August 29, 1878] 



NATURE 



407 



up as to determine the general laws of distribution for comparison 

 witli those obtaining in the animal kingdom. After some con- 

 sultation with Sir J. D. Hooker, and other botanist?, it was 

 decided to make the Kew herbarium the basis of an enumeration 

 of all the plants hitherto found in the countries lying between 

 Panama and the territories of the United States. The principal 

 reason that led to this decision was the fact that the vast collec- 

 tions at Kew have recently been carefully studied for Messrs. 

 Bentham and Hooker's "Genera Plantarum," and for various 

 other publications, so that as far as generic types are concerned, 

 Kew herbarium is perfectly available and reliable for the object 

 in view. To this will be added all the species published, but not 

 represented at Kew by named specimens, and the novelties con- 

 tained in the collections made by the French Scientific Commis- 

 sion. The enumeration will be supplemented by references, 

 localities, altitudes, and everything that will be useful in drawing 

 np an essay on the distribution, &c., of the plants. Although it 

 was impossible to undertake a critical examination of all the 

 species, a considerable number of interesting and apparently new 

 species will be described, and many of them figured, from 

 drawings by Fitch, and coloured drawings done on the spot by 

 Mrs. Salvin. 



The valuable collection made by the Brothers von Schlagint- 

 weit during their extensive journeys through India and Thibet is 

 aow arranged for exhibition in the royal castle at Nuremberg. 

 It forms one of the most extensive collections ever brought from 

 the East, and possesses objects of rare value, especially for 

 anthropology. Among these might be mentioned the plastic 

 representations of Indian races, numbering 275 specimens, pre- 

 pared from casts taken from living individuals, and carefully 

 arranged according to castes and races. A large variety of 

 skulls from different regions in India will also prove of no small 

 use to the growing number of students of cranial development. 



We notice the death at Paris of M. J. Fordos, a well-known 

 French chemist, and vice-president of the Paris Chemical Society. 

 His name is chiefly known in connection with researches on thio- 

 acids, and numerous derivatives of sulphur, ligneous colouring 

 matters, estimation of morphium, and several technical subjects, 

 especially the manufacture of cyanides and ferro-cyanides. 



Prof. Suess, the well-known Vienna geologist, is at present 

 traversing Italy with a; number of his students, engaged in a 

 geological study of the peninsula. The journey includes Vesuvius 

 and Etna. 



The additions to the Zoological Society's Gardens during the 

 past week include a Prairie Wolf (Cams latrans) from the Rocky 

 Mountains, North America, presented by Prof. M. C. Vincent, 

 F.G.S., F.R.G.S. ; a Common Jackal {Cants aureus) from 

 India, presented by Mr. J. Smith ; a Spotted Ichneumon [ffer- 

 pestes auropunctatus) from Nepal, presented by Mr. W. Pyne ; a 

 Bronze Fruit Pigeon (Carpophaga cened) from India, presented 

 by Mr. A. H. Jamrach; a White-eared Bulbul (Pycnonotus 

 hucotis) from North- West India, presented by Mr. W. Woolner; 

 a Black Saki {Pithecia satanas) from the Lower Amazons, 

 deposited. 



THE BRITISH ASSOCIATION 

 REPORTS. 



Report of the Committee for Commencing Secular Experiments 

 fin the Elasticity of Wires, by J. T. Bottomley. — The Committee 

 have to report that the arrangements for suspending the wires 

 for secular experiments on elasticity are now complete, and that 

 within the last few days two wires, one of palladiuni and the 

 other of platinum, have been suspended in their places. 



An iron tube has been erected in one of the rooms in the 

 tower of the University Buildings in Glasgow. It is 60 feet 

 long, 9 inches wide, and 4^ inches deep from face to back. It 

 is of rectangular section, in lengths of 6 feet, and it is sup- 



ported by being firmly attached to the heavy outer stone wall of 

 the tower. 



