68 



NATURE 



[May 17, 1900 



screw, the far end of the levers moves to and fro through 

 distances which can be controlled and measured. This end of 

 the levers carries a rod, and the diaphragm a small plate, both 

 of iridio- platinum ; if these two surfaces touch one another, a 

 flow of a small amount of electricity occurs, producing a sound 

 in a telephone held by the observer; at the same time he reads 

 by a telescope a graduated circular scale fixed on the screw. 

 Since the screw and levers can be moved at will by the 

 observer, he can, by this contact method, find the position of 

 the diaphragm, and follow its movements. Precautions against 

 vibrations are taken by having indiarubber suspensions, and 

 against temperature changes by covering the working parts with 

 boxes wrapped in felt. Movements as small as ^J^th of a wave- 

 length of sodium light have been measured by this apparatus. 



Mr. Killingworth Hedges exhibited jointing boxes and 

 aigrettes used in the rearrangement of the lightning conductors 

 of St. Paul's Cathedral. The original system for the protection 

 of the Cathedral from lightning was installed under the advice 

 of the Royal Society in about 1756. This was replaced in 

 1872 by what was then considered the most improved method, 

 when the unsoldered joints were found to be very defective ; in 

 some cases they were quite loose ; also the earths, originally 

 made by laying the cable in a drain which had become disused, 

 were in some cases insulated from the ground. New earths 

 have been substituted. The method adopted to protect the 

 structure unites the old system and the new cables to a hori- 

 zontal conductor run on the top of the parapet, entirely round 

 the building ; to this copper aigrettes as shown are teed at 

 intervals. 



Other electrical exhibits were models illustrating leakage from 

 electric tramways, shown by Mr. A. P. Trotter, and improved 

 forms of standard resistance coils made by the Cambridge 

 Scientific Instrument Co., Ltd. 



Dr. Isaac Roberts, F. R. S. , exhibited his magnificent volume of 

 photographs of stars, star-clusters and nebulae, recently reviewed 

 in Nature (vol. Ixi. p. 533). The volume contains seventy- 

 two photographs, which have been enlarged by mechanical 

 processes from the original negatives, and they furnish evidence 

 of the evolution of stellar systems from nebulous matter as seen in 

 the convolutions of spiral nebulae. They also furnish a founda- 

 tion for the inference that the system of the Milky Way is not 

 unlimited in extent, and that the numerous aggregations of 

 stars, seen in lines and curves in the stellar regions, indicate 

 their development from spiral nebuloe. 



Mr. Thomas Thorp exhibited some of his grating films and 

 their application to diflfraction colour photography, on Prof 

 Wood's principle. Dr. Downing, F.R.S., exhibited maps 

 illustrating the track of the total eclipse of the sun of May 28. 



Mr. W. A. Shenstone, F.R.S,, and Mr. H. G. Lacell showed 

 a quantity of non-splintering silica, suitable for use in the 

 oxy-gas flame. The method of converting this into tubes and 

 other forms of apparatus, as recently described in Nature 

 (May 3), was demonstrated practically, together with experi- 

 ments to illustrate the behaviour of vitreous silica under sudden 

 and great changes of temperature. The following apparatus, 

 constructed of silica, was also exhibited. A long tube for use 

 with a platinum thermometer ; a mercury thermometer ; bulbs 

 and stems for thermometers ; a Giessler tube ; a small distilling 

 tube ; and rods and tubes of various sizes for various purposes. 



Some examples of leadless glazed ware were shown by Dr. 

 T. E. Thorpe, F.R.S. 



Mr. H. B. Hartley and Mr. H. L. Bowman gave a de- 

 monstration of the properties of crystals yielding doubly-refracting 

 liquids on fusion. Certain crystalline organic compounds, viz. 

 /^-Azoxyanisol, /-Azoxyphenetol, and Cholesteryl benzoate, have 

 been found by Prof. Lehmann, of Carlsruhe, to give on melting 

 (at temperatures of 116°, 134° and 145° respectively) liquids 

 possessing the properties of double-refraction and dichroism, 

 even under conditions in which a state of strain is impossible. 

