Radio age (Jan 1927-Jan 1928)

RADIO AGE for January, 1927 The Magazine of the Hour 53 ¥• f Samson Dual Impedances v give good tone quality — and volume Weak signals are not over amplified; there is no blurring or distortion on loud signals. Price $5.00 each Without change of wiring simply replace audio transformers in your radio set with Samson Dual Impedances (Donle System) to get: Very good tone quality and unequaled volume. Aemher SAMSON ELECTRIC COMPANY Sales0ffi RMA Manufacturers Since 1882 all large MAIN OFFICE, Canton, Mass. FACTORIES at Canton and Watertown, Mass. Our Book — "Audio Amplification" — the design manual of many radio engineers — has much original information of greatest practical value. Price 25 cents Theories of How Prehistoric Man Discovered Fire CONFLICTING theories of how prehistoric men first learned about fire are affected by an investigation made for a quite different purpose by the United States Forest Service and just reported in the Monthly Weather Review by H. T. Gisborne. Some students of prehistoric man assume that the first knowledge of fire came from volcanoes; others ascribe it to forest fires started by lightning. The volcano advocates have urged that lightningignited forest fires are too few to have served as such a general cause. Mr. Gisborne and his assistants are charged with the duty of watching for forest fires in a portion of the northern Rocky Mountains. So far from being a rare occurrence, they find that during 1924 lightning started 51 per cent of the forest fires and in 1925, 81 per cent. Lightning constitutes, therefore, the greatest single danger to the Please Write For Booklet— It Tells How To Build a Better Set f Than You Can Buy* Most Practical and Successful Circuit Yet Devised— It's New Yet Not Revolutionary Proven By Test — The Outstanding 1927 Success HENRY-LYFORD RECEIVER Has been endorsed and approved by Radio News, Radio, Popula Radio, Citizens Call Book, Radio Review, Radio Mechanics, New York Sun, Boston Post, Christian Science Monitor and this magazine, read about it in the January issue of the Radio Age. IT'S A PLUG-IN COIL RECEIVER WITH A DELIBERATELY UNBALANCED CIRCUIT HENRY-LYFORD receiver has been tested and compared in many laboratories with practically every quality set now on the market with this result — were a manufacturer to build this outstanding circuit of the year it would easily come within the $300 class. This NEW circuit with interchangeable coils has a wide wave length range of from 3 7 to 550 meters permitting you to tune in where the ordinary receiver NEVER GETS. Build it and you will have a better set than you can buy. It's As Near Perfect As They Come and EASY TO BUILD If your dealer cannot supply you, order direct UNIVERSITY RADIO CORP. 50 Park Place, N. Y. C. Please send me booklet describing in detail full particu-| lars of the Henry-Lyford. Name _ i Street j City and State _ _ | Complete Parts All parts fully guaranteed and neatly packed including blue prints. 69s-2 forest. Actual records of light ly familiar with such fires, and ning fires confirm, therefore, thus in position to observe the the contention of those who habits of fire and to learn, by have maintained that primitive the accidental cooking of ani man must have been continual mals in the burning forest. Mention Radio Age When Writing to Advertisers.