February 5, 1892.] 



SCIENCE. 



75 



the United States, is described. A large wheel, fixed at a certain 

 distance from the bank, is put in motion by the current. The 

 blades of this wheel are provided with a network of iron wire in 

 tended to raise from the water any large object coming in contact 

 with them. A sort of bar-work starting from the wheel is so 

 placed as to increase the strength of the current in such a manner 

 as to force the fish passing on this side of the river to go in this 

 direction. The salmon, wishing to cross the very rapid stream 

 where the wheel is placed, is raised out of the water by the iron 

 wire on the blades. In the rotary movement the salmon is carried 

 to the centre of the wheel, whence an inclined plane conducts it 

 into vast open reservoirs placed in the stream, where it can be 

 kept alive for some time. A system of pulleys provides for the 

 raising of these reservoirs, the water flows out, and the salmon is 

 carried in boat-loads just as it is required for preparation. 



— A new instrument, called the " schiseophone," lately in- 

 vented by Captain de Place (a French officer), is described in 

 Engineering The object of the instrument is to reveal the pres- 

 ence and the place of any blow-holes, flaws, cracks, or other 

 defects which may exist in the interior of a piece of metal. When 

 these defects are very great, the blow of a hammer on the piece of 

 metal soon betrays their presence, but for small blow-holes, 

 although these may al^be very dangerous, there is not enough 

 difference in the sound given by the hammer striking the piece of 

 metal for it to be detected by the ear. The schiseophone, how- 

 ever, will enable that difference to be heard. The apparatus 

 consists of a pin which runs through a microphone of a special 

 construction, which, as usual, is put in connection with the current 

 of an electric battery. Without giving more details of the com- 

 plicated mechanism of the instrument, one can understand that, 

 when the pin strikes on a good part of the metal tried, a sound is 

 produced, the vibrations of which affect the electric current in a 

 certain way and then a certain sound can be heard in the tele- 

 phone attached to the instrument. When the pin strikes on a 

 part of the metal where there is a defect, the sound produced is 

 different; the microphone, the current, and the telephone are then 

 affected differently, and the defect existing in the metal is revealed 

 by the difference in the sound heard at the telephone. The ear 

 must, of course, be used to the different sounds to be able to dis- 

 tinguish them ; but the necessary skill is not very difficult to 

 acquire. Trials with this instrument have been carried out at 

 Ermont, at the works of the Northern Railway Company of 

 France, in the presence of many engineers, to find defects in the 

 rails. The telephone of the apparatus was placed at a long dis- 

 tance from the rails, from which it was also separated by a wall. 

 The points where the instrument intimated a defect in the metal 

 were carefully noted ; the rails were then broken at those places 

 and the defects were actually found. 



— The great Australian expedition has succeeded in traversing, 

 from north to south, the first or most southerly of the three great 

 blanks it was commissioned to explore. This is the wide interior 

 space lying between the track of Forrest in 1874 and that of Giles 

 in 1875. The party crossed the boundary between South and 

 West Australia, at a point to the east of Fort Mtiller, in latitude 

 26° 10' south and longitude 138° east, and struck south across the 

 desert from Mount Squires, making for Queen Victoria Spring, on 

 Giles's track of 1875. Arriving at that expected abundant water- 

 supply, they found it nearly dry, and all hopes of a thorough ex- 

 ploration of the region were destroyed. Under these circum- 

 stances, and sorely straitened for water, a direct route was taken 

 for the nearest cattle stations, near the southern seaboard of West 

 Australia and Esperance Bay, from which latter port Mr. David 

 Lindsay, the leader, despatched reports of the expedition to Ade- 

 laide in October last. The country traversed appeared to have 

 had no rain for two years. Owing to admirable management on 

 the trying march of 560 miles through an almost waterless coun- 

 try, the health of the party had not suffered, and only two of the 

 camels had died. Notwithstanding the utter aridity of the re- 

 gion, Mr. Lindsay remarks that it cannot be called a desert, for 

 the country is more or less clothed with bushes and trees, and for 

 many miles there is a gum-tree forest which extends into South 

 Australia, the trees reaching often three feet in diameter and 



forty to fifty feet in height. He adds that the clean white trunks 

 and dark-green tops of the trees from a short distance present a 

 charming aspect, but that a nearer examination reveals the usual 

 signs of aridity, the ground being covered with nothing but the 

 desert- loving spinifex and useless shrubs. Mr. E. A. Wells, the 

 surveyor of the expedition, reports that the whole of the country 

 travelled over from Mount Squires was inhabited by natives who 

 got their water-supply partly by draining the roofs of certain 

 mallee trees, some of which, distinguishable only by the keen ob- 

 servation of a native, yield quantities of pure water. It was Mr. 

