June 23, 1921] 



NATURE 



537 



graphic transparencies (Metallurgical Department). 

 Photomicrographs, shown as enlarged transparencies, 

 illustrating recent work relating to the constitution 

 of various alloys of. aluminium. They show typical 

 structures found in the alloys of aluminium with 

 magnesium, copper, silicon, iron, and zinc when 

 treated in various ways. Some illustrate particularly 

 the method of determining the temperature at which 

 the allovs become completely solid by quenching small 

 specimens from various temperatures. The presence 

 of liquid at the moment of quenching makes itself 

 felt by a characteristic fine micro-structure. 



The Cambridge and Paul Instrument Co., Ltd. : 

 Darwin-Hill mirror position-finder. This instrument 

 enables the position of an object moving in the air 

 to be accurately recorded in terms of three rectangular 

 co-ordinates. Two horizontal mirrors ruled in squares 

 are placed one at each end of a common base line, 

 the rulings being parallel and perpendicular to the 

 base line. The object is observed through a fixed, but 

 adjustable, aperture sight, and the position of the 

 image in each mirror is tnarked on the glass surface 

 either continuously or at simultaneous times controlled 

 by telephone or signal. Each mirror gives two co- 

 ordinates for any position of the image, from which 

 the three co-ordinates of the object can be calculated 

 for successive positions. These instruments have been 

 used for the observation of high-angle gun-fire for the 

 preparation of range tables, for checking anti-aircraft 

 gun-fire, and for recording the flight of experimental 

 aircraft, pilot-balloons, etc. 



The Science Museum : Gravity torsion balance. 

 This instrument was designed by Baron R. Eotvos, 

 professor of physics at the University of Budapest, in 

 order to determine the variation of gravity over com- 

 parativelv short distances, and to make experimental 

 investigations on the form of the earth. The instru- 

 ment has also been used in Hungary for the location 

 of mineral deposits when the density of the mineral 

 differed considerably from that of the surrounding 

 strata. 



Radiological Branch, Research Department, Royal 

 Arsenal, Woolwich : Pinhole photographs of the 

 Coolidge radiator tube and photographs illustrating 

 protection in the X-ray examination of materials, 

 (i) Pinhole photographs illustrating the change in 

 shape of the focal spot with current change. 

 (2) Photographs illustrating the various parts of the 

 target of the above tube which emit X-rays under 

 varj'ing conditions. (3) Photographs illustrating 

 X-rav protection when radiographing large metal 

 objects. (4) Photographs illustrating portable set de- 

 signed and made in the Research Department, Wool- 

 wich, with complete protection, for visual examina- 

 tion of materials. 



Instrument Department, Air Ministry: (i) Mercury 

 barometer for use on airships. (2) DifTerential 

 thermometer for airships. (3) Twin-pointer revolu- 

 tion indicator. (4) Gyroscopic turning indicator. 

 (5) Aneroid altimeter with computer dial. (6) Per- 

 meameter. (7) Liquid oxygen vaporiser 



Mr. A. Leslie Armstrong: Engravings upon flint- 

 ciTjst discovered at Grimes Graves, Norfolk, together 

 V. ith flint implements, upon an ancient living level 



3 ft. beneath the present surface. The most important 

 engraving is a wonderfully likelife drawing of a stag, 

 or perhaps an elk, evidently disturbed whilst brows- 

 ing. One foreleg is raised, the others are buried in 

 herbage. The head is held erect and stalks of grass 

 are shown hanging from its mouth. A second en- 

 graved piece has a well-drawn animal's head upon it, 

 apparently that of a hind. Others bear lines and 

 irregular forms on them. .AH were discovered in 

 September last by the exhibitor upon an ancient living 

 level upon glacial sand 3 ft. beneath the present sur- 

 face, associated with flint implements of Mousterian 

 type, bone tools, and potterj\ 



British Museum (Xatural History) : Fading of 

 museum specimens exposed to light (Sir Sidney 

 Harmer). The object of the experiments was to test 

 the efficacy of "antifade " glasses in protecting speci- 

 mens from fading. The conclusions reached are 

 (i) that specimens kept in the dark do not fade when 

 subjected to a considerable rise of temperature ; 

 (2) that objects exposed to direct sunlight are bleached 

 even if protected by "antifade" glass; (3) that the 

 injurious action of either diffused daylight or strong 

 electric light is far less than that of direct sunlight; 

 and (4) that "antifade " glasses may have some slight 

 advantage in protecting specimens from the bleaching 

 effect of diffused daylight or of electric light. 



Department of Geology, British Museum (Natural 

 History) : .An ancient human skull from the Trans- 

 vaal (.Mr. VV. P. Pycraft). Towards the end of 1913 

 a human skull-cap and temporal bone, and a few 

 other skeleton fragments, apparently of considerable 

 antiquity, were found at Boskop, in the Potchefstroom 

 district of the Transvaal. The skull-cap is remark- 

 able for its great length and parietal width — length 



205 mm 



narrow. 



cephalic. 



breadth 150 mm. — while the forehead is 

 The skull is dolichocephalic and, tapeino- 

 The auricular height could scarcelv have 

 exceeded 125 mm., and from this it may be assumed 

 that the cranial capacity did not exceed 1700 c.c. 

 The precise affinities and geological age of this skull 

 are matters now under investigation. 



Department of Zoology and Comparative Anatomy, 

 University College : Cytological preparations. — (a) 

 Golgi apparatus ; (b) polar body, Ornithorhynchus 

 eggj and (c) Anello cromatico, Dytiscus (Dr. Gatenby). 



Dr. C. T. Trechmann : Shell of the recent Pleuro- 

 tomaria (P. Adansoniana) dredged off Barbados, West 

 Indies, in 60 fathoms of water Pleurotomaria is a 

 " living fossil " ; possibly only about five specimens 

 of this species are known. Other species occur off 

 Japan. 



Zoological Laboratory , Imperial College of Science, 

 South Kensington, S.W.: Effect of pineal gland ad- 

 ministration on amphibian melanoohores (Dr. L. T. 

 Hogben). Administration of fresh gland or pineal 

 extract causes contraction of the melanophores. This 

 eff^ect first appears after a previous treatment of ten 

 days with tri-weekly administration, and follows each 

 subsequent treatment lasting for six hours and at- 

 taining maximum contraction in half an hour. Tad- 

 poles become exceedingly pale and quite transparent 

 in the head region when under treatment while the 

 effect lasts. 



The South- Eastern Union of Scientific Societies. 



T' 



'HE twenty-sixth annual congress of the South- 

 Eastern Union of Scientific Societies was held 

 at Reading on June 8-1 1, under the presidency of 

 Prof. E. B. Poulton, who, in his presidential address 

 on 'The Inspiration of the Unknown," showed that 

 entomology was a world in which many workers 

 wet'e still needed, and that great blanks in knowledge 

 NO. 2 69 5 1 VOL. 107] 



still required filling up. Dr. Dukinfield Scott con- 

 tributed a paper on ''The Earliest Land Flora," and 

 brought under notice the work of Kidston and Lang 

 on the Lower Devonian flora, and illustrated by the 

 lantern the structure of Psilophyton, a genus founded 

 by Dawson and only now at last coming to be 

 generally accepted by palaeobotanists. Miss G. Lister 



