Page:Popular Science December 1931.djvu/141

 AnOK/l ELEMENTARY MECHANICAL DRAWING Now Made Easy To Learn At Home OuroriKinalmethodof teaching with jk I # III Transpiirent Appliances and cut-out — rr^iir.sr) enables you to quickly master the theory of drawing — not a corres- pondence course. Starts right at the beginning, tak- ing you step by step through all the essentials of drafting room practice. Interesting, practical and written bo »nyone can understand it. Written by a man with teaching experience who has spent twenty- five years in drawing and designing. Two books, 6x9, Ber ceably bound, contain all the information. The books will be valuable as a refer- ence when you actually work in a drafting room. The complete Dietzgen drawing out5t furnished with the course will serve you many years. Contains set of drawinginstrumenta.tlrawing board, T-st]uare frcnch curve, celluloid triangles, scale, protractor, drawing ink, paper, pens, pencils, etc. Nothing more to buy. Fill in coupon below, get started on the toad to a future. The total cost of $12.50 is so remarkably low you cannot afford to let this opportunity pasa. JKS" Money Back Guarantee The Cut Craft Company, 183 St. Paul Street, Rochester, N. Y. Enclosed 6nd money order (or check) for $12.50 for which please send me at once your Elementary Mechanical Drawing Course which includes two books, transparent appUances and complete drawing outfit. If for any reason I am dissatisfied after 5 days inspection it is understoo*! that I am to return the Books and Outfit at your expense and my money will be refunded. Name Street City If more information is wanted, check here D fear. earn inLosKn%ccs Come West at Our Expense! For a limited time we are making a railroad fare oiler from any point in the United States to Lo) Angeles. Just think of it! A trip to California with your railroad far* allowed. Quickly Train for Big Pay Jobs Quickly train for Big Pay Jobs in Electricity. Un- limited Lifetime Employment Service. Employers insist on our men Instead of green, half 'baked electricians who don't know what it's all about. You need good training to earn Bio Pay! Don't Worry About Moneyl We'll Help You! If you are short of money, we'll help yoti. We help you secure a part time Job to earn living expenses while learning. It's Easy at National! Short, condensed training in our Million Ooltar Practical "School of Shops* . . . instruction on the most modern equipment money can buy . . . with the country's best staff of expert, experienced in- structors. No previous experience needed. None too old or too young to learn. Start any time. WRITE TODAY! We'll send you the full story about Rail- road Fare Offer. Unlimited Em* ploymeni service, ete. New Book sent FREE. IREE BOOK IfATlOKAl p iBCTlUCaiffHOaL Dept. 127-E, 4006 So- F)j;uc[ua Sc-. Los Angdn. California STAMMERING You can be quickly helped if you stammer or stutter 1 1 ENOW, bpcause 1 rollcted myself after Etammerini; m relief — has interested thousands, many of whom have m permitted me to help them. Full story of my success- kj fu' M ro: ^ II — lias inieresiea inousanus, many oi wno permitted me to help them. Full story of my l ful elTorts told In 27!i-nflcc book. Sent anywhere for in itnts. B. N. BOGUE, 11896 Bogue Building, 1147 North Illinois street, Indianapolis, Ind. WHY SEAPLANES FLY WITH BULLET SPEED (Conlinufd jrom f>(t);e ,^o) I was headinp back alonv: the coast for the harbor when I noticed a patch of ruffled water near the shore. Sheer 1,000-foot cliffs rose from the sea at this point. Near the disturbed water, a nar- row chasm, like a knife cut, had been worn throuph the bluffs by a mountain stream. From this wild ravine, narrower than the span of the Dornier's wines, a little breeze was blowing, produced by cooled air flowing down the cut. I swung the big boat toward the cliffs, opened the two 500-horsepower motors, and thundered straight for the mouth of the gorge. Out of the tail of my eye, I saw the mechanic grab hold of his seat, snap his head around, and look at me as though he thought I had gone crazy. The cliffs loomed higher and higher over our heads. Our speed w'as increasing with every foot. As we hit the ruffled water, a crash seemed inevitable. Then the breeze, striking us head-on, lifted the ship on its step. In a skidding half-circle, I swung to the right and headed out to sea for the take-off. In a water plane, you can make a turn like that at high speed. On a land plane, it would wipe off the landing gear. In skimming along the water, a seaplane or flying boat rides on its step, sunk only a few inches below the surface. So it is only the top "skin" of the water that resi.sts sidewise movement, and this is insufficient to do damage. For this reason, a seaplane is able to land without difficulty at right angles to a current or while drifting sidewise in a cross wind. WHEN Glenn Curtiss took off from the water near San Diego, Calif., in 1911, in the world's first seaplane, his machine was equipped with a single boxlike, flat-bottomed wooden float. A little later, the hydroplane step was introduced, increasing its efficiency. The next advance was the substitution of a V-bottom for a flat one. In landing, the knife edge of the V cut into the water and reduced the shock. But suction around the sides of the first V-floats threw spray into the propeller and cockpit. So spray-strips, like automobile mudguards, were attached to the sides of the pontoons. However, a new type of V-bottom soon made them unnecessary. By curving the legs of the ' inward in the form of two scallops, the spray-producing suction was eliminated. The latest floats, such as were placed on the Lockheed monoplane flown to the Orient by Col. Charles A. Lindbergh, have a "double scallop" bottom. This gives a minimum of spray in running through rough water. The two characteristics of a good pontoon or flying boat hull are "clean running" — that is, throwing up little spray — and having the least possible amount of resistance in travel- ing through the water. At Cowes, England, in 1925, I tested a huge multimotored flying boat that had an inverted V-bottom like a seasled. It gave clean running in heavy seas, but its water resistance was so great that the design was abandoned. The greater the water resistance, the greater the power required to get a ship into the air. BECAUSE of this fact, my transatlantic plans were almost wrecked by one of the strangest cases of added resistance on record. .t the .■zores, we made our final tests and found just what the Dornicr would lift. Then there was a month's delay, repairing the radio and waiting for good weather. A perfect day arrived. Wc filled the tanks, stored aboard our equipment, and charged out into the .tlantic for the take-off. The ship wouldn't rise. (Continued o» />ii,i;f i.^S) BIC OPPORTUNITIES ^AVIATION DECEMBER, 1931 Avi.4TION Is J-_ growing rap- idly. During the past year transport operators increased their activities over 2 00 'A. 3,007,670 people traveled by air. The total length of air mail lines in the United States is now 29,589 miles. Every 24 hours 84, 771 miles are flown. The growth of Aviation offers great op- portunities and big pay to aviation me- chanics, ^'ou can train for a good posi- tion at one of the Curtiss-Wright Aero- nautical Training Schools — leading .Avia- tion Schools in the United States. A new .Mechanics' Course provides the best preparation for a career in Aviation that you can possibly find. The sound, practi- cal e.xperience you obtain in this Course applies towards a United States Depart- ment of Commerce airplane and engine mechanic's license. Train to be an aviation mechanic. No other industry offers a brighter future, more interesting work, or better pay. Curtiss-Wright Aeronautical Training Schools are located at New York, Chi- cago, Los Angeles, Baltimore, Boston, Pittsburgh, and 25 other leading cities. If you are looking for a real opportunity and a chance to make big money, mail this coupon for complete details about the Curtiss-Wright School near your home. CURTISS-WRIGHT AERONAUTICAL TRAINING SCHOOL 29 WEST 57th STREET NEW YORK CITY Curtiss-Wright Aeronautical Training School 29 West 57th Street, New York Ciry Please send me complete details about your new Aviation Mechanics' Course. Name Address City Stale Age 237
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