Pine Bluff daily graphic., 1901-10-03
LIGHTNING FLASHES.
HOW THEY ARE EVOLVED AND THE
 ENERGY THEY POSSESS.

AMna Dftants of COmpactiy Built Cities Have Little Cause to Fear
 These Mysterious and Destructive K Balls From tke Clouds.
 Without doubt lightning was the first
 electrica. phenomenon tLat was obsery-
 cd by human beings. To this day it
 remains the least known and least up-
 Aerstood of natural electrical manifes- tduonS except. perhaps. the aurora There Is vast deal of popular mis- l conception concerning the danger of
 Lightning and the nature of it. The
 nghtning flash is a discharge from a Cloud at a high potential with refer- N ence to the earth. When the atlnos-
 pnefe Is charged with water vapor and some eddy or current in it's colder up- N per strata is deheeted downward, caus- B. Ing condensation, exceedingly minute Nsurops or water arc formed each bear Ing an electrical charge The consoli- HQatlon of these into larger drops results 2 1n very great increment of the poten-
 llal of the charge since tie capacity of
 Ine drop varies with its diameter and sa rne volume of the drop with the cube 1of the diameter
 1sEg The consequence of this is that if taKes, tor example, eight drops consoli- I 0hlea to make one of twice the dame- \ Ter ef the constituent drops, and the &nQrge on the surface of the consoI- Nated drop will be four times as great &s that upon the surfaces of it's ele nents. In this way, as the small wa | 4er particles unite to form drops which Hail as raIn the potential Of the charge Ehey carry increases until it attains ! hehormous values, and the lightning aAash leaps to the earth, which may be regarded simply as q body of very -great eleetrostatic capacity The dis
 charge, which is called lightning, is \ apt to De more or less destructive. al- Vthoush the energy of an individual snash is perhaps not very great. Often
 the conditions are such that the dis
 charge takes on an eseiliating eharae- alter, producing violent surginss of eur ldrent. No very accurate measurements
 nave been made Gpon the current in- involved. but it is taken to be of the or < Ter of 1000 to 5,ee0 amperes. The llpslectro motive force necessary to cause twt flash mile long is probably several 0nillion volts. and of course the power l If the flash measured in watts is very
 .reat, but it's duration is correspond .ngly short.
 Protection Of property and life from lightning flashes has been q subject hat has eEtrained the attention of
 aatural philosophers since Franklin |
 ent up his historic kite The net re G ult of more than q century of attempt z Q secure protection has been the light ing rod in it's more or less inefficient forms and the discovery that buildings MI modern construction. having metal
 lc roofs and often metallic frames as | well, 2"o practically immune from at
 ack by lightning
 The total lumber of deaths due to |
 ghtninS in any giYen summer is con-
 aratlYely very small-in the ratio of |
 bout ci.e to each 100000 population ill
 he United States In cities the de truetiSe=infiueace of lightning is ex- . eedinsly small, although occasional
 res are caused by it. especially where
 as pipes abound
 Protection of electric circuits from ' ghtnili;, has been an interesting sub B fct for research fer number of years, nd several highly efficient devices
 ave been constructed for this purpose.
 oday lightning is little feared by the alton superintendent and should be cry little feared by any one. The
 me hoaored rule that it is wisest to
 feep in the open and not seek the shel-
 Nr of trees is one which common pru- e,nce dictates. Recourse to the featl-
 Nbed of GUT ancestors, however, is no
 nger necessary except to quiet the
 .rves of timorous persons. while the Olcient superstitions regarding han ing steel instruments and sitting in
 afts may he utterly disregarded \
 odern building in q city is as nearly
 ,solutely lightning proof and those in j -tare as nearly absolutely protected
 om lightning as is possible.-Electric-
 Review [;