76 



SCIENTIFIC NEWS. 



[June 1st, 1887. 



GENERAL NOTES. 



Public Telephones. — An automatic toll-taking device for 

 public telephones is being experimented with. The drop- 

 ping of a coin of sufficient size and weight is used to com- 

 plete the electric circuit. 



Deep-Sea Photography. — Experiments made in France in 

 " deep sea " photography have been successful. With a 

 camera and the electric incandescent light it is said to be 

 possible to photograph sunken ships, and make simpler the 

 diver's perilous work. 



Rice Cement. — A cement very much used at the present 

 day in China and Japan is made from rice. It is only 

 necessary to mix rice flour intimately with water and gently 

 simmer the mixture over a clear fire, when it readily forms 

 a delicate and durable cement. 



Sea Water made Drinkable. — A new discovery is that 

 sea water may be made drinkable by the use of citrate 

 of silver. B3' this means chloride of silver is precipitated, 

 and a harmless mineral water is produced. An ounce of 

 citrate makes half a pint of water drinkable. 



Electric Indicator for Looms. — A manufacturer of 

 Roubaix has invented a useful application of electricity to 

 looms. He adopts an indicator which strikes when a thread 

 breaks, and thus saves the weaver from the close attention 

 to the quickly-moving threads which is so injurious to the 

 sight. 



Rheumatism or Trichinae. — An assistant of Professor 

 Virchow, Dr. Grawitz, finds that about one-third of the 

 cases pronounced in life muscular rheumatism, are shown 

 by post-mortem examination to be due to trichinae, or pork 

 worms. In instances observed, it is said the parasites must 

 have been present in the muscles for many years. 



Cast Steel Tools. — A Swedish engineer, Mr. Gustafson 

 Odelstjerna, has devised means of making hatchets, ham- 

 mers, shovels, and other tools with steel of good quality, 

 and at a low cost. The tools, are cast direct from steel, 

 mixed with from one to four per cent, of chromium, and 

 are said to be much stronger and better than when made 

 of iron. 



Hot Water from the Earth. — The earth's internal heat 

 is now being used in a practical way at Pesth, where the 

 deepest artesian well in the world is being sunk to supply 

 hot water for public baths and other purposes. A depth of 

 3,120 feet has already been reached, and the well supplies 

 daily 176,000 gallons of water, heated to 150 degrees 

 Fahrenheit. 



Electric Whistle. — An electric whistle is easily made 

 by fitting a small brass tube with suitable apertures so that it 

 opens against the spring of a make-and-break of the usual 

 electric hammer type. Such whistles are cheaper to make 

 than electric bells, and may be made to give very melodious 

 sounds. They have recently been introduced in France, 

 and their use seems to be meeting with favour. 



Nickel and its Alloys. — According to Invention, Herr 

 Fletmann, of Iserlohn, has shown that pure nickel and its 

 alloys with copper, cobalt, and iron can have other metals 

 added without losing the property of being welded, and 

 therefore can still be used for making plate. The metals 

 which can be added in this way are zinc, tin, lead, 

 cadmium, iron, and manganese, up to as much as ten per cent. 



The Congo Railway. — The Congo Company, which has 

 the concession for constructing a railway, is sending out an 

 expedition to select the best route, and to explore the coun- 

 try adjoining the Upper Congo, with a view to its commer- 

 cial development. It is expected that the railway, which 

 will join the Upper and Lower Congo, will be from 250 to 

 300 miles long. The expedition will be in charge of 

 Captain Thyo, a Belgian Officer. 



Curious Pebbles. — In the quaternary gravels of the 

 Loire Valley, France, there are numerous specimens ot 

 stones, about an inch and a-half in diameter, which are re- 

 markable for being hollow, and enclosing liquid water, and 

 sometimes a loose stony nucleus. It is supposed that the 

 water must have penetrated the pebbles through their 

 minute pores, for not a sign of a crack can be seen, even by 

 the aid of a strong glass. 



Crystals of Spodumene. — The crystals of spodumene 

 brought to view by the excavations in the Etta tin-mine in 

 Pennington County,'Dakota, are believed to be without a rival 

 in respect to size. According to the report made on this 

 subject by Professor Blake, it appears that one of these 

 crystals is thirty-six feet in length in a straight line, and 

 from one to three feet in thickness. The cleavage is smooth 

 and straight, but the lateral and terminal planes are de- 

 scribed as being obscure. 



The Speed of Toboggans. — Mr. Bowditch, President ot 

 the Albany Toboggan Club, has had the speed of the tobog- 

 gan determined. At the point of maximum rapidity, i.e., 

 just where the toboggan leaves the chute for level ground, 

 the speed is ninety-three miles an hour. These timings 

 have been made repeatedly by a competent engineer, and 

 for that chute are very probably correct. The speed of the 

 toboggan exceeds, therefore, all vehicles — even the fleet ice- . 

 boat never reaching such a terrific velocity. 



Halibut in Fresh Water. — A halibut weighing thirty-four 

 pounds and measuring forty-one inches in length was 

 captured recently in the lower Potomac, near Colonial Beach. 

 This is the first authentic case of a halibut in fresh water. 

 Hitherto it was supposed that the vicinity of Long Island was 

 the extreme southern limit of the habitat of this fish. The 

 specimen caught in the Potomac has been preserved in 

 alcohol by the Smithsonian Institution, and a cast has been 

 made and placed on exhibition in the National Museum. 



Morphinomania in Monkeys. — It appears from a memoir 

 sent by Dr. Jammes to the Academie des Sciences that, unlike 

 other animals, monkeys readily acquire the habit of taking 

 morphia. When monkeys live with opium-smokers, and 

 become accustomed to a medicated atmosphere, they acquire 

 a taste for the poison. One monkey, for instance, would 

 wait until its master had laid aside his pipe, and would then 

 take it up and smoke what remained. If not allowed to do 

 so for several days, it would fall into a state of depression 

 and stupor, which disappeared as soon as the stimulant was 

 supplied. 



Rain Clouds. — A communication to the London Meteoro- 

 logical Society, by Captain Toynbee, states, as his con- 

 clusion, that clouds of not less than two thousand feet in 

 thickness are seldom accompanied by rain, or, if they are, 

 it is very gentle, consisting of minute drops ; with a thick- 

 ness of between two thousand and four thousand feet, the 

 size of the drops is moderate ; with increasing thickness of 

 the clouds comes an increasing size of the drops, and at the 

 same time the temperature becomes lower. When the 

 thickness amounts to more than six thousand feet, hail is 

 produced. 



To Preserve Zinc Plates. — Plates of zinc, such as are 

 used in lithographic and zincographic establishments, may 

 be spoiled by a single drop of water being left on them by 

 inadvertence. Mutton fat is an excellent means of pre- 

 venting oxidation and the influence of humidity. Before 

 using it, the plate must be rubbed perfectly dry with a smooth 

 and clean linen rag ; then the fat is lightly rubbed over the 

 stirface. When the plate is to be used again, the grease 

 may be easily washed off with spirits of turpentine. This 

 process is used with the best results in German and Aus- 

 trian lithographic establishments. 



