Sept. 1 8, 1879] 



NATVRE 



483 



fusion must be a constant number for all solids. As the lengths 

 of oscillation of the molecules of a body are measured by the 

 coefficient of expansion, we see that the result is the same as 

 that reached some time since by M, de Heen, and which is now 

 extended to liquids. 



In a series of experiments recently described to the Vienna 

 Academy, Prof, von Waltenhofen has sought to deduce from a 

 direct measurement of the work done in induction of an electric 

 current in a closed circuit of given resistance, the mechanical 

 equivalent of heat. For induction, a magneto-electric machine 

 was used, whose electromotive force was ascertained to be pro- 

 portional to the number of revolutions. A dynamometric handle 

 of the newest construction was attached, and it was furnished 

 with an arrangement for receiving the work-diagrams. The 

 induced currents were measured by means of a tangent galvano- 

 meter. The results were found to be in satisfactory agreement 

 with Joule's equivalent. 



An interesting communication relating to the photography of 

 spectra has recently been made to the Berlin Academy of 

 Sciences by Ilerr H. W. Vogel. It is not very difficult to pho- 

 tograph the spectra of incandescent gases if the source of light 

 is an induction spark which is produced by a current with an 

 inserted Leyden jar. The photography of the much fainter 

 spectra obtained by the simple induction-spark presents far more 

 considerable difficulties, and these are the very ones which Herr 

 Vogel has now completely mastered by the employment of so- 

 called gelatine-dry-plates. These plates are remarkable for their 

 extreme sensitiveness, which Herr Vogel has estimated to be at 

 least fifteen times that of the ordinary wet plates. They keep 

 good for years, it seems, and are already obtainable in the trade. 

 By using them Herr Vogel succeeded in fixing the spectra of the 

 little oxygen tubes prepared and studied by Herr Paalzow, 

 thus rendering lines visible in the more refrangible part of the 

 spectrum which cannot be observed by direct vision. The two 

 gentlemen are now engaged in studying these spectra more 

 minutely in company, and will doubtless soon publish the results 

 of their researches. 



A VIOLENT shock of earthquake, lasting forty seconds, is re- 

 ported from the island of St. Thomas (West Indies). It occurred 

 on July 30 at 11. 35 a.m. 



The Temps publishes a letter from M. Francis Laur, a mining 

 engineer, complaining that the French Parliamentary Commission 

 appointed for preventing the effects of fire-damp, has given no 

 sign of life, although a credit of <p,ooa francs was assigned to it, 

 and more than fifty inventors have sent in instruments or methods 

 for examination. 



M. Ferry, Minister of Public Instruction, has published an 

 official circular for the better organisation of the bursaries granted 

 after examination to students taking their degrees in the several 

 French universities. These bursaries are of quite recent founda- 

 tion and present a strong similarity to the sizarships or scholar- 

 ships in the English universities. 



A.MONGsr European countries there are two where science has 

 been dreadfully neglected up to the present time. For one of 

 these two, viz., Turkey, we are afraid there is not much hope of 

 reformation, at least in its present condition. It is satisfactory, 

 however, that the other one, viz., Spain, seems at last to be awak- 

 ing from its lethargy with regard to science. Some time ago we 

 had occasion to refer to a commendable Cronica eienlifica, pub- 

 lished annually in two volumes, by Dr. Emilio Huelin, of 

 Madrid. Another publication which appears monthly, the 

 Revista contemporanea, of which Dr. Francisco de Asis Pacheco 

 IS the editor, has just come under our notice. The last number 

 of this serial contains an excellent article on the sciences in 1879, 

 by Ricardo Becerro y Bengoa, giving a most elaborate account 



of the work done recently in all branches of science. The pub- 

 lishers are Seiiores Perojo Hermanos, of Madrid, who also 

 publish La Naturaleza, an illustrated science review, in two 

 volumes annually. 



The project of building a canal from Amsterdam to the Rhine 

 (in continuation of the new canal between that city and the 

 German Ocean) has lately been again brought before the Dutch 

 Government. Our readers are aware that the project is not new, 

 and it is easy to see the great advantages its execution would 

 bring to the commerce of Holland generally and of Amsterdam 

 in particular. 



At a recent meeting of the United States Anthropological 

 Society, Mr. F. H. Gushing, who has made an original and ex- 

 perimental study of aboriginal processes in the manufacture of 

 pottery, stone axes, and flint arrow-heads, using only the tools 

 which were within the reach of the aboriginal manufacturers, 

 gave an interesting description of the manner in which flint im- 

 plements, especially arrow- and spear-hcads, were made by the 

 prehistoric inhabitants of this country and Europe, previous to 

 the discovery or introduction of iron. It is the popular impres- 

 sion that flint arrow-heads were all chipped into shape by strik- 

 ing off fragments with a rude stone hammer, and this was the 

 method first tried by Mr. Gushing. He found, however, that it 

 was impossible to imitate in this way any of the finer and more 

 delicate specimens of Indian arrows, and that three out of four 

 even of the coarser forms were broken in the process of manu- 

 facture. It was evident, therefore, that the Indians had other 

 and more delicate processes. After many unsuccessful experi- 

 ments, he accidentally discovered that small fragments could be 

 broken off from a piece of flint with much greater certainty and 

 precision, by pressure with a pointed rod of bone or horn, than 

 by blows with a hammer-stone. The sharp edge of the flint 

 would cut slightly into the bone, and when the latter was twisted 

 suddenly upward a flake would fly off from the point where the 

 pressure was applied in a direction which could be foreseen and 

 controlled. To this process Mr. Gushing gives the name of 

 flaking, to distinguish it from chipping produced by percussion. 

 And its discovery, he considers, removes most of the difficulties 

 which previous experimenters had met with in trying to work 

 flint without the use of iron. Spear- and arrow-heads could in 

 this way be flaked even into the most delicate and apparently 

 fragile shapes with a certainty attainable in no other way, and 

 with a greatly-lessened probability of breakage. Mr. Gushing 

 then described, with the aid of blackboard illustrations, aU the 

 steps in tlie manufacture of an arrow, beginning with the striking 

 off of a suitable flake from the mass of material selected, trimming 

 it roughly with a pebble into a leaf -shape with a bevelled edge, 

 scaling off surface flakes by repeated blows with a hammer-stone 

 upon this edge at right angles to its plane, and finally finishing, 

 pointing, and notching the arrow-head with the bone flaking- 

 instrument previously referred to. 



The Russian Foreign Ministry has just published a very good 

 Russian and Ghinese dictionary, by the first translator of the 

 Russian mission at Pekin, M. P. S. Popoff. The work is printed 

 by a new kind of autography devised by M. Alisoff. 



M. Ferry has published an order for the appointment of 

 librarians in the establishments of the University. No one is to 

 be appointed except after two years' trial and passing successfully 

 a professional examination. This is to consist of a French dis- 

 sertation on a given subject of bibliography, and the classification 

 of fifteen works treating of different matters, and t)elonging to 

 several periods of the history of the art of printing. 



The Musce Scolaire, which had been removed by the Minister 

 of Public Instruction to one of the halls of the Palais Bourbon, 

 is to resume its former situation. The hall in which it had been 

 located is wanted by the questors for the installation of the 



