Radio age (Jan 1927-Jan 1928)

RADIO AGE for October, 1927 41 "ENSCO" choked streets, where there is more room. 11 T ^*ur cm^ren are Soing to consider travel Wall lype Dy ajr as safe> pernapS safer, than travel Speaker on f00t. Moreover health, airships and flying sanatoriums are going to be afloat. Standard "ENSCO" Kit $1 A fid With Hardwood 1U.UU Wall Frame, $11.00 It contains "Ensco" Direct-drive unit, designed and patented by Clyde J. Fitch. Beautifully decorated Alhambra FON-OTEX Cone Material; Metal Apexes; Extension Pin and 12page illustrated Book of In>i m.. -lions for easy assembly of any of six styles of Cone or Roll Shape, Wall, Pedestal or Console Speaker, sizes 24, 30 or 36 inches. You can build it in less than an hour. Static materially reduced — winter results all sumEndorsed by the leading engineers, magazines and newspapers as the outstanding development in radio speakers. Guaranteed to be the equal of any manufactured speaker regardless of price. The "Ensco*' produces the truest tones you ever "The World' s Finest Loud Speaker" Now within the means of everyone. At your dealer's or direct from any of the offices listed below. Send check, money order or C. O. D. Shipping charges paid. In Canada prices are $11.50 and $12.50. Absolute (money back) guaran ENGINEERS' SERVICE COMPANY To the Man with an Idea I offer a comprehensive, experienced efficient service for his prompt, legal protection and the | development of his proposition. Send sketch of model and description, for advice as to cost, search through prior United States patents, etc. Preliminary advice gladly furnished without charge. My experience and familiarity with various arts frequently enable me to accurately advise clients as to probable patentability before they go to any expense. Booklbt of valuable information and form for properly disclosing your idea free on request. Write today. RICHARD B. OWEN, Patent Lawyer 81 Owen Bldgr., Washington, D. C. 41 -M Park Row, N. Y. City r power and ty. Famous ARL Coast to coast reception ! Fin selected, tested parts. Thous FRBE Log and Call Book and New T7ir»TT7 '££1998 The Telephone's Progeny The telephone, most widely used of communication devices,' has become the father of an illustrious family of communication instruments. These include the Vitaphone which furnishes a voice to the motion picture screen; an audiometer to test hearing ; an audiphone to aid the hard of hearing; an electrical stethoscope which amplifies the faintest heart sounds ; a public address system which carries a speaker's voice to crowds of thousands and tens of thousands; and the microphone— the heart of the radio. Electric Darts A tree trunk actually blown to bits by lighting, as though by a dynamite bomb placed inside it, is described by Dr. N. Ernest Dorsey, of Washington, D. C, in a recent issue of the Monthly Weather Review, official publication of the United States Weather Bureau. The tree was struck by a lightning bolt in Jacksonville, Illinois, on the afternoon of April 13, 1927. Photographs made immediately were submitted to Dr. Dorsey by Mr. Frank P. Norbury, a cooperative observer of the Weather Bureau at Jacksonville. The lightning did not strip off the bark or knock off a limb or two; it literally blew the tree to bits. The incident supplies, Dr. Dorsey believes, support for his theory that lightning does not consist of ordinary electric sparks but of "darts" of concentrated electricity, shot down from the clouds like bullets from a gun. Ordinary electric sparks would merely follow the outside of the tree into the ground. The imagined dart of lightning, on the other hand, might penetrate the trunk, just as a bullet would do. Inside the wet wood this electric bullet would cause a powerful steam explosion, disrupting the trunk exactly as did happen in this instance. Airplanes of the Future That the airplane of the future will be large enough to carry a hundred passengers; able to land almost vertically, so that any field will serve for emergency landings ; capable of taking off or landing on the roofs of city buildings ; fireproof, and equipped for flying at a speed of three hundred miles an hour and at a height of 30,000 feet above the ground, are predictions made by Professor Alexander Klemin, head of the Daniel Guggenheim School of Aeronautics, in a statement issued by New York University. Air planes as large as ocean liners, Professor Klemin considers improbable, as the theory of the support of aircraft in the air calls for a limit of size at about the point of a fifty-ton machine with the hundred-passenger capacity. The higher speed at high altitudes will be attained by the super-charger, a device already in use to compress the air before supplying it to the engine. Triumphant! TONATROL" A True Tone and Volume Control Enjoy your radio to the utmost by having at all times the exact volume your mood and taste desires. This is easy if you install "Tonatrol". "Tonatrol" controls volume from a whisper to the most powerful tones — quickly — instantly. A fine addition to any set. Radio experts endorse it. Tonatrol — Standard Volume Control. List price $1.50. Tonatrol— Type W. S. (with filament switch attached) List price $2.00. Dept. 42-B 175 Varick St. New York, N..Y. ELECT RAD I Se Adjusting.' For best performance your rubes require a variable filament control to supply the definite current they need, despite "A" battery variations. AMPERITE is the only self-adjusting and automatic filament rube control that does this. Takes the "guess," inconvenience and unsightliness out of panel rheostats. Simplifies wiring, panel design, and tuning. Prolongs tube life. Orderbyname.Accept nothing else.PriceSl. 10 mounted (in U. S. A.) For sale by aU dealers. Write for FREE "AMPERITE BOOK" of season's best circuits and latest construction data. Address DepU RAW RADIALL COMPANY SO Franklin St., New York DJu "SELF-ADJUSTING "Wuastat