a whistle, yet with more to marvel at for deli- 

 cacy of organi ation and beauty of adaptation " than is dreamt of 

 in philosophy." 



As regards " fixity of wave-length," that characteristic re- 

 appears in a new relation, and we shall find that, allowing for 

 retardation by friction, the super-nodal half-wave of the pipe 

 corresponds very closely with length in atmosphere. The cause 

 of the displacement of the node is involved in the physical action 

 taking place at the mouth of organ pipes, the consideration of 

 which is reserved for a further communication. 



Hermann Smith 



Auroral Display 



As a few remarks on the aurora ol the 4th may be of interest 

 to some of your meteorological readers I append the following 

 notes : — 



At 6.15 P.M. on Wednesday, the 4th inst., an aurora com- 

 menced in the northern part of the sky which gradually went 

 down towards the south. 



7. 15.— Semicircle from W. to E., streamers shooting up from 



7.25.— Light more diffused, a few streamers at N.W. 



7.30.— A semicircle of diffused lisjht from W.S.VV. to E. 



7.35.— Bright line of light from W S. \V. to E. ; no streamers. 



7.40.— A very faint irregular line of light from W.S.VV. to li. 



7.45.— Diffused light. 



7.50. — Same as at 7.45. 



7.55. — Streamers shooting down from zenith all round. Very 

 fine. 



8.— Bright at N.N. E. Streamers N. and N.N.E. A sharp 

 S.E. breeze. 



8.5.— Bright light at N.W. No streamers. 



8.10. — Streamers at N.E. 



S. 15. —Streamers at S.S.E. 



9' — No aurora perceptible. 



From the above, we note one peculiarity, namely, that the 

 aurora was chiefly in W. + E. or W.S.VV. and S.S.E. 



Willi A.M II y. Watson 



Braystones, near Whitehaven, Feb. 9 



[We have received letters concerning this aurora from several 

 other parts of the country. ] 



THE PHOTOGRAPHIC SOCIETY 



A LTHOUGH we published last week a letter from 

 -'*• Mr. Baden Pritchard, Hon. Sec. of the Photographic 

 Society, impugning the justice or accuracy of oar stric- 

 tures on that Society, our esteemed correspondent has 

 not caused us to change our opinion. 



We have now before us the Journal of the Society for 

 the past year (a summer vacation of three months ex- 

 cepted), and certainly it fLirnishes/r/wi? /<;«'<• evidence of 

 the most apathetic and inefficient condition which is con- 

 sistent with continuous e.xistence. The numbers contain 

 eight pages each, the page little more than half the size 

 of that of Nature, and in the whole year's proceedings 

 there are twelve pages devoted to science, half of this 

 being a lecture by Prof. Stokes ; three or four papers of 

 considerable value on technical points of photographic 

 interest, and much which the charity of any semi-learned 

 society would be largely strained in giving paper and 

 ink to. 



There is no mention of scientific or other committees, 

 no provision for them in the laws, no reports of investiga- 

 tions made or to be made, no notice of scientific discovery 

 abroad or recognition of discovery at home. Mr, Pritchard 

 has no need to assure us that the body " does not profess 

 to be a purely scientific one" — the scientific element in it, 

 so far as its own record shows, is purely fortuitous. 



But without demanding scientific labours from a body 

 not " purely scientific," we do not even find evidence of 

 common activity in the research of practical problems, 

 and if any of its members are, as Mr. Pritchard suggests, 

 engaged in researches on the process and nature of film 

 best suited for transit of Venus observations, they have 

 not had faith enough in the countenance of their Society 

 to place their labours before it, or ask its assistance in 

 performing them. 



Since our article appeared, the revolution alhided 

 to has taken place, and that part of the Society in 

 favour of reform having a majority at the meeting ap- 

 pointed for the discussion of the question, have carried 

 an amendment to the laws providing that henceforward 

 the Society at large shall select its council, and that the 

 majority of the actual council shall not have the power to se- 

 lect for retirement such members as it sees fit and to decide 

 who shall replace them, as has actually been the case 

 hitherto ; it has also been decided that the presidency 

 shall rotate. These measures were, as we learn from the 

 photographic papers, strongly opposed by the council, and 

 upon being carried by a majority of 30 to 23 (the council 

 itself voting in the minority) the entire body resigned. 



As the meeting at which this stroke of singular policy 

 was made, was that for the election of the new mem- 

 bers of council, these were enabled to assume the 

 reins of government and prevent the, otherwise in- 