At the top of the tube there is a heavy gun-metal plate which 

 is supported independently of the iron tube ; and from this 

 plate the wires under examination are to be suspended, as well 

 as additional wires to be used for carrying additional comparison 

 marks. With this arrangement no yielding of the supporting 

 plate that may take place will introduce errors into the results of 

 measurement of the lengths of the wires ; for the point of support 

 of the wire carrying comparison marks will experience the same 

 amount of lowering, due to the yielding, as is experienced by 

 the wire to be measured against these marks. The gun-metal 

 plate has been pierced with three rows of holes, through which 

 the wires are to pass. The holes are trumpeted at each end, so 

 as to avoid sharp contact with the wires ; and the rows are 

 arranged so that the wires shall hang down in their planes 

 parallel to the face of the tube. It has not yet been decided 

 what is the best way of fixing the upper ends of the wires above 

 the gun-metal plate, or of attaching the weights to their lower 

 ends. No thoroughly satisfactory mode of attachment has yet 

 been found. In the course of experiments to be referred to 

 immediately, which have been carried on at Glasgow on the 

 breaking weight, and the Young's Modulus of Elasticity of the 

 gold, platinum, and palladium wires, which, it is intended, 

 shall be first suspended for examination, several modes of sus- 

 pension have been tried ; but it has not been found possible to 

 make sure of avoiding very considerable weakening of the wire 

 at the points of attachment at the ends. 



At the bottom of the iron tube there is a window of plate 

 glass through which the lower parts of the wires can be viewed, 

 and the window can be drawn up so as to allow of the lower 

 parts of the wires being reached. 



In front of the window a strong gun-metal table is set up. 

 It is supported independently of the iron tube and of the floor 

 of the room, on iron brackets fixed to the stone wall of the 

 chamber, and is very carefully levelled. On this table a cathe- 

 tometer is carried, by means of which marks on the wires are to 

 be observed. The cathetometer moves on the table parallel to 

 the planes of the rows of wires. It has the two back feet of 

 the triangular sole plate on which it is supported movable in a 

 V-groove cut in the table, the third foot resting on the plane 

 upper surface. There is also a slot cut in the table through 

 which a screw passes up from below to the sole plate of the 

 cathetometer, and by means of this screw the cathetometer can 

 be clamped in any required place. 



The cathetometer is a small instrument which has been con- 

 structed by Mr. James White of Glasgow for the purpose of 

 these experiments. The main pillar is one foot high. It is 

 supported on a sole plate having three levelling screws. The 

 telescope or microscope, having cross -fibres, is raised or lowered 

 on this pillar on a proper geometrical slide, and has also a lifting 

 screw in connection with a vernier for giving fine adjustment. 

 The vertical pillar is carefully graduated ; and by means of this 

 scale the differences of levels of proper marks put upon the 

 wires are to be determined. 



The arrangements have only been completed within the last 

 few days. They require to be carefully tested in several points, 

 and particularly the cathetometer requires careful examination. 

 There is every reason, however, to expect that the work will 

 turn out quite satisfactory. As soon as possible the work of 

 testing will be completed and wires suspended, measiured and 

 marked. 



During the past year experiments in connection with this in- 

 vestigation have been carried an in the laboratory of the Uni- 

 versity of Glasgow on the breaking weights and elastic properties 

 of various wires. In the first place the breaking weights and 

 the Young's modulus, or modulus of elasticity for longitudinal 

 pull, have been determined for the gold, platinum, and palladium 

 wire with which it is proposed that the secular experiments on 

 elasticity shall commence. A large number of experiments on 

 the effect of stress, maintained for a considerable time, in alter- 

 ing the breaking weight and the extension under increased stress 

 of various wires, have been carried on. Soft iron wire, steel 

 wire, and tin wire in particular, have been experimented upon, 

 and already some interesting results have been obtained, showing 

 that prolonged application of stress certainly produces a notice- 

 able effect. 



Numbers showing the nature of the results already arrived at 

 are appended ; but the whole subject still requires much careful 

 examination. 



