Fort Wrangel news., 1898-07-06
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 The sound of n bell which can be heard 45,0OO feet through the water can hr heard through the air only 456 feet.
 From the 140 pounds of gas tar ex- traetrd in cooking a ton of coal over 20G1 distinct shades of aniline dye are maGn.
 \ process has recently been perfect cd ,y which thin sheets of absolutely Transparent cellulold are sllyered sim llarly to the process formerly used on glass.
 A determination of Prof. Barnard with the Lick telescope places the di- amctrr of Neptune at 32,9OO miles from 1000 to 4,0OO miles less than Is stated in text books.
 Ii iS said experiments made recently hy scientific men in France have deyel- oped curious and altogether uneX- pectpd fact, namely, that certain per soHS possess Il magnetic polarity-that k. tEey are found to act after the man. ner of magnets.
 Th.rc has been a competitive test of fire engines in Philadelphia. ln which il Was proved that the type with piston had superior advantages over the rot. ary. The piston engine consumes less coal. does better work and keeps 1t up longer than the rotary
 A gold-dredging boat, fitted with elaborate machinery, has recently been put to work on the Yuba River, in Cali fornia. The chain of buckets connect ed with the bont-the latter being 0G feet long and 23 broad-brings up gray el from the river bottom, and Is capable t. acting at any depth up to 60 feet. The gravel. sand and mud are passed through screens and over tables being thoroughly washed with water supplied hy a centrifugal pump, and gold In ..raius 50 fine as to be invisible to the gakcd eye Is thus recovered. The cost oi dredging k said to be only three crniS per cubic yard.
 Tests have recently been made at the I.i4hthouse Depot on Staten Island of an electric light beacon which 1t Is ex- pected. will be set up at some import ant point on the Atlantic coast. The illulnination is furnished by an arc light of 9,GOO-candle power, but this Is refiacted by Il series of eccentric priS- matir segments. so that the light Is projected in q parallel beam nine feet in diameter, which Is estimated to be of no less than UOO,OOO-candle power. Such light would be visible in q straight line at Il distance of 169 miles. bat owing to the curvature of the earth the actual distance at which it could be seen would depend on its elevation above the sea.
 Charles l.. Tripler of New York. the Scientific American says, has accom- plish,d the economical liQuefaction of air in large quantities. He recently >ent two and d half gallons of liquid air to Prof. Barker, of the University If Pennsylvania. The latter found that | piccc of tin thrust into the intensely old iuuid-311.S degrees below Zero, aarcnheit-became as brittle as glass. but that copper and platinum were not thus affected. This suggests the proper metals from which vessels intended to roa'ain liquid air should be made. The nitrogen of the air liquetles at tenn peHature several degrees below the puiat at which oxygen becomes liquid: consequently when liquid air Is allowed to eyaporate in an open dish the nitro gen ynporizes first. and what remains i> mostly liquid oxygen, which possess seS a characteristic blue color In Mir Triplpr's apparatus the mir, after pass ing through three coils. each colder than the preceding, finally flows from the end of the last coil In q liquid stream.