Arizona republican., 1912-02-28
SCIENTIFIC MISCELLANY

The art of cinematography is rap i idly entering into our lives. and in | addition to giving popular records of | interesting events, moving pictures 1 in the future are to play an import
 ant part in education. medical and 1 other science. the arts, and even in commerce A recent development has
 been the production of X-ray moving i pictures of the internal organs and
 parts of the body. For rapid motions | like those of flying insects, a new apparatus takes 2,000 successive views
 a second on 125 feet of film, and.
 as the usual stopping of the film for each exposures is impossible at such speed, the exposures are given by | electric sparks, each lasting not more than 1,140,O00th of d second The picture may be shown on the screen at one one -hundredth as great speed, or the ordinary moving picture rate of 1J or 20 successive views per sec Ond. thus giving a better perception
 of motions that originally are diffi-
 cult for the eye to follow. A new
 Edison ..romise is that of q home
 llinetOscope. that will make moving pictures available for everybody for varied purposes. It is announced that
 what now requires 1000 feet of film
 will be compressed upoin so feet. and
 the apparatus will compare with a
 sewing machine in cost An illus
 tratiOn of commercial possibilities is
 the salesman's idea of moving pie
 lures to show a machine at work
 The high price of platinum has held the international committee of weights and measures to favor the use of tantalum, which is hard and unalter- able, and from which standard weights can be made at third of the cost of those of iridio-platinum.
 The danger of swimming pools re- cognized within a few years seem to | require only simple treatment. Whip | pie and Bunker in late paper to | the American Society of Municipal | Improvements, state that at least one | typhoid fever epidemic spread by q | swimming pool is on record. and it | is believed that nose and throat af- | fectations are transmitted by the wa ter. Repeated analyses at American | colleges have shown that contamina- tion with organic matter increases from day to day while a pool is in use. The high temperature at which the water is kept favors bacterial | growth. and the bacteria-to which each person adds dispite any pre- cautions-soon multiply to the limit fixed by the food supply. The ex- .l<,. trouble can be easily regulated by dsinfection. Ordinary bleaching pow der. or calcium hypo-chlorite, which has recently gained such favor in drinking water. proves equally effective in the swimming pools. and is insured by adding every two or three days enough disinfec- tant to supply 0.5 to 1 part of avail able chlorine per million parts of wa ter.
 In the volcano theory of R. A. Daly i is is assumed that the outer portion of the earth is composed of success sive shells having a density increas- ing with the depth. The broken and sedimentary shell over lleS d tcllluuouS SciIu oIitii, l and this in turn rests upon an erup tive basaltic shell or substratum. Al!
 gneous action since long before Cam brian times is regarded as the result of injection of the substratum baSalt into the overlying shell. Two main classes of eruptions are recognized. aside from tissue exemptions. the prin- ripal having vents for injections, di- rect from the substratum, and the receiving injections in directly through laccoliths or intru- sive sheets deposited as Offshoots of the basalt substratum and at some height above it. Kilauea is classed with the subordinate type. Principal volcanoes are more active. of longer duration, more productive of lava flows, and are more clearly related to features of the crust. Explosions are thought to receive their energy from sources quite deep-not primar- fly from local steam.
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