518 Anti-Swell * Anti-Pain Anti-Tired Anti-Perspiring a Com We are showing | some very attrac- tive necklets of GENUINE AMBER The price of this very at- tractive Ornamental Bead is steadily ¢oming down. Some of these Strings suitable for Young Girls, are priced as low larger, greater up to "FOR SALE SAN Frame, 6 rooms, toi- let, central, deep lot. Frame, 6 rooms, toi- let, electric light and as .... gas. EL \ Frame, 6 rooms, Others $3 electric light, gar- and in den. ; lengths, Frame, 7 rooms, $2600 electric light, gas 2 and furnace, central. By 7 rooms, frame, 3- $2800 piece bath, electric light. Bateman's Real Estate (Aaa BROCK Och br. RINUSTON tm | A REDUCTION The Civic Utilities reduced the price of gas for cooking a short time ago. We have a Cas Range to meet every pocket. (A) 3 Burner Low Oven Gas Range $22.00 3 Burner Low Oven Gas Range-- large burners ...... ... ... $30.00 3 Burner Low Oven Gas Range-- * large burners, N. P. trim . . . . $33.00 4 Burner Low Oven Gas Range-- large burners, enamel top . . . $40.00 * 4 Burner Cabinet Range, N: P. top' ' and whiteenamel ..... .... $85.00 {| McKelvey & & Birch, Limited Fitters and Plumbers, Jobbers of Plumbers' and pe Supplies,o Stoves, Shelf, Heavy and Howse Furnishing Hardware, Tools, Ofis, Be : Supplies, Sheet Metal and Tin Werk; Kleetrie work) Painting and Paper Hahging. 7pecial werk of all Minds undertaken. i ab WE SERVE GOOD MEALS Good meals sorved to your liking. EVENING FFARTIES given first class attention. THE VICTORIA CAFE 854 King Street. Blug Lee and Gan Lee, Props. Telephone 762 THE DAILY BRITISH WHIG PROBS: :+--Friday, southwest winds, mostly fie and warm. How A Tube Detector Works. 1. By Grid Bias. Most readers of "Current Radio" do not seem to be acquainted with the fact that there are two com- mon methods of obtaining detection with a three-element vacuum tube, por how detection in each case is accomplished. It is the purpose of this article to describe one of the methods--detection by grid bias-- and tomorrow we will describe the other--by use of grid condenser and leak--which is the more common practice. Remeniber that the incoming sig- nal is an alternating current oscil- lating at super-audible frequencies. In order to make these signals oper- ate a pair of headphones, we must convert the alternating current into direct current, and that is what the detector does. Let us consider Fig. 1. Do not be alarmed by the appearance of ap- parently complicated "curves" be- cause they are really quite simple tc understand once the fundamental principles are grasped. In Fig. 1 we have a curve (A-B) which shows the effect of the grid voltage on the plate current. As you may know, the heated filament in a tube throws off electrons which act as "'carriers" for the '"B" bat- tery current from the plate to the filament. The voltage impressed on the grid has a very decided effect on the amount of current that may flow over this carrier path of electrons, and our diagram shows a sample curve. Thus it will be seen that with the grid about 1 volt '"nega- tivé" the plate current will be about one-fourth of a milllampere; at "gero" grid voltage the plate current will be about halfway between .5 of a milllampere and 1.0 milliamp. Notice that the curve has a rather sharp bend at the bottom. The sharper this bend is the better de- tector the tube will be when op- erated ag a detector by the grid bias method. For detector action with grid bias | we operate the tube just where the | bend occurs, as shown. incoming oscillations, such as shown by the "incoming signal" will vary the grid voltage, and in doing so wll vary the plate current, But if the tube is operated on the bend, you can see, by projecting the signal oscillations up on the curve, "A-B", that a kind of lop-sided amplifica- tion takes place. The line designated "normal plate current" is the plate current that would maintain if the grid current represented by the vertical line "X" remained constant. But the incom- ing oscillations extending on each side of this line cause--due to the bend in the curve A-B -- the in- creases (I) in the plate current to be considerably greater than the de- crease (D) below the "norma!" line. This results in a resultant positive variation, shown by the dotted line, and this is heard in the phones. In other words, the plate current both increases and decreases in the headphones, but the increase is so much greater than the decrease that the general effect is that of an in- crease, and this will exert an in- creased pull on the headphone diaphram which can be heard as the signal. Soft tubes usually have sharper "bends" than hard tubes, which is one of the reasons why a 'soft tube often makes a better detector when operated by this "biag" method. In fact, some hard tubes have a curve which is almost a straight line, and has little. if any bend.: adi puipartronly | mapio BROADCASTING | The following is a list of radio stations and their broadcasting pro- grammes which may be heard local- iy on Friday: KDKA (920) Pittsburgh, Pa. 11.15 a.m.--Concert by Daug- herty"s orchestra. 2.15 p.m.--Baseball scores, iun- ings by inning. 5 pm.-- Baseball ecores. 5.30 p.m.--Organ recital. 6 p.m.--Baseball scores; ert dinner 6.30 p.m.