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I Bizri B. fj ed 4 I f I o-o o RadIo Ra e tv tlc nc m i II P R Rescue S cue f l j tr Ll Jj 1 I J Ii I ITh I Th r rI i I Ij t 1 I 1 Ij k y 1 j 1 SlY fr f f at I h t ll 9 q u Sir S Ja 1 o. o n 1 t i r r y Y A r 1 d J I r d t Kyr r r Ip t r 4 r f I Ii r i p tf 1 s df a f f r g rag r I i 1 f 1 lJ 1 i 1 y 1 Pr I y t 0 ty s. s r t r r l 1 J JIL N t Y IL r I R 1 9 r s Icy f Lr iJ y r reC Ji I I eC 1 fW L' L y yI rf 11 r N 1 0 t r I y W is 11 r t States Bureau oj of Mines fI r Experts Now Successfully x Through Solid Rock Dock J tj Many Feet Deep in Research Aimed at Saving Lives Cities ini in o i i Entombed Miners I Ir 11 HAT v T could be mo more e horrible e than than l r W i being g buried burled alive Y I It It is is-a is a a fate ate of which a great many I I r people entertain a. a haunting g dread Often Often Of- Of ten it happens that a person takes the most e elaborate borate precautions to make it certain that before he is is put into int his coffin the vital spark shall have hav left his body Yet despite 0 everything that that can can be bedone behim done to pr present ent such occurrences occurrences hUndreds hun hUn- hundreds hundreds of men are literally entombed ed alive aliye in this count country during every every twelve twelve- month We read of these happenings at not infrequent nt intervals in the the newspapers newspapers S SO often indeed that we have al almost ost ceased to react emotionally to the horror of them The victims are miners mostly mostly most most- ly ly the themen men who dig coal for us out of the he depths of the earth An explosion occurs in a mine perhaps per per- 1 haps laps 1000 feet below the surface of the I ground Tunnel roofs roofs' collapse i dozens or maybe scores of work- work t r ers era To dig ig their way out is a phys physical cal impossibility Their only chance of escaPa escape escape es- es lies in from outside outside outside-if if cape caPa succor happily happily hap- hap pill it can arrive before they die of thirst hunger or lack of air to breathe I If they are to be rescued no not a mini min min- mm- mm i j ute ate te is t to be lo lost t j a and d the first thing necessary nee nee-I essary is IS to find out exactly where and andl haw l i ow the entombed men are situated Sometimes they are able to convey information information in- in l formation by signaling with hammer- hammer 1 r r blows upon the imprisoning rock and j thereby to indicate the direction in which t ji digging x operations for their release should be conducted I I i t d a I It It is a p primitive primitive a an anI and d unsatisfactory I I. I method Hence during the last half- half 1 dozen years the government bureau of r Ie mines Wo Amines i ines has been trying to invent and I develop some sort of listening apparatus i by which signals sent through gh rock underground even for long distances I could be rendered intelligible J 1 S E i r i. i I In every proper properly I. I y equipped d mine mme now- now 1 fi days j there is a telephone system that 1 extends to all parts of it But usually it it t. t is s not of much much service in hi case of an explosion v for the explosion itself is likely to wreck the means of communication communication 1 cation caHon just when the latter latter is most sorely sorely sore- sore 4 ly ly needed r During the world war a an in instrument strument called a was developed of exceeding x delicacy for listening to sound jy waves ves conveyed through the surface strata of the earth It was used c chief chiefly Y to determine the location of enemy guns Later the bureau of mines adopted the I apparatus for employment in mines to receive signals made by hammer blows As' As yet however work with it has not gong gone beyond the experimental stage 1 a But lo to 1 t An idea now arrives that is x t entirely e ly new and which may be destined to to r effect a revolution in methods o of communicating with miners shut up in subterranean walled rock-walled death It is to use wireless telephony for the t. t purpose to purpose to develop means whereby the help of pf radio signals can be be sent through the rocks or possibly I conversation transmitted N I. I u If m men n imprisoned under such conditions conditions conditions condi condi- could actually talk with their would be rescuers telling exactly how they find themselves situated etc it w would uld give much help besides lending encouragement both to the entombed unfortunates and the workers who are striving to reach and lib liberate rate them Here then is a big hope though as asyet asyet asyet yet experiments ments have hardly passed beyond beyond beyond be be- yond the initial stage They are being conducted in an experimental coal mine because it has been used for fora a number of years by the bureau