i6o 



NA TURE 



[June i8, 1896 



loops is there jjiven. Tliis was the first case in wliich it had 

 been found possible to express the integral 



/• Adz 



algebraically, where Z = (l -2') (/^ - zf-- A-, and A and h are 

 constants. The accompanying diagram is for the next possible 

 case of seven loops, and has been made by Mr. T. I. Dewar. 

 The circle in the lower hemisphere shows where the pressure 

 of the chain on the sphere becomes zero ; below that, the 



obtain the solid effects with this instrument. The lenses may 

 be angled, and moved to and from the centre at will. .■\lso the 

 distance can be varied between the picture and the lenses. The 

 distance between picture and lenses is greater than usual, to 

 allow a wider mirror, which is advantageous. 



A number of cloud photographs taken in different parts of the 

 ocean world were exhibited by Captain D. Wilson- Barker ; and 

 Mr. F. H. Worsley-Benison exhibited a series of seascape photo- 

 graphs. The photographs were enlargements in carbon. The 

 whole picture in each subject was the result of one exposure only. 



chain is supposed to rest on the interior of the hollow sphere. The 

 tesselated pavement indicates the position of the directrix plane. 

 The tension at any point of the catenary is the same as in a 

 chain hanging vertically to this plane, like a similar property in 

 the plane catenary. A great many other cases with different 

 numbers of loops have been examined, but the results turn out 

 to be imaginary 



Mr. Robert L. Mond exhibited the following apparatus in- 

 tended for the Davy- Faraday Research Laboratory of the Royal 

 Institution; (l) Kilogram automatic balance (Rueprecht, 

 Vienna). (2) Prism automatic spectroscope (Kruss, Hamburg). 

 (3) i-inch spectrometer after Landolt and Briihl (Hildebrandt, 

 Freiberg!. (4) Hiifner photo-spectrometer (Albrecht, Tubingen). 

 (5) Large polariscope 6-inch Landolt. (6) Small Landolt polari- 

 .scope {Schmidt and Haensch). (7) Berthelot platinum bomb 

 (Golaz, Paris). (S) Glass scale cathetometer (R. Fuess, Berlin). 

 (9) Petrographical microscope (R. Fuess, Berlin). (10) Millivolt 

 meter reading Centigrade degrees for Le Chatelier Thermophile 

 (Keiser and Schmidt, Berlin). (11) Compensation box of 

 Physikalische Reichsanstalt, Berlin (Wolff, Berlin). (12) Set of 

 standard resistances (Wolff). 



Prof Dewar showed a portable apparatus for the production 

 of liquid air and oxygen. A working model of support for large 

 specula, designed to leave the line of collimation undisturbed, 

 was exhibited by Dr. G. Johnstone Stoney. 



Mr. F. McClean exhibited (l) photographic stellar spectra of 

 Type IIL, including spectra of o Cetus (showing bright lines 

 II7 and H8), a Taurus, o Orion, a Scor|>io, 5 Andromeda, a 

 Cetus, S Ophiuchus, ,ci Gemini, 5 Virgo, 6 Pegasus, a Hercules. 

 (2) Photographic spectrum of Secchi's Type IV. This was a 

 spectrum of the star 152 Schjellerup (5^ magnitude), compared 

 with spectrum of o Orion. (3) Series of photographic spectra 

 of the variable star 8 Lyra, compared with spectra of 3 Orion 

 and 5 Taurus. 



A new form of stereoscope was .shown by Sir David L. Salo- 

 mons. This stereoscope has been designed to suit the vision of 

 all persons, without straining the eyes. Many individuals who 

 are unable to use the ordinary stereoscope have been able to 



NO. 1390, VOL. 54] 



Coming now to natural science : Models of the flowers of 

 Aristoloihia ^gas from Brazil, and of Sfafc/ia gigantca from 

 Natal (made by Miss Emelt for the Museums of the Royal 

 Gardens, Kew) were exhibited by the Director, Royal Gardens, 

 Kew. Flowers with livid colouring and exhaling indol or .some 

 allied body occur in different families of the vegetable kingdom. 

 Kerner (" Natural History of Plants," translated by F. Oliver, 

 vol. ii. pp. 197-200) thus describes ihem : " Flowers provided 

 with indoloid scents resemble animal corpses in their colouring, 

 having usually livid spots, violet streaks and red-brown veins on 

 a greenish or fawn-coloured background." " Such flowers . . . 

 are always visited by carrion-flies or dung-bettles in abund- 

 ance." 



The Director of the Royal Gardens also show'ed photographs 

 of Hrematozoa of fly disease of South Africa (exhibited or> 

 behalf of the Government of Natal). For the last half century 

 the T.setse-fly has been notorious as a terrible scourge to live- 

 stock, and the most formidable of impediments to colonisation 

 in Equatorial and South Africa. Surgeon-Major Bruce has now 

 discovered that the fly is itself innocuous, and is only fatal to 

 animals when it is the carrier of a flagellated infusorian {/uTi/ia- 

 lozoon) which it introduces into their blood. 



Two coloured casts of the New Zealand lizard, Hatteria or 

 Sphenodon, were exhibited by Prof Ray Lankester. The casts- 

 were taken at the Zoological Society's Gardens from a full- 

 grown specimen immediately after death, and painted by Prof 

 Lankester, so as to give the natural colours. Stuft'ed specimens 

 of lizards' skins are verydifticult to prepare with .iny approach to 

 natural form and folding of the skin. Such casts as those shown 

 are useful as preserving form and pose. 



Mr. Frederick James exhibited examples of British Lepidop- 

 tera {Rhopaloccra) denuded of scales to illustrate their neuration. 

 In each specimen the scaleless left fore and hind wings illustrated 

 the neuration of the genus. 



An experiment to ascertain the period at which larva; are 

 sensitive to surrounding colours, formed the subject of an exhibit 

 by Prof Poulton. The larvae of Ainphidasis hctularia were, 

 after hatching, surrounded w ith green leaves and shoots. During 



