82 



NATURE 



[May 24, 1900 



tone, simple in construction, and useful for a variety of 

 purposes. A feeble current of a few hundredths of an 

 ampere produces a tone that can be distinctly heard in 

 every part of a building, 204 x 114 feet, four stories high, 

 and containing ninety, rooms. It may also be used under 

 water. 



To photograph and thus record for analysis a sound of 

 any kind whatever, the resonator is removed by simply 

 screwing it off, without disturbing the sensitive plate ; 

 and a camera is substituted for the telescope and eye. 

 The window of the camera now forms the narrow slit, 

 and a lens, placed between the window and the refracto- 

 ineter, focuses a narrow, horizontal strip of interference 

 bands upon the photographic film. This film is wound 

 -about a cylinder (^ Raps, Wied. Ann. 1893, p. 194) kept 

 in rapid rotation by a small electric motor within the 

 camera. The speed of this motor is kept constant by 

 Lebedew's method ( W^zi?^. y?;?«. Band 59, p. 118). Con- 



NOTES. 



As we go to press, a message from Sir Norman Lockyer at 

 Santa Pola informs us that 130 volunteer observers have been 

 obtained from H.M.S. Theseus, the instruments have been 

 adjusted, and the Spanish authorities are assisting splendidly. 

 The weather prospects are good. 



Mr. J. S. BuDGETT left Liverpool on Saturday last on his 

 second expedition to the Gambia, where he is going in order 

 to complete his studies of the fish-fauna of that colony, and 

 especially to investigate the life -history and development of the 

 abnormal fishes Polypterus and Protopteriis. On reaching 

 Bathurst, Mr. Budgett will proceed up the River Gambia to his 

 former quarters on M'Carthy's Island, in the neighbourhood of 

 which he has already ascertained that these fishes are found 

 breeding during the rainy season. A memoir on some points in 



Quiet. 2. Fanning I. 3. Fanning II. 4. Noise. 5. Flageolet. 

 6. Fork Ci28- 7- i'ork C256. 8. Fork c'512. 9. Forks C+c. 10. Forks 

 C-t-c + c'. II. Forks g -fa. 12. Forks c-fe-t-g-fc'. 13. Tone source. 



Fig. 5.— Analyses of Fork Tones and Vowel Sounds 



(a)h. 2. (o)h. 3. p(oo)l. 4. (a)te. 5. m(ee)t. 6. s(e)t. 7. (a)t. 8. (i)t. 

 9. (au)ght. 10. (e)re. 11. (u)se. 12. (u)rn. 13. Fork C236. 



sequently the lateral vibration of the bands caused by 

 the sound, combined with the steady, vertical motion of 

 the exposed portion of the film, is recorded in parallel, 

 wavy lines. The shutter is opened for the time required 

 for a single rotation of the cylinder by an electrical 

 ■device. After each exposure the cylinder is moved in 

 the direction of its axis by turning a screw from without. 

 Thus a fresh portion of the film is brought under the 

 shutter, without stopping the motion or opening the 

 camera. In this way were taken the photographs of fork 

 tones and vowels here given (Fig. 5). The photograph of 

 a single tone from the source, whose intensity at the sensi- 

 tive plate has been determined by the first method, 

 affords a standard (viz. its amplitude) for determining 

 the absolute intensity of every other sound photographed ; 

 •while comparison with the wave-length appearing in the 

 photograph of the tone of a standard fork gives the pitch 

 •of other sounds. Benjamin F. Sharpe. 



NO. 1595, VOL. 62] 



the anatomy of Polypterus, based on specimens obtained by Mr. 

 Budgett during his first expedition, was read before the^ Zoo- 

 logical Society on May 8, and will shortly be published in the 

 Society's Transaclions. 



At a recent meeting of the British Ornithologists' Union and 

 Club, under the presidency of Mr. F. D. Godman, F.R.S., the 

 following resolution was unanimously adopted : — " That any 

 member of the union directly or indirectly responsible for the 

 destruction of nests, eggs, young or parent birds of any species 

 mentioned below should be visited with the severest censure of 

 the union and club." The birds referred to are the chough, 

 golden oriole, hoopoe, osprey, kite, white-tailed eagle, honey 

 buzzard, common buzzard, bittern and ruff. 



The committee of the Liverpool School of Tropical Diseases 

 have decided to despatch, at an early date, an expedition to the 

 Amazon to investigate yellow fever. The expedition will 