burea of mines for purposes of scientific fic investigation gation gation-at gation at Bruceton near Pittsburg The mine has hitherto been rented from froma I. I a coal company but congress has now appropriated money to purchase it The things that have been done to to that mine are astonishing Time and time timo again it has been experimentally blown up with tremendous explosions It 1 vas eras as there that demonstration was first made of the fact that coal dust will explode a truth previously denied by nearly all coal miners and coal oper oper- As now known most explosions in coal mines are explosions of coal dust which if mixed with air and ignited ignited ignited ig ig- ig- ig is as destructive as so much gun gun- powder More will be said later on about the the theT scientific Investigations at the Bruceton mine As A's s for the radio experiments the first one was an attempt to receive wireless signals In the depths from outside With the re receiving re- re Instrument far underground the signals signals signals sig sig- sig- sig nals were sent from a radio station at East Pittsburg eighteen miles away They could be heard distinctly It was wa presently noticed however that about fifty feet from the receiving st station used In this test there was a six-Inch six borehole borehole borehole bore bore- hole from the surface lined with iron pipe and containing light wires which extended throughout the mine The presence of these wires evidently helped greatly in n carrying carrying car car- the radio signals which followed along them It is upon this this principle that the so so- called wired wireless Is based This was soon proved for when the re receiving receiving receiving re- re set was carried to to toa a a. point in the mine far removed from wires and car tracks the signals were barely audible But of or far greater practical importance were subsequent experiments in the sending of or wireless signals through rock rocky strata underground The he re receIvIng receiving receiving re- re instrument took tool them intelligibly through fi fatty ty feet of solid soUd rock It was not much perhaps but for tor a b beginning it was as highly satisfactory The fact that radio waves could be peg transmitted through rock was demonstrated Every Everything must have a beginning and this idea is absolutely new If It fifty feet at the first try why not feet teet later on when there has been time to develop suitable suitable suit sult- able apparatus and learn exactly how to use I it The discovery w was s made only the other day And Already news has come that the experimenters have in increased the distance of or wireless communication through rock to feet One thing ascertained is that the signals lose ose distinctness very rapidly in transmission through rock when short wave lengths are used Longer wave lengths are known to suffer sutter less absorption as the technical phrase Is it is thought that they may prove utilizable to better advantage The problem is so new as to offer a virgin field to Inquiry and there is no telling what will develop next In connection with it In the meantime the United States bureau of standards is making experiments In droppIng dropping dropping drop drop- ping antennae down deep oil oU wells wells' to strata thousands of feet beneath the surface of or the ground and sending wireless impulses through the rocks of the earths earth's crust Instead of or through the air all The results obtained have not yet been made maCe known But the bureau of mines is referring Its Us own test data to the bureau of r standards and the two scientific scientific n- n organizations are working together to solve the puzzle here discussed ed So 80 far as the latest result wo we have radio messages sent and receives receive through feet reet of solid sandstone shale and slate Ina in ina ina a coal mine Before long we are likely to hear that the distance of or transmission has been doubled But nobody knows what will happen It is quite exciting and be beyond beyond beyond be- be yond measure important inasmuch as de development development development de- de of or the Idea may mean the saving savIng sav sav- ing of or a great creat many human lives annual annual- ly It may avail importantly to mitigate the horrors of ol explosions and other disasters disasters disasters In mines Much o of the moat Important work worle done 1 pl t t 4 1 n t d f j r r w J f E s. s SA EI l lY ly y Y la 0 f ff f f r. r A a J o 1 4 t rS Ir f ur J s sf f j 1 r R ay s 's r d f GAy It yh J. J Nn T F t v f t 4 J i Ik o ar p ak rC 9 ry Y f ry f ky a e. e i y r sr y t r J 1 fr ri J J gj i y A l' l ll lr Cie tit r N o r x r f J a f. f i y k d e r G l o r s f f J A r i Y t 47 1 J r l w r f Y fi rY 4 s sn attending a a. mine explosion is is fire and of the dangers n Y One