POPULAR MISCELLANY. 



425 



bow. The carbon, which is made from paper 

 or wood, is not placed in a vacuum, but in 

 a rarefied atmosphere of gasoline, the idea 

 involved being that, as the strip wears away 

 under the action of the current, it will be 

 continually renewed by the free carbon of 

 the dissociated hydrocarbon vapor. This 

 deposited carbon forms a hard, compact 

 layer which seems to greatly increase the 

 durability of the strip, and also the amount 

 of light which it will yield under a given 

 current. None, it is stated, have broken, 

 even when forced much beyond the incan- 

 descence they are intended to bear, and, 

 owing to the compensating action of the 

 gasoline, it is anticipated that the lamps 

 will be permanent. The platinum wires 

 supporting the carbon strip are not fused 

 into the glass of the bulb, as has been the 

 case in previous incandescent lamps, but are 

 surrounded by a slightly elastic cement, 

 which it is averred preserves a good joint. 

 The light given by the lamp is but slightly 

 yellow, is quite pleasing to the eye, and is 

 fairly steady. It has, however, a perceptible 

 vibration, different from the irregular flicker 

 of gas, but more painful, and which it seems 

 impossible to eliminate, as it is due to the 

 necessary variations of the engine-speed. 

 As to cost, the inventor, Mr. H. S. Maxim, 

 claims that he is able to produce ten lights 

 of twenty candles each per horse-power. 

 Professor Henry Morton, of the Stevens In- 

 stitute, in a paper read before the American 

 Academy of Science, at its recent meeting, 

 stated that, experimenting with one of these 

 lamps, he found that, when it was giving a 

 light of forty candles, the expenditure for 

 power was at the rate of 240 candles per 

 horse-power. A twelve-candle light was at 

 the rate of 136 candles, and, at 49 candles, 

 was at the rate of 426 candles for the same 

 power ; while, when the lamp was forced to 

 98 candles, the expenditure was at the rate of 

 607 candles per horse-power. He also bore 

 testimony to the value of the gasoline vapor 

 in building up the carbon strip. It is doubt- 

 ful, however, if the gasoline will prove in 

 practice as free from disadvantage as ex- 

 pected. It will probably deposit in the form 

 of a film on the glass, that may in time so 

 obscure the light that a new lamp will be 

 necessary. Such a deposit seems to have 

 already taken place in some of the lamps at 



present on exhibition. The regulating de- 

 vice is quite simple in construction and cer- 

 tain in action. Its general mode of opera- 

 tion is as follows : The field magnets of the 

 machine supplying the currents to the lamps 

 are excited by another machine. The cur- 

 rent furnished by this latter is varied in 

 accordance with the number of lamps in 

 circuit, by shifting its commutator brushes 

 to and from the position in which they take 

 off a maximum and minimum current. This 

 shifting of the brushes is done by means of 

 simple mechanism, actuated by an electro- 

 magnet placed in the lamp-circuit, and there- 

 fore subject to the same conditions as the 

 lights. Numerous trials have shown that 

 this regulator is entirely reliable, and the 

 adjustment of the current is so delicate that 

 no observable difference has been detected 

 in the light of a lamp whether one or sixty 

 were in circuit. 



The German Anthropological Society. 



The eleventh meeting of the German An- 

 thropological Society was held at Berlin, 

 August 5th to 12th. The greater propor- 

 tion of the papers read during the ses- 

 sions related to relics discovered in Germa- 

 ny and the neighboring countries, most of 

 which were newly found, or newly reported 

 upon. Among the subjects of these papers 

 were prehistoric earthworks and fortifica- 

 tions in Schleswig-Holstein ; a Frankish 

 burial-ground near Worms, in which burials 

 in rows and in several courses of bodies 

 were notable features, and where dogs and 

 horses were found buried with the men, to- 

 gether with vessels of clay and glass of ex- 

 traordinary size and beauty, and a unique 

 bronze cup adorned with Christian emblems ; 

 the Frankish castle of Schlosseck in the Ise- 

 nach Valley near Diirkheim, hitherto wholly 

 unknown ; a report by Professor Virchow 

 upon the results of statistical researches 

 into the color of the skin, hair, and eyes, 

 illustrated by maps and tables ; prehistoric 

 charts of Germany by Professor 0. Fraas ; 

 the German Runes, by Dr. Henning, of the 

 University of Berlin. Dr. A. Bastian, who 

 had returned from a journey of more than 

 two years, undertaken for the study of facts 

 relating to anthropology, spoke of the im- 

 mensity of the task of perfecting the sci- 

 ence, which he realized more completely than 



