Evening Star Newspaper, March 28, 1926, Page 79

ILLUSTRATED FEATURES MAGAZINE e he Sundiy Staf SECTION Part 5—8 Pages BY LEE PO ELEPHONF, through the Potomae R sible Yes,” was assured by head of the Radio and vision, Bureau of E States Navy; “alr made with somc Comdr. Iooper I with the developm ashore and afloat, for ably s the foremost authority in mol Navy on the subject of radio com munication ‘ | ication s of the| it pos € the interrogator S. C. llooper, | Sound Di- | oring, United | ive been | suce assoch radio, nd prob- Comar gree ¢ s been of vea ted | both Naval experts predict the under: telephone soon will be a ctor as the instrument used the office or home. It is significant that favo: ports should be mads on experi- | s in_developing con trivance for tr volce simul of the fifti Ale tion At tomac twe Nav carried on exy the super tific term for This this lates trument communi. frequencies, frequenc reflection alled. a 1tes Communic heno ed by by echo high \tion lo by e origin of ec mytholog Vv was of Earth and Alr seus, and at his death In nymph who loved Nar pined away until nothin her but a ce, whic mortality wander world repe reached echo after day there the world, An extraol discovered hy Ve This the myt mar ngevin at | nsation et d’Ap- | Mecniques. P recently | used throt ephone discov®| the | the ery pract world h new super wation perfect have rtion and | heen fou waves and that of the oce to all. THE early 1 v i wention hased specinl vibratol which water to Washin 1917 in marine problems na tlons. Associated with Prof. Is vin in his invention 1 Chitowsky | & Applications Me Towever, an apy echo has bee 5 by the Cun Cartier, states th drographtc B United States the subject of on the waves, ci insmit then were first n in nec umicated of ti-sub; ¢ sounding trial veving vessel al Hy In 1918 the oncentrated on marine research by | means of sonic subagueous reflection and utllized the powerful oscill of the Fessenden type. Briefly, super-sonics deal with the sound frequenc 1,000 per se ond. The appa of mosaic of quartz crystals sandwiched in be- tween two steel plates and high voltage current is applied to the in gide plate which causes the erystal to expand and contrac the same fre- | quency. The vibratior itted to the water 1 astie or compression waves which travel in a | beam. | The principle is one of direct sound. This system of a triple plaie. quar fnserted between two plates of steel, already has been utilized in order to establish standards of wave-length It is evident that thus a system is available which has a definite proper period and which, when excited, reaches & maximum of resonance when the frequency which excites it is equal to the frequency proper to it. | When efforts are made to deal with the problem of the working of an gan such as the plezo-electric indwich in connection with an oscil- lating electric circuit, in order to terize the working of the aerial” in radio, to introduce the con- ception of the energy which it bor- rows from the osci nt and to characterize it by nce of radiation the super-sonic waves emit- ted are sald to constitute energy derived from the quartz. ppa- ratus may be compared te nce introduced into the circuit and would likewise have a certain resistance of radiation MUCH the emploved ns e is up i x- same process as that radio used for transmission and reception through water. At least this theory is ad- vanced for explanation of most types of the super-sonic device. For instance, a set of valves pro- Auces electrical oscillations in a eir- cuit tuned in accord with the fre- quency of the super-sonic waves to he emitted. There is a lamp valve with three electrodes (triode valve), continuous current generator, conden ser (voltage regulator), condenser of oscillating eircuit and a grid-plate transformer. This part of the hook-up is familiar to every radio enthus The tog circult. fed by ction of the valve, acts by induction on another circuit in resonance with it. Coupled in parallel, this eircuit fncludes a variable ofl-condenser to regulate the frequency and a quartz which allows the electric ations to be transformed into super-sonic waves of the same fre quency. The same quartz condenser efves the super-sonic waves and transforms them into electrical oscil- tions in the oscillating circuit. An mplifier is connected to the termi- s of the quartz condenser and the detection of the super-sonic echo by the usual methods of radio is thereby obtained But it is essential first to determine the depth of the water. This is found by lowering a sound bathometer near the surface of the body of water. A | sound impulse is reflected back to that point by any submerged surface within its range of generation Dr. Harvey C. Hayes, research phy- | sicist of the naval laboratory, at Bel- levue, D. C., who has been making ex- periments on undersea communica- tion for the United States Navy since the inception of the theory, in 1922, completed the development of an ap- paratus for obtaining ocean depths by an instrument called the sonic depth finder. A report of the Hydrographic Office states “‘successful tests were made and excellent results were ob- tained with this apparatus by the in WASHI SUNDAY MORNING, MARCH FICTION AND HUMOR 28, 1926. Echo-Sounding Principle Employed in Under-Water Telephone Communication—Hook-Up Similar to Radio—Prof. Langevin of France Is Inventor—Successful Tests Made at Mouth of potoma'c—-Experts perfecting Method at Naval Research Laboratory, Bellevue, D. C.