greatest toOne tunnels are often sealed up after a disaster AI A Amine to prevent event its spread I mine rescue crew is here shown with gas masks al and d oxygen tanks closing up a drift along which flames are spreading ty r t c T r y fH 1 1 Jr J V VI I. I I w try n r U I I k p A J. J r j jr Y t A Ai L u a va i S r h K Kv v. v yC t e R T S JI 1 t M FD I b 7 Tak v hJ r a L Lv t. t v y AI Y h i l yi A 4 j r a f j C rL C p r ta II K t t r r rr r b an k rJ I alt I Listening f for r th the faint which will disclose the wh whereabouts whereabouts where where- reab re- re ab of imprisoned miners The a war device e which has been turned into a humanitarian instrument in In peaceful pursuits tells the listener here shown with the diaphragms diaphragms diaphragms dia dia- of the instrument placed o on a crevice in the rocks with the transmitters in his ears where the men have been trapped in the experimental mine at Bruceton during the past few years Years' has had to do with the tho development nt of or safety methods and appliances Enforced adoption of ot these methods and appliances by mine owners all over the United States has resulted In cutting down the number of or incidental accidental deaths by third one-third in the last three years rears The method of or organizing rescue work with the requisite drill was developed at Bruceton and in the laboratory laboratory laboratory labora labora- tory connected with the mine were Invented oxygen helmets and other apparatus now in general use Notwithstanding all efforts to minimize I the loss of or life ure in mines nearly o men were killed In the metal mines mine of or the I United States during the year 1922 In the same twelvemonth about 1900 were killed in fn the coal mines of this country Coal mining is an occupation far more dangerous than metal mining because of or dust ex ex- ex There are of ot course cours other hazards such as falls of rock Most of the deaths of or men in metal mines are caused by rock f falls 31 Is Another great peril perU of or the coal miner Is what he calls lire fire 1 damp a LI highly ex exI exl ex- ex l ex- ex I plosive gas cas which a spark will serve to ignite Not until very recently was It ascertained that this fire damp is nothing nothing- In the world but marsh gas known gas known to the chemist as methane It Is a very light hydrocarbon generated by decomposition tion of or vegetable matter Thus in marsh marshy or pr boggy bogg places it sometimes appears be becoming becoming be- be coming luminescent In the form of hovering lights mysterious and suggesting the supernatural People call them will the o The same gas gaa in coal mines comes from remains of or plants that grew ages ago and aid which are the material of or orthe the coal The mine at Bruceton is somewhat over overa a quarter of a mile deep It Is the only mine In the world that is s owned by a aI I government and used for tor purposes of ot scientific exp experimentation Recently thero thera was constructed in it at a depth of or about BOO feet a tunnel of or elliptical shape through which automobiles were run for the purpose of or ascertaining ho v ho much of or t the e deadly carbon monoxide they gave out the the Inquiry being undertaken to gain knowledge likely to be useful in solving the problem of ventilating the projected traffic tubes connecting Manhattan Island with Jersey City At the pr present sent time in the mine experiments experiments ments are being made in the construction of or chambers for the storage of or helium gas as a reserve supply for war war balloons baBoons underground chambers are prepared for the purpose by smoothing their walls and ceilings with concrete and lining them with metal But it is a a. question what metal is best to use Copper has haIl been tried tred and lead and there are other clements ele cle- I ments meats of or the problem that have havo to be worked out b r No more heartrending scenes scene can about w tM tha imagined than are witnessed or oI oran mouth of or a Q mine after atter the occurrence other disaster under under- an explosion or and MJ lUng ground Crowds of or weeping j flocks of the their women gather attended by latter too y T youn UnS offspring many of ot the to understand what has happened jo For of or days w- w hours it be number or may a not the women cannot know whether or orthey order chit they are widows and ad their orphans In the meantime rescue g the yawning ton pit have gone sone down into of effort brave e in a risking their own lives ea eato C to their unfortunate succor UP broUght ni Later Late bodies of the dead ore are t rou Later to be be Identified one after atter another another- Th who come coma out alive are ore welcomed th r In m n ng note wild cries of or gladness Every Ever g gamut smut of ot human huan emotion is struck |