The age-herald., 1897-09-26
.nNOTES ON SCIENCE AND INDUSTRIAL.

in it's bore is hollow capable of hold ing a considerable quantity of slow burning powder; a plug screws into this hollow holding the powder s scuTeiy within. Around the edges of this plug are a series of gTooVss leading into the powder chamber, and bored at an angie opposite the direction in which the pro- jectile is expected to twist, and thus bores its way through the air, doing this on the same priHeipl9 that makes the pin wheel revofve when 1t is light ed. A charge of quiek-burning powder is dropped into ths smlaloth-bore cannon, and the projectile is pushed in upon it; .he fuse Is aitachsd and the cannon fred-the quick-burning powder expedt- ing the projectlle and lighting the slew burning powder through the grows. This begins to act at once, acceleratlng the spesd and initiating the twist even before leaving tine cannon. The speed is said 10 actually increase while fne projectile is in the air. and until the powder is burned out the rotary molioil continues to accelerate the ball.
 One of tlhe recent inventions mentioned amonig those brought forward in Ger many is one credited to Paul W WohnS- b--ger OF Grunoa, and the means py which this quality is insured is claimed to be easily practicable Within the heel of tine shoe, which is adequately hollow ed cut for the purpose. there is a necep- . tacle for glowing substance similar to that which is usld in the weM-known Japanese hand warmers. Between the So'es, imbeidded in asbestos covers. there is placed a rubber bag which is filhsd wit water, the latter being heated above the heel, and as it circulates while the wearer of tfIs shoe is walking 1t Keeps the entire neither surface of the foot warm; small safety valve is provided, so that the bag cannot burst. The warmth given by this kind of sole is said to nsver rise above 70 degrees F., and will last for about eight hours. The shoes are slightly heavier than the or- dinary sont, the sole being but little thicker than that of the so-called wet weather boot.
 One of the most common objections to the use of rubber in it's various applica- tions is its quality of crumbling or breaking after it has been in use a while, this being characteristic of all varieties of the article. A number of ingenious methods for the prevention of this in convenience have from time to time been proposed, but, according to the San Fran cisco Scientific Press, the most reliable Of these seems to be the least compd- cated, namely, the occasional immersion of lhei rubber articles in a per cent. Sc- lution of earbolic acid. Though a. very simple and inexpensive process, rubbsr tubing trea ted in such a manner is found to remain in excellent condition, even after many years of use; in fact, rubber bands given an occaS lonal carbolic acad bath ara practically indestructible in- stead of being really worthless without such treatment.
 The manufacture of steel barrels is a nsw industry aauely established near London, England. The difficulty of giv- ing the steel sheet the ordinary barrel shape is overcome by easing the curved .a.,1xv in the middle, thus stretching the metal at glhe centre and forming the barrrel body complete, with the exception of sifearlng the ends straight in a special machine and welding the seam. The we ding is done by electrically melting the pieces of steel over the opening and hammeTng them down; t.se heads are cut in a circular shearing machine, corru gated and dfshed in a 4G0-tln hydraulic press, and secured in place by ring of metal which is welded both to the end of the barrel and the head; the bung bosses are also welded on-no skilled la Dor being required fer the process, and but moderate power is needed to supply the current.
 The superiority of diffused light over that which is direct is now generally insisted upon by scientific experts the fact being urged that, while the latter wSaiieS the eyes and preliiSposeS to shortsightednees the former is, like sum- shine, soft and soothing The principle involved in lighting 8 room by this method is certainly sufficiently simple and practicable for it's general adoption, upon the ceilings and walls the required luminous rays. which thus falls softly on the desk or work table. All that is necessary to secure this result is to place "a reflector not above the source of light, but below it, by which arrange ment all the rays are reflected toward the ceiling. In some of the public assem- bly places and institutions of France unique methods are resented to in carry ing out this plan-aS at the school of St. Cyr, where conical reflector. paint ed entirely white, is placed upon the arc lights-while at the lyceum in Aix par abolic reflector is used which is bronZed on the lower and silvered on the upper t,sa rt. a tyraat liobt jS tb,1c abfoipaa fo