Technique : revue industrielle = industrial review, 1 septembre 1930, Septembre

[" ey 4 14 IBN Ti DIJK IN AU NII Jl NINN NNN Ji A A OU INI NUE = En Hi >, gh ( NII A a J 2 (& 0 A } J 2 Æ 3 NIE A C A J A Gt » = * ; a ç 1H , =X TECHNIQUE S L2 Né & D REVUE INDUSTRIELLE | > INDUSTRIAL : q 2 4 REVIEW =~ D LL > © .i A S (J à A < NH a ) J A G RZ = d : = = à = SEPTEMBRE - SEPTEMBER |) = = = D 7 = MCMXXX D = 2 = G D 21 Di Ni NNN NTN NY i IIIT NTN NIN X i INIT X JOY PROVINCE DE QUEBEC, SECRETARIAT DE LA PROVINCE Ecole des Beaux Arts de Montréal 628, rue Saint-Urbain, près Sherbrooke (ouest) Directeur: CHARLES MAILLARD ÉTUDE D\u2019UN ÉLÈVE DU COURS D'ART DÉCORATIF ENSEIGNEMENT GRATUIT L'école est ouverte aux jeunes gens et aux jeunes filles, avec ateliers séparés sauf pour les cours oraux, ainsi que pour les cours d'architecture et de composition décorative, où cependant les sections sont divisées.Ww No L\u2019Enseignement comprend: ARCHITECTURE, PEINTURE, SCULPTURE, ART DECORATIF .Architecture:\u2014Formation d'architectes diplômés (5 ans d'études) de dessinateurs pour entrepreneurs industriels, etc.Architecture pratique (cours du soir).Dessin et Peinture d\u2019Art, Aquarelle.Statuaire.Art Décoratif dans toutes ses applications (théorie et réalisations.) a) Adaptation architecturale, comprenant une section de sculpture ornementale et une section de peinture décorative.; b) Adaptation aux métiers; étude des différentes techniques\u2014bois, métaux, céramique, verre, etc.Cours Oraux et Spéciaux:\u2014Sciences appliquées à l'architecture; perspective; anatomie artistique; histoire de l\u2019art.Formation de professeurs de Dessin à Vue, diplômés après 4 ans d\u2019études.LES COURS ONT LIEU DU 1\u201c OCTOBRE A FIN MAI L'inscriphon des élèves commence le 15 septembre STERN FERN NIN - gags == \\ Lr ELECTRICITY | Montreal Technical School 200 SHERBROOKE STREET WEST Founded by the Goverment of the Province of Quebec Subsidized by the Provincial Government and the City of Montreal Prepares young men for positions in industrial life as experts, foremen, etc.DAY CLASSES 1.\u2014Regular three year Technical Course for boys and young men who have completed at least | one year in a regular high school or its equivalent.2.\u2014Trades\u2019 School Course for boys and young men who have not the necessary preparation to follow Course No.1.| 3-\u2014Printing Course for young men who have completed one year of a regular high school course and who are at least 16 years of age.| 4\u2014Automobile Short Term Course (9 weeks) for young men who wish to learn the care and repair of the automobile.Applicants must be at least 18 years of age.EVENING CLASSES | 5.\u2014All Trades and Technical Subjects.Ask for a Prospectus For further information, apply to Montreal Technical School Note: Regarding Courses 1 and 2 for worthy cases, pupils whose family conditions warrant the same, may receive a remission in part or in full of the fees required for these courses.l= Encouragez nos annonceurs Sm ee SHAWINIGAN TECHNICAL INSTITUTE FOUNDED 1912 By Mr.J.E.ALDRED, President of Shawinigan Water & Power Co.Under the guidance of a Committee of Management composed of the Managers of the Local Industrial Corporations.Subsidized by the Local Industries, Provincial Government and the City of Shawinigan Falls.of Senior Matriculation.ro course Number 1.Industrial English and French.DAY CLASSES 1.Regular four-year Technical Course, the final year the equivalent Trade Courses for students without sufficient preparation to follow 3.Special courses in Automobile Mechanics.NIGHT CLASSES Course in Machine Shop Practice, Carpentry, Oxy-acetylene Welding, Chemistry, Automobile Mechanics, Electricity, Drafting, Mathematics, For