 Lindsay's intention to remain near the south coast for some weeks 

 to restore the strength of the sorely-tried camels, and then to 

 proceed again towards the interior, taking a more westerly route, 

 so as to cross Giles' route at UUaring, and Forrest's track at Mount 

 Ida, and thence on to Hope's Station via the new gold fields. 

 From the last-mentioned place he had hopes of making an excur- 

 sion south-east as far as latitude 38°, and thus completing suffi- 

 ciently the examination of the first great ai'ea it is the object of 

 the expedition to explore, before proceeding to the second, further 

 north. 



— A magnificent diamond, a perfect octahedron, weighing 205 

 karats, has been purchased from a river digger by a Kimberley 

 buyer, says the South African Mining Journal. It is the second 

 largest stone ever found in the Vaal diggings, the largest being 

 the celebrated Spalding diamond of 380 karats, but which was 

 yellow and of bad shape. The price paid for the stone recently 

 found is said to have been £2,000; since his return from the river 

 the buyer has been offered £8, 000 for it, which offer has been refused . 



— The Engineering and Mining Journal of Jan. 30 gives an 

 abstract of a paper by N. Lebedieff on a direct process for pro- 

 ducing iron and other metals from then- ores. According to this 

 method the metallic oxides are brought in contact with a strong 

 base (potash, soda, lime, or dolomite) by either melting the two 

 in a finely divided state or by roasting such mixture in furnaces 

 provided with a powerful air blast, stirring the mass frequently. 

 To hasten the process common salt or nitre may be added to the 

 roasted mixture. Some combinations of metallic oxides with 

 alkalies may be produced by the wet process; for example, alkaline 

 aluminafes. Abstracting the pure metals may then proceed in 

 cupolas, open hearths, or in crucibles in reverberatory furnaces. 

 To the mixtures prepared as above are added charcoal, coke, etc., 

 as well as a proper amount of silicious materials to produce slag 

 upon the reduction of the metals. In order that furnace walls 

 be not attacked the inner lining is best made of neutral material. 

 In the reduction of iron and other metals easily separated by coal, 

 etc., gas, under proper pressure, containing a sufficient amount 

 of CO2, H, or C4H5 may be used instead of coal, etc. Smelting 

 is then carried on in open hearth or reverberatory furnaces. The 

 reducing gases are brought into the molten mass by pipes dischai'g- 

 ing at a proper height, or by tuyeres issuing from chambers in the 

 furnace walls, and connected with pressure generators or gaso- 

 meters. After properly heating the furnace the carefully mixed 

 oxides and bases, or the oxides previously treated with bases, are 

 introduced and heated until thoroughly melted, when the reducing 

 gases are allowed to penetrate the mass. In proportion to the 

 relative reduction of the metal and separation of the bases a fur- 

 ther thin layer of oxides is added. These latter combine readily 

 with the free base and melt, and the gas then again reduces the 

 metal, the base is again separated and thus the process continues. 

 In case the oxides combine readily with the bases by simple smelt- 

 ing the operations can all be carried on in one furnace. Metals 

 melting easily are tapped from time to time as they are produced. 

 Metals which are refractory, such as iron, chromium, etc., can be 

 dosed with materials which lower their melting point (high carbon 

 pig in the case of iron), or else they are treated, after a sufficient 

 quantity has been produced and removed from the furnace, with 

 water or acids after cooling, thereby dissolving the alkaline salts, 

 the insoluble metal remaining undisturbed in the shape of small 



— Dr. Charles S. Edwards, fellow in Clark University, Worces- 

 ter, Mass., has been appointed assistant professor of biology in the 

 University of Texas. 