—Human Life Safeguardecl at Sea Through Use of Super—Sonic Telcphone—Ocean Depth Finder Modern Development W}nch Has Been Of Great SB!‘ViCC. Dt.Harvey C.Ha e Naval Rese Mcfi,ql_a, boralor messages through the water Placing Undlerseas te sound transmitter used in fephoning i 0 s, Superintendent of Sound Divisionof Yeceiving telephone s U. S. §. Stewart on a voyage from Newport, R. 1., to Gibraltar, and from Gibraltar to Manila, P. 1.” The report continues: “The design ot the sonic depth finder Is based upon the theory that a sound impulse emanating from a point near the surface of a_body of water will be reflected back to that point by any submerged surface with in its range of propagation. This the- ory applies particularly to the sea bottom. ““A vessel equipped with some form of sound transmitter and recelver, passing over a sea bottom of greaf depth, may use this apparatus to measure depth approximately by send- ing out an impulse with the trans- mitter and measuring with a - stop- watch the lapse of time before the echo of that impulse is heard in the receiver. A highpower vibratory sound transmitter is used’ with the sonic depth finder and a sound re. celver which determines direction ac- curatel All that is necessary is to know the velocity of sound in water and to perfect some method of accurately measuring the time from the moment the sound is produced till it is heard again, is reflected back. This accurate measurement of the time interval is now perfected. “Considering the velocity of sound to be 4,800 feet, or 800 fathoms, the distance the sound travels to the sea bottom and back will be equal to the number of seconds, shown on the stop watch, times 800 fathoms. The depth would be equal to one-half of that amount. “Experiments have been conducted with a patented - device which con- sisted-of a constant speed mechanism which would be set in motion by the out-going impulse and, by means of |a delicate relay System, was brought to rest by the received echo, thus in- dicating the time interval desired.” . EEEE HE International Hydrographic Bureau, describing the Langevin method of undersea telephoning and telegraphy, in part, states: “In principle, if we consider the problem in its general form, it is a question of transforming electric osctl- lations into elastic. oscillations. Na- turally, every phenomenon which brings into play mechanical action of electric_or magnetic origin can solve the problem. “As soon as M. Langevin thought of utilizing the piezo-electric prop- erties of quartz the problem of emis- sfon and reception of super-sonic waves and of their application to navigation for the detection of sub- marine obstacles and for sounding vas solved. plezo-electric phenomenon, which was discovered in 1880 by Pierre and Jacques Curle, represents one of the most remarkable examples of the power of thought on scientific work, they discovered the phenomenon, which represents exactly the best means which can be selected, as ex- perience proves, between electric phe- nomena and elastic phenomena. !‘Piezo-electric properties are met with In certain crystals, for instance quartz, which is used and in_nature ordinarily appears in the form of hex- agonal prisms * * * If the combi- nation so formed be compressed, the armatures will be electrified and a current in a definite direction will be obtained; and if the pressure be re- leased a current in the reverse direc- tion is produced. This is the direct plezo-electric phenomenon, The same arrangement can be-used to detect the arrival of elastic waves. If the two armatures of the condensér are placed, one in contact with .the water and the ether insulated there- from, and super-sonic waves reach them, the variation of pressure in the water periodically compresses : the quartz and produces currents.. If a self-induction be inserted so.that the period proper to the electric circuit is exactly the same as that. of -the incident waves, the current. which tends to be produced will he amplified by resonance, and an. electric oscilla- tion ‘will have been produced . with super-sonic waves, due to the piezo- electric properiies of the quartz. “If the - two extremities of. the quartz condenser be connected to an amplifier ,of the same type as that which is used for wireless, the arrival of the waves can be detected by the same process of detection as is used in wireless. It is as though the whole formed a submarine ‘aerial’ sensitive to elastioc waves as an ordinary aerial is sensitive to electro-magnetic waves, and this system replaces the micro- phone with advantage. for it is after having foreseen it that | Trangmission app WIDE WORLD PHOTOS. - aratus wsed, orvPolomac barge in developing underwater telephosne. | “As soon as Prof. Langevin had tried it, a sausfactory solution of un- dersea communicdtion was found. “During the course of operations it was necessary to be guided constantly by the intensity of the super-sonic { emissions produced, and for this pur- pose a convenient and valuable proc- ess based on the existence of ‘pressure of radiation’ was used. Pressure of radiation i= due to the fact that any radiation which is not ‘material but consists of a modification, when prop- agated through matter, striking an obstacle exercises pressure thereon. “A luminous ray, ih fast, exereises pressure on any obstacle which it en- counters. The effort exercised on each unit of surface of the obstacle repre- sents the density of the energy of the radiation on the front of the obstacle. “It is remarkable that this same property exists In the case of elastic waves. 1f a flood of words be directed Lowerin water {hgou.qk, hdd sound barge | [ | waves does | sound, transemitter into the pening in theNaval erted on this obstacle. “When this radiation is directed onto a pallette suspended by a tor- sion wire, the pallette, if its thickness be appropriate, is pushed by the ultra- sound and the torsion of the wire per- mits the measurement of the power emitted. Thus the results obtained during the course of experimerts in the transformation of eletric energy into elastic energy can be checked continuously. “Under the conditions which exist when the plezo-electric oscillator (singing condenser) is used, it is nec- essary to produce periodical variations at the same frequency as radiation is required, and these variations corre- spond to amplitudes.’ Although the - original work of Lahgevin in super-sonics was:concen- trated on communication and detec tion of subimarines, the peacetime value ‘of the apparatus for sounding the depth of the sea was apparent, and this feature has been rapidly developed since the close of the war, * koK K IT is pointed out that In connection with marine invention of most de- scriptions it is distinctly noticeable that the majority of nations are treat- ing such matters as confidential. This, no doubt, is the result of the war, in which it was obviously essential to keep all new inventions as. secret as possible: It is thought that an additional rea- son for mot publishing such informa- tion may be due to aversion to the publication of imperfect data. The necessity of safeguarding the com- mercial rights of these novel forms of apparatus may also be a reason for whitholding information concerning their details. In spite of the results obtained by means of the Langevin apparatus, comments the director of the French hydrographic service, this system is too complicated to be taken into gen- eral ‘use. The French hydrographic service continues: ‘“‘Besides, we are certain that we shall succeed in sounding by means of much more simple acoustic arrange- ments, having discovered that a light blow with a hammer on the hull of a | ship transmits to the water sufficlent sonorous energy to make the echo against an obstacle, pressure is ex-*’from the bottom of the sea audible in depths of 110 fathoms. The scientific research department of the French navy is now engaged in the perfec- tion of a sounding apparatus based on this principle. “In greater depths, for the last year, we have been using an acoustic sound- ing instrument devised by an officer in my service, which employs the sound made by detonation.” On the subject of the phenomenal method of undersea communcation, the Italjan hydrographer writes: “This office is aware of the difficul- ties formerly experienced in taking soundings by indications of a manom- eter. These difficulties may be con- densed into the fact that the inflow of water into the tube which is drag- ging along the bottom is not constant. For this reason it is difficult to sep- arate the increase of the pressure of the air in the tube from that caused by the vertical column of water which flows into the tube and assists to form the pressure at the end thereof. “It is known the the difficulty has been overcome already by the German navy by introducing special apparatus consisting of a capillary tube which has, near its open end, an air reser. voir. Specimens of this apparatus were found in the ships which be- longed to that navy, and one of them is in possession of this office at the present time."” * ok ok ox F. SIRKS, an engineer under the * auspices. of the Nautical Insti- tute and Museum at Rotterdam, de- scribes the Behm depth indicator as follows: “The instrument serves to measure the depth of the sea by sound, viz., by observing the difference in time be- tween the detonation of a sound signal and the return of the echo from the sea bottom. The whole instrument can be worked from the bridge of a vessel and consists of a rifle, loaded with a detonator signal, two mlicro- phones fitted, below the water line, to the side of the ship, and a recorder on the bridge. The rifle is fixed to the side of the ship above the water line, and can be loaded from the bridge by a pneumatic tube and fired by electric contact. “The explosion is received by the port microphone, which closes a con- | reflects a | divi | reefs. tact of a small motor cular mirro shaft on the angle of r on of mirror being 90 de heam o ded in a . )n the return of the bottom it is rece board microp electric contact brake, instan of the mirror be immediately corder on th position of the by the mirror ¢ depth: photo; been patented Owing to th new procedure the se: tion is increased enoi portance of which considered since it is arding human life the employme not sol of navigation, particu occur when of navig: n In many signal or teo BRena: Bt the echo ved in the ch, throu engage topr e actual depth read of m the re bridge by noting the f light reflected For great recorder has aphi matter of safe t sea is ases it 1= import se of dete 1 ohs or the di nining of the sea in order unexpected or even the presence of fl which escape the ¢ dangers—i ence of w Even the - meg | mitted | The question | gation, of tr waves h water, whether it be for at a distance or for the d reflectic -eiving an echo of 4 bstacle, is ex ant fo nav{ Science, thousands of to the world for efficiency of mank the to develop: use another of its “brain child Many eminent scientist Langevin France, Messrs senden, 1 Morecraft with Train Telephones. T SCHMITZ New York of the Germa has announced that telephony has proved so successful the express trains between Berlin Hamburg that other trains are to equipped. representa in | roads, i on e be “Despite the noise inseparate from a train,” he savs, “and despite, the constantly ch: & distance ¢ which a three-minute radiophone cor versation carried covers some three m | talk—the audibility | be desired. The conn i|> made quite as speedily |case of ordinary I | “To receive a « |on a swiftly movir | dust as easy and called to the telephone by in a hotel lobby. ‘Mr. Brow a neatly uniformed youth passes through the cars of the Berlin Hamburg express speed snow-covered plains many. Mr. Brown lo newspaper and notes the le the young man's cap: ‘Tr Ltd.’ as being a page b in Teleph e call for you from Ber- the young man. Mr. Brown follows him through the corri dor of the compartment coach into the next car. At one end is a compart ment marked telephone station, pre- sided over by a competent ‘hello’ & Near her is the customary telephone booth. He enters, and presently he is talking—from a train racing with a speed of a mile a minute—with his friend in Berlin, or in Hamburg, as the case may be. “Not on passengers on the train can be called up by their friends as illustrated in the case of Mr. Brown, but the traveler can likewise call them from the train. It is hardly necessary to add that telegrams can be and are transmitted telephonically to the pas sengers or from the moving train to. ¢ city in Germany. The charges or this service are but little higher than for ordinary long-distance calls." The train telephone station, it was explained, represents a combination of srdinary_telephony and wireless teleph- ony. There are three sending sta- tions for the Berlin-Hamburg route, one at each end of the line and one half way between the two cities. The trains have an, antenna extending over the roofs of the cars. The first experiments in train telephony wers made seven years ago. = Sht;rt-\Vave Power. ATORE MARCONT has explain- ed how he and his engineer, Capt. Round, have succeeded in sending wireless messages by day to the Argentine by the use of power of only one-fifth of a kilowatt and a wave length of 15 meters. This important discovery, for which Senatore Marconi gives his engineer full credit, brings appreciably nearer of world-wide commercial less telegraphy t opens the way for a twenty: four-hour service with any part of the world at a much cheaper rate than has hitherto been possible,” he said, “‘because much less power will be neceesary. ecent discoveries have disproved the old idea that to get greater dis- tances it was necessary to use longer wave lengths and higher transmitting power. It has been known for a long time that by using a 60 or even a 40 wave length one could get the Argen- (tine practically all night, Zut not by da We had indications that a shorter wave length would go through better by day, and we tried it with very sat- isfactory results. “The discovery is the more impor- tant from a commercial point of view because it opens up greatly increased | facilitles for communication during the business hours of the day.” The tests made by Capt. Round at Chelinsford revealed the existence of certain qualities in the ether that may be utilized, by the use of short wave lengths and much less trans- mitting power, to communicate ¢ver distances covering the whole globe. »