-- "Let's hear some mcre from Uncle Wiggeley"--the chil- dren's period. 6.45 p.m.--News bulletins. 7 p.m.-- Baseball scores. 7.40 p.m.--*"Stockman"' report on primary livestock markets, includ- ing 'grain, feed, cotton, sugar, wool and produce. $ p.m.--Concent by the KDKA Ser- enaders, saxophone quartette and the Davis Male quartette. WGY (380) Schenectady, N.Y. 11.45 a.m.--Weather forecast. 1 p.m.--Mausic and household talk. 5.30 p.m.--Stories for children. 6 p.m.--International Sunday '| school lesson. Michigan youth dislocates his e men believed to be principals EA | heck in diving in Lake Erie and ET Ee i Brinoivals _ died shortly after at Simcoe. under arrest at Windsor. Sw , 7,15 p.m.--Baseball results, 7.30 p.m.--Comncert by the New York Philharmonic Orchestra. 10.30 p.m.--Musical programme by pupils and faculty of Round Lake, N.Y., Summer School of Music. WBZ (887) Springfield, Mass, 5 p.m.~--Dinner comoert by the W BZ Trio. 6 p.m.--Results of games played by the Eastern, American and Na- tional leagues. 6.05 p.m.--Market reporis as furnished by the United States de- partment of Agriculture at Boston. WJZ (455) New York City. 4.30 p.m.--Hotel Astor Organ re- cital direct. 7 p.m.--Ernie Golden's McAilpin roof orchestra. 7.20 p.m.--Fimancial develop- ments of the day. 7.30 p.m.--Emie Golden's McAl- pin roof orchestra. 8.30 p.m.--New York Philhar- monic orchestra. 10.30 p.m.~--Harold Stern's Belle- clair Towers occhestra. Complete radio programmes sold at Canada Radio Stores. The slayers of Mrs. Rosalie Evans have been arrested in Puebla state, Mexico. . | ones neccessary. | WHY THE WEATHER? | DR. CHARLES F. BROOKS Secretary, American Meteorologioal Society, Tells How, Gutters and Sewers for Downpours. In planning gutters and sewers for a town, the engineer must consider a number of points. He will study the rainfall records to determine the maximum fall which is likely to og- cur in periods of five or ten minutes, or an hour, and must also consider what per cent. of that will neces- sarily run off. Some cities in fairly arid regions may be afflicted with cloudbursts, and so may require larger gutters and sewers than cities where the average rainfall, though greater, is more evenly distributed. Thus Cheyenne, Wyoming, has gut- ters three feet deep. In towns of northeastern Porto Rico, where the rainfall is heavy, gutters are so deep that they have to be bridged for the entrance of every house, Besides rainfall, the steepness 'of slopes and imperviousness of sofls or surfaces are important factors in de- termining runoff, and hence the sewer requirements. W. E. Sullivan, of Cincinnati, has found that on a naked hillside area, the {mmediate run-off is usually 10 to 20 per cent. of the rainfall, the higher percent- ages prevailing where the hillside is quite steep with scanty soil cover- ing underlaid rock. In a suburban district 30 per cent. of the water may fail to sink into the soil, while in a compact residential district, with a house on every lot, the run-off is found to be 40 per cent, of the rain- fail. In factory areas as much as 80 per cent. of the rain must often be carried away by the sewers. In- deed, in a mercantile district of Cin- cinnati{ it was found from actual sewer gagings that the run-off was 85 per cent of the rainfall. The in- creasing percentage of run-off as cities become built up overtaxes early sewer systems and makes largen) Brockville Water Safe. : Brockville, Aug. 7.--Bacteriologi- cal report of the Brockville water supply, following an examination at the laboratories of the Provincial Board of Health at Toronto, fails to reveal the presence of any bacilli. The quaatity of chlorine deposited daily--fourteen pounds, was ocon- firmad by the board and instructions given to continue the deposit of such a quantity. Come With Rotary.~ To Gananoque Friday night. Str. Waubic moonlight excursion. Now any | I Soccer: All-Toronto 4, Corinthians 2; AR-Toronto 1, Montreal 0. | FRIDAY! | AT STEACY'S In conjunction with our August Sale of Home Furnish- ings we offer as an added feature for to-morrow morning-- Double Discount Stamps ! From 9to 1 O'clock Shop early to-morrow and take advantage of this sale event as well as participating in the following special at- tractions. Genuine Gold Seal ongoleum Art Rugs AT THE LOWEST PRICES EVER QUOTED! 50 of these handsome, guaranteed Floor Rugs so easy to clean and so fine in appearance. In a full range of sizes, pat- terns and colorings: Reg $450 Sale Price $3.48 Reg- 36.75 Sale Price $4.98 Reg. $9.00 Sale Price $6.95 Reg. $11.25 Sale Price $8.48 Reg. $13.50" Sale Price $9.98 Reg. $15.75 SalePrice $11.48 Reg. $18.00 SalePrice $12.98 Reg. $20.25 SalePrice $14.48 Reg. $22.50 Sale Price $16.98 Take advantage of these unprecedented low prices and se- cure your Fall requirements to- morrow. NEW FALL COATS You need one of these Fall Coats right now for imme- diate wear, and you will find them perfectly suitable well into the winter. Beautifully made of lovely soft fabrics with and without fur. They are certain to appeal to wo- men of discriminating taste. AT POPULAR PRICES THROUGHOUT ! Size 3x9 ft. Size 44x9 ft. Size 6x9 ft. Size 74x9 ft. Size 9x9 ft. Size 9x10} ft. Size 9x12 ft. Size 9x131 ft. Size 9x15 ft. STEACY'S - Limited 'Kingston's Shopping Centre"