 When these anisotropic liquids are further heated, they change 

 at definite temperatures of transition (134°, 165° and 178° re- 

 spectively) into ordinary isotropic liquids. The intermediate 

 bodies have been called "liquid crystals," for, although the 

 evidence of their elasticity, viscosity, and dielectric capacity 

 shows them to be undoubtedly liquids, yet nevertheless they 

 possess, like crystals, both double refraction and dichroism., 



Specimens from the reefs of Funafuti were exhibited by 

 Prof. J. W. Judd, C.B., F.R.S., on behalf of the Coral-Reef 

 Committee of the Royal Society. The exhibits included :— 

 (l) Specimens illustrating the rate of growth of corals and 



NO. 1594, VOL. 62] 



calcareous algse from the reefs of Funafuti. Experiments made 

 by Mr. A. E. Finckh, of Sydney, who in 1898 carried the boring 

 made by Prof. T. E. David in the previous year from the depth 

 of 698 ft. to 1 1 14 ft., have thrown much new light upon this 

 important question. Specimens illustrating these experiments 

 are exhibited. (2) New and interesting forms of Foraminifera, 

 which have been described by Mr. F. Chapman. Thes6 

 include : — {a) Cycloclypens, a genus previously regarded as being; 

 very rare, but now shown to exist abundantly at Funafuti. The 

 two species formerly described are now shown to be dimorphic 

 forms of the same organism. \b) A curious form of Polytrema, 

 which occurs encrusting various objects in alternate layers with 

 the marine alga Lithothamnion, thus forming loose nodules. 

 {c) The newly- described Haddonia, first obtained from Torres 

 Straits, &c. 



Prof. H. G. Seeiey, F.R.S., showed drawings of restorations 

 of Dimorphodon. The drawings, of the natural size, are ba.sed 

 upon fossil remains from the Lias, in the British Museum. 

 They represent the skeleton as in the quadruped and biped 

 positions ; and show the contours of the body at rest, walking, 

 and preparing for flight, to illustrate proportions of the skeleton. 

 Dr. C. I. Forsyth- Major exhibited remains of extinct gigantic 

 and lesser lemurs from Madagascar, and living forms for com- 

 parison. Some beautiful examples of chalk fossils were exhibited 

 by Dr. Arthur W. Rowe. 



Dr. Manson exhibited longitudinal sections of filariated 

 mosquitoes {Culex ciliaris), showing that Filaria noctutna, 

 like the malaria parasite, leaves its mosquito host vi& the 

 proboscis. 



A collection of living marine worms (Annelids) from the 

 neighbourhood of Plymouth, designed to illustrate, as far as 

 possible, the prominent features in the habits of life of the 

 different types of this class of animals, and such modifications of 

 form as are related thereto, formed the exhibit of the Marine 

 Biological Association. 



Prof. E. Ray Lankester, F.R.S., on behalf of the Archaeo- 

 logical Survey of the Egypt Exploration Fund, showed repro- 

 ductions of paintings and sculptures in tombs of Ancient Egypt, 

 representing domestic and wild animals and birds. The tombs 

 of Ancient Egypt contain abundant representations of animal 

 life. In spite of the artists' ignorance of perspective and oc- 

 casional faulty colouring, the outlines are rendered with re- 

 markable fidelity to nature, often enabling the species to be 

 identified. Among domestic animals, the dogs are perhaps the 

 most interesting, as showing that extreme development of 

 various breeds had already taken place. The monuments from 

 which the drawings exhibited were copied are of two periods : — 

 (i) Tombs at Beni Hasan, of the Xllth Dynasty {ciixa 

 2000 B.C.); (2) the Tomb of Ptah-hetep at Saqqareh, of the 

 Vth Dynasty {circa 3000-2500 B.C.). 



Prof. A. C. Haddon, F.R.S., showed specimens illustrating 

 the decorative art of the Sea Dayaks of Sarawak. The carved 

 and painted designs of the Dayak men are entirely different 

 from the woven and embroidered patterns made by the women. 

 The former are chiefly plant derivatives, while the latter are 

 mainly greatly modified animal forms. The significance of the 

 distinction and thejreal meaning of the patterns themselves are not 

 yet elucidated. The method by which the women make the 

 patterns in their woven fabrics was also illustrated. The warp 

 is stretched on a frame, and numerous strands are tied tightly 

 with strips of leaves ; the whole is removed and then submerged 

 in a dye. The lashing is then undone, and the tied-up portions 

 are found to be undyed. The whole process is repeated if a 

 three-colour pattern is required. 



Ethnographical objects from Malay Peninsula (Malay and 

 Sakai) were shown by Mr. W. W. Skeat. The phonographic 

 records of songs of the Pangan tribe, a wild aboriginal tribe of 

 Negrito stock, received much attention. 



A collection of anthropometric instruments was shown by 

 Dr. J. G. Garson. 



The Royal Geographical Society exhibited a section cut from 

 the tree on Lake Bangweulu, Central Africa, under which 

 Livingstone's heart was buried, and containing the inscription 

 carved by his native followers. 



In the course of the evening, short discourses and demon- 

 strations were given by Sir Andrew Noble, K.C.B., F.R.S., on 

 modern explosives ; Dr. Arthur W. Rowe, on the photomicro- 

 graphy of chalk fossils by reflected light ; and Mr. F. Enock, 

 on photographs from living insects, showing the metamorphoses 

 of one of the Odonata. 