further information apply to SHAWINIGAN TECHNICAL INSTITUTE MORE PEOPLE MEANS.MORE FORESTS An increasing population means an increasing need for wood.Although our population may increase, the amount of land in this country does not.The only way out of the problem of supplying a continually increasing demand for wood\u2014a demand that is being made upon a continually decreasing forest\u2014is to put every acre of available land to work growing trees.After Marjorie and Mary had gone to bed, a piercing wail, followed by sobs, came from their room.Their mother hurried up.Marjorie (crying): \u2018\u201cMary hit me on the nose.\u201d Mother: \u201cMary, why did you hit Marjorie on the nose?\u201d Mary: \u201cWell, mother, you don\u2019t think I'm going to get up and turn on the light just to see where to hit her.\u201d HARDWOOD FROM SOFTWOOD The time is coming when wood as hard as eb may be produced, by special treatment, from quick-growing, soft textured woods, say scientls who are investigating this particular question.De THE WORM AT THE CORE When you find a worm in your apple, don\u2019t blà the merchant who sold you the fruit \u2014blame person who destroyed the bird that would have eat the worm.Those who do not protect the birds je greatly to blame for wormy fruit and vegetable{, Sop PROLIFIC PARENTS | The average pine or spruce tree produces f 50,000 to 100,000 seeds, which are carried far wide by the wind, often to a distance of as m as a mile from the parent tree.1 Patronize our advertisers HARRISON & CO.Dominion fquare | HEADQUARTERS FOR SCIENTIFIC INSTRUMENTS (hronomeiers Vient de paraître Dictionnaire Larousse Complet Edition Canadienne (303° Edition) avec 2 Nouveau supplément ue : canadien Nouvelle édition revue t z : corrigée et considera- | | 0 Js ARE JRE CIS LI CPS CN OF mw ! blement augmentée.5 .Le seul dictionnaire | Dictionnaire URE = français , ~ +, \\ Ly NN [vd & LARS 2.0 > Nz q = \\ 4, S \\ 2 = ° \u20ac 7 SN, Po.NN > > 2 L 1.0 2 N22 Po Ve Fe oP, Ne < Le VS La, ss NL ~ NE ~ = So 0 ~ 1 1\u201d 1\u201d 3\" 8 4 2 4 FrG.3.\u2014Thickness of Section Acoustical Characteristics of Movie Screens\u201d By H.F.Hopkins Transmission Instruments Research system was used chiefly to provide a synchronized musical accompaniment for the picture.The loud speakers, as a result, were frequently placed in the orchestra pit to give the effect of the presence of an actual orchestra.With improvement in technique, however, the reproduction I: its pioneer stages the sound-picture *Printed through the courtesy of the Bell Laboratories Record [ 28 | TECHNIQUE TABLE Î Septemb «+ > Comparison of the Effect of Silicon and \\a Nickel on Combined Carbon Content! of a 14\" Cast Arbitration Bar.| In a 3.609, carbon iron Increase of nickel Silicon 1.40% 1.40% 1.40% 1.40%, 2.03%, 2.56: Niel 550 1.2377 067° 000° 000° 0.00 Combined Carbon 0.56 0.62 0.76 0.72 0.59 In a 3.15% carbon iron Increase of nickel Increase of silice : 0.45 Silicon 1.25% 1.259% 1.25% 2.00 Nickel 4.00 1.00 0.00 0.on] Combined Carbon 0.74 0.80 0.83 0.46 | PERCENTAGES OF SILICON AND NICKE REQUIRED TO RENDER CASTINGS OF : DIFFERENT SECTION COMPLETELY (GRAY AND MACHINABLE With Carbon 3.40-3.60% With Carbon 3.10-3.30% | Ÿ Silicon | Thickness of Section\u2014Fig.3 A Nic, TT N= #- \"1% Pick Frs NE a a ; i = SZ 1 2\" 3 of dialog became more general; the accom paniment feature decreased in importanct until now a sound-picture is usually under stood to mean a talking picture\u2014a dramati screen entertainment reproducing the voicé as well as the scene.To produce the prope effect under these new conditions, @ different location for the loud speaker was necessary since the sound should (Continued on page