Air Wonder Stories, December 1929 — page 86: what you’re looking at

Machine-transcribed from the original scan — historical spelling and the odd misread are preserved.

AIR WONDER STORIES AVIATION FORUM (Continued from- page 561) A Watch as a Compass Editor, Aviation. Forum: ; T have heard that itis possible to use -a watch ag a compass, fll, you please tell: me how it can be done? JERRY NOONAN, Ay in, c/o paDR hy Red Star Ranch, New Mexico, (in- order to _us¢ a watch as a compass one must consider the watch as a twenty-four hour astronomical chronometer. In other words, on such a chronometer the hour 24-.would cor- respond to noon and the: hour of 12 would be midnight, So, while the hour -hand- on: our watch moves sround-the face pn ae hodrs, that of the astron chronometer woul move around the face once in 24 hours, This is made clear in- the illystration- accompanying. Now, suppose our watch registers noon, and we wish to -ascertain our directions, If we face the eun, with the- hour hand toward the sun, it is pointing approximately ‘south, —That- will be.-trne also for our watch, for -at noon the hour ‘hand-on-our-watch is at’ the ‘same point on the dint-as on a. 24-hour chronometer, Again, suppose it is-2 p. mt; our 24-hour chronometer would show: the hour. hand at 2, or 1/12th of the way around the face, On -our watch, how- s\urommanmeremesetintit Hlustrating how -a watch canbe used asa compass, At 2p, m ifthe hour. hnnd_of a 24- hour— chronometer is pointed. toward the sun—the-num- ber 24 would. indi- eate south. Using a watch with 17 number 1 be pointed toward the sun at2 o'clock and-12 would: in- dicate south, yates Uy ever, the same relative position will be only at the Ggure 1, which is-also 1/12th of ‘the dis- tance around the dial, while the. honr.hand “is at 2,-which is. 1/6th of: the way around, While, therefore, on. our astronomical_ chronometer. the sun is always in Hne with the< hour. hand— when 12-is-to.the south—on a common watch the: sun is only half as. far from south as the hour hand ‘indicates. erefore, a convenient method-is- to hold the hour-hand on the sun, and-take sonth as the point half-way between the hour -hand-and 12 {this-is simpler than boldin e- sunt half-way between the hour~hand--ani 12, but comes ‘to the same thing]. This oan be done, of course, only when the sun is visible; and tt does not allow for the facts, that standard time js sun time only in places, and that the sun is exactly south at noon- on only four-days of the year. For a rough indica- tion, however, it~ will-serve well enough, at most times-and places. —Editor.) Rocket-Propulsion Engineers Editor, Aviation Forum: T have several questions: + Just what is a rocket-propulsion engineer? I have for a long: time - been interes in so experiments: going on in Germany, would like to take this type of work for. my life’ yocation, 2. What. schools offer such a. courge? , 3.1 believe I understand bow liquid oxygen is-made, but it-is beyond me how Aree use it in rockets, Can 4 you chelp me? ANKEEIN SMITH, re 3, Tower City, Pa. ‘ocket arbadisises has not f Box I, We believe that yet reached the stage where it has becomé-a profession What. the newspapers may refer to as ““rocket-proptlsion engineers” are. engineers who have made the: study of rockets their ty. 2, No- schools offer courses. in the subject; but Professor R, -H;- Goddard of Clark Uni- versity, Worcester, Mass, is the leading Amer- aT Pe oroatly- aanleeeia ta i - You" probably--undeérstan it oxygen is the portion: of the, air which serves to barn? a substance; in the pure form, it bringa-about 0 rapid— ignition with the: release of. such tre- mendous energy that it causesan explosion as with ‘the union of oxygen-and hydrogen, ‘I'he reason for using. liquid oxyg¢n. is, chiefly, to get-the oxy; In a@-concentrated form; tho sag would -require -too much- space, and too much weight for the containers, to be efficient. Further: more, by-having- it~<concentrated, greater ex- plosive power 18 obtained, The oxygen, in ractice, ignitesa concentrated fnel, such as enzine- or alcohol or’ a—combination- of these; and the gases formed rush through the exhausts at-a: tremendons -velocity. The reaction to the force of the exhaust propels the plane for- ward.—Editor.) PAUL’S COVER ILLUSTRATIONS readers have praised the work of the great artist Paul— and thousands have asked us to sell them the original covers—but not until recently have we been able to satisfy this demand. Now, reproduction orig- inals in water colors of Air WONDER STORIES can be had at an astonishingly low price by our readers. These covers are exactly the same size © as the artist’s painting (18’ x 25’) and made with the same 13 full colors that were used in | making the original. There is » no printed matter whatever on the cover as you will note by the Young lady holding a full-size reproduction original—which is four times the usual magazine cover sise—exactly as it will be mailed to you, T HOUSANDS of tet eB) el. eae Reproduction Originals in Water Colors illustration in the center. Covers are made of heavy flexible mat board that makes them well de- serving of a frame — a suitable picture to be hung in any home, class- room or. clubhouse. The subjects, while both edu- cational and: scientific, may appears fantastic now but in future years willbe.a reality. Predictions of Jules Verne, H. G. Wells and others that have come true— actual hap- penings in everyday life. Surely you will be happy to own one of Paul's full-sized: cover illustrations—tell your friends of this oppor- tunity. Send only one dollar = and the reproduction original will be sent to you, postage prepaid. anes and for- eign, $1.25. Prepaid STELLAR PUB. CORP. 98 Park Place, New York, N. 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