36 



NATURE 



[November 8, 1900' 



A telephone wire which had broken fell upon the overhead wire 

 of the new electric tramway line and made connection with the 

 earth. A lady, who got caught by the loose wire, and three men 

 who went to her assistance, were injured by the current. Two 

 of the persons were so seriously injured that they had to be 

 taken to a hospital, and one is not expected to recover. From the 

 report it is not quite clear how the woman got entangled with 

 the telephone wire, and if the wire coiled round her in falling 

 she might, of course, have been seriously injured, even if no 

 current from the overhead wires of the tramway line had been 

 passing through it. There is danger when a wire breaks, 

 whether the wire comes in contact with one conveying a strong 

 electric current or not. The accident might, however, have 

 been prevented had nets been placed, as is sometimes cautiously 

 employed, over the tramway overhead wires at places where 

 telephone or telegraph wires cross them. 



At the Imperial Institute, on Monday, Mr. James Stirling 

 discoursed upon "Golden Victoria, its Scenery, Geological 

 Features, and Mines," and gave a glowing account of its re- 

 sources. Victoria, although the smallest State in the Australian 

 Continent, is the most varied with regard to its surface features, 

 natural resources, climate, &c. It has produced, during the 

 last half -century, more gold than any other country in the 

 world, California excepted, viz., 256 millions out of the total 

 413 millions produced by Australasia. Bendigo, the deepest 

 mine, is now 3434 feet in depth. Boring operations have proved 

 that deep auriferous leads of about 400 miles in extent exist in 

 various parts of the Colony. The coalfields cover, in Gipps- 

 land alone, 3000 square miles of territory, and the seams are up 

 to 5 feet in thickness. In several valleys, such as the Latrobe, 

 immense deposits of brown coal 276 feet thick have been found. 



The Times states that the practicability of utilising Mr. 

 Marconi's system of wireless telegraphy in connection with the 

 mail packets running between Dover and Ostend has just been 

 tested, with satisfactory results. The vessel selected for the 

 demonstrations was the Belgian mail packet, Princess Clementine, 

 commanded by Captain Romyn. The installation was fitted up 

 in one of the private deck cabins on the starboard side. The 

 receiving and sending wires were connected to the foremast, the 

 height of which had been considerably increased. The land 

 installation was set up at La Panne, on the flat coast between 

 Ostend and Dunkirk, the mast being about 130 ft. in height. 

 The distance between La Panne and Dover is 61 miles. The 

 Princess Clementine left Ostend soon after 1 1 o'clock on Saturday 

 night and arrived at Dover at 2.40 on Sunday morning. Captain 

 Romyn described the results so far beyond anything which the 

 Belgian authorities had anticipated. A message was trans- 

 mitted from Ostend to La Panne when the Princess Clementine 

 left the Belgian port, and telegrams continued to be exchanged 

 between the vessel and the shore at frequent intervals during 

 the voyage to Dover. The messages were transmitted at the 

 rate of about twenty words a minute. Messages were exchanged 

 right up to the time the vessel reached Dover. 



The Indian Meteorological Memoirs (vol. xi. Part II.) con- 

 tain a discussion of the observations recorded during the solar 

 eclipse of January 22, 1898, at 154 meteorological stations in 

 India, by Mr. J. Eliot, F.R. S. The weather was very fine 

 over India generally, but at some of the more southerly 

 stations the sky was overcast. The cooling effect of the eclipse 

 was marked over the whole area ; the maximum decrease of 

 temperature ranged between 8° in the belt of totality to 4° in the 

 extreme north and south, the maximum decrease occurring 

 about twenty minutes later than the maximum obscuration of the 

 sun. The movement of the air was very light generally, and 

 was practically suspended during the greater part of the eclipse, 

 but a noteworthy feature was the occurrence of a short, sudden 

 NO. 1619, VOL. 63] 



gust about twenty minutes after the commencement of the- 

 eclipse at the majority of stations in and i>ear the belt of totality. 

 There was a remarkable increase in the amount of aqueous 

 vapour, which commenced about the middk of the eclipse and' 

 was followed by an equally rapid decrease. This last feature 

 was the most remarkable and unexpected phenomenon of this 

 eclipse ; it was exhibited at all stations, and was most pro- 

 nounced at stations in the interior, on and near the line of 

 totality. The diurnal variation of pressure was also consider- 

 ably modified, the decrease of the amplitude averaging about 

 ■03s inch. 



At the request of the Austrian Ministry of Agriculture,, 

 various experiments have been made by Drsi Pernter and' 

 Trabert with the view of testing the use of Mr. Stiger's appa- 

 ratus for dispersing hail-clouds by gun-firing. The apparatus- 

 consists of a mortar with a long funnel fixed to the orifice ; upon- 

 firing a sufficient charge of powder, rings or whirls are formed' 

 in the air and can be followed either by their hissing sound or 

 by the particles of smoke carried up with them. The force and' 

 durability of the whirls vary with the charge, and' with the size 

 of the funnel, but it does not appear from the experiments that 

 a greater altitude than about 400 metres was reached, which is- 

 much less than had been previously stated. It does not seem 

 probable, therefore, that unless the hail-clouds are very low that 

 any practical result is likely to be attained. The most that can^ 

 be said in favour of the process is that while in some cases the- 

 formation of hail may have been prevented by the disturbance of 

 equilibrium, hail frequently falls, in spite of frequent firing. The 

 particulars of the experiments will be found in a recent number 

 of the Meteorologische Zeitschrift. 



Dr. Goldschmidt, of Essen, has recently described a new 

 welding process invented by himself (says Fielden^s Magazine- 

 for October). The heat required is obtained by means of a' 

 compound called ** Thermit." Metallic oxides, with aluminium, 

 are its constituents, and it has the property of allowing a fusible 

 mass at a high temperature to be quickly and simply produced. 

 Its use in welding pipes and rails is its most interesting appli- 

 cation, as, with its aid, rails can be welded immediately and 

 economically and at anyplace, a melting-pot or^ly being required. 

 The details of the process are stated as follows : — " The melting- 

 pot is filled with tar-oil, an inflammable mixture is added, and 

 a match is used to ignite it. Spoonfuls of * Thermit ' are then 

 added, which immediately ignites and produces temperatures as 

 high as 3000° C. The highly incandescent contents of the pot 

 consist of iron, called alumino-thermo-iron, on the top of whichi 

 floats melted carborundum. An aluminium oxide is then 

 poured on to the part of the rail to be welded, and the work is 

 done so quickly that the melting-pot is cold and can be taken 

 into the hand after being emptied." 



Some interesting observations on dielectric hysteresis have 

 been lately published by M. F. Beaulard in the Journal de- 

 Physique. With condensers of paraffin and mica, little dis- 

 sipation of energy by hysteresis was found, but with dielectrine, 

 curves of hysteresis of the well-known forms were obtained. It 

 was found, however, that the area of the curves and therefore 

 the absorption of energy, varied with the period of time in which 

 the cycle was performed, being less for slow than for rapid cycles. 

 All this, the author considers, is explicable on M. Bouty's 

 hypothesis, according to which the electric residue is due to a 

 temporary retardation of the Active polarisation on the polarising 

 field. It is to be remarked that M. Pellat has rendered Bouty's 

 explanation independent of the notion of fictive polarisation by 

 proving the existence of a real polarisation varying with the time, 

 thus explaining the phenomena observed in the present experi- 

 ments, without assuming the existence of hysteresic properties in. 

 dielectrics analogous to those in magnetised bodies. 



