Judge — March 3, 1923 — page 26: what you’re looking at

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

The E. L. Rice Mathe- matical Chart Revolu- tionizes Mathematics. Its Tabulated Informa- tion Would Fill a City Library. Solves Mathematical Problems at a Glance. This chart gives you tables of decimal equivalents that would require a library of books. It gives you tables of inte calculations that would require volur It gives you tables of square roots, cube that would require tables of their p uire a like library trigonometric solut: require a and other roc rary. It gi that would r algebraic soluti of conversions v other conversic gives yo pulated informati fill a Carnegie library with tab Practically every problem solvabl tically is solved at a glance on t do not need to know how to them mathematically. The chart knows this, it does this, and you need not know the why and wherefore. ter a few minutes’ study of this chart, for instance you can solve ‘oblem iti ning hic solves problems from simple arithmetic up through trigonometry. Multiplication of small or numbers at a glance. Fr sive and be is likewise nid Algebraic equations f utions all yc at your subject property. You ean fr methods. CHARTS WITH INSTRUCTIONS 16}4-inch on book paper, 50 cents; on ledger paper, $1.00. 34-inch, $1.00; 48-inch, $25.00; 6-foot, $50. foot, $100.00. Charts me size on celluloid-coated aluminum three times above prices. E. L. RICE Machinists Bldg. Wash., D.C. who derive larg- est profits know and heed certain simple but vit fects before applying for Patents, Our book Pa atent Se fives thi Write Lacey ESTABLISHED 1809 | trical impulses, the bre We Pay $7 a Day onderful invention, | The EA" Goes ore then meechines costing 10 times its price. Orders our agents for over a send a weak soaking frocs #7 Easily carried with you'anywhere. Built in just like a suitcase. Fully guarant Low price. to Take Orders No collecting. Pay you every day. Get star Territory en, Write for PERRY-LUDLOW CO., $.598 DAYTON, oO. “at once. Radio Department Conducted by William H. E ted to turn to us for ailrice regarding the selection. installation, operation and care of radia Address al E In case an answer by mail is desired a two-cent postaye Subscribers to Juvax: are i receiving arte. No charge it made for this service, New York, giving full name and ezact street address. should be inclosed. For information concerning the technical details of construct on, Ph.D. letters to Radio Editor, Juvax, 627 West 43d Str nn of receivers and tranamitters the reser is referred to the several very excellent technical radio journals which are to be found everyichere today, New Microphone Makes Perfect Broadcasting Possible 4 vou been listening to KDKA, Pittsburgh, recently? If so, you have undoubtedly noticed the unusual ¢ and purity of this station’s voice. There is a very good reason for this great improvement. in ». KDKA is now using a micro- phone of an entirely new type. The microphone is, of course, the de- vice that receives the sound waves in the studio and changes them into electrical impulses for radio transmission, If it is able to change all of the sound waves reaching it into exactly corresponding elec- deasted speech and music will sound precisely like the original; but if this transformation is not perfect, if the microphone is able to handle only part of the sound waves and lets the rest get by it, the result is the distorted, tinny signals that we are only too familiar with. The essential part of every microphone now in use (except at KDKA) is a diaphragm—a thin disk of metal which operates by being vibrated by the sound waves. Every- one knows, however, th music as generally broad- casted is not perfect, and this is due to the fact th no disk will vibrate in. pe fect sympathy with every possible sound wave. It may do well with low notes and fail on high ones, and and vic or it may be satisfactory with — the middle register and be very poor with the extreme high and low registers. versa; HE NOVEL part of KDKA’S new micro- phone is that it has no dia- ph m. In its place is a minute electric discharge which flows between two points set within a small fraction of an inch of each a stream of ma ss. It can be by sound waves transform these into electrica impulses. But being non- material, the discharge has no perceptible weight, in- ertia, or stiffness, and in consequence it responds with equal readiness to all sound waves and makes it made to vibrate and will vibrations ey are produced. re not as yet able ve these sounds per- » however. Your re- ceiving apparatus, no matter 24 Ye day's catch. the how good it may be, is still far from per- fect itself, and hence it is bound to distort to some extent the signals it receives. B. with perfectly modulated radio waves striking your aerial, you are justified in im. proving yourreceiver toany desired extent, which is not the case when the received messages are distorted to start with. The new microphone is known a Thomas Glow-Discha its inventor, Dr. Phillips Thomas, research engineer of the Westinghouse Company, and from the fact that the discharge one of its terminals to glow. It will un- doubtedly be put into service in several of the larger stations in) the near future. Non-interference Night Tue is considerable demand for a “Silent Night” in each district once a week—that is to say an arrangement whereby all the stations within New England shall shut down, Monday nights, those in New York and New sey on Tuesdays, and so cross the Continent is to permi radio audience to hea distance stations without local interference. The plan would be wel- comed by all owners of long- range receivers, but it would work a hardship on the much greater number of crystal detector owners who would be deprived of radio service on the Silent Night for their district. A much better plan has _ recently been suggested by Mr H. P. “Father of Broadcasting.” His idea is to hold a “Non-interference Night” each week, when ail stations will be shut down with the exception of about twenty, carefully selected with regard to wave length and Jocation, so that they will effectively cover the entire country but without interference. Under such circumstances, listeners on the Atlantic Coast could un- doubtedly hear the Rocky Mountain, and possibly even the Pacific Co tions, and vice 5 number of non- interfering lists, consisting stations for the most part, could be drawn up: and by using one list the first week second list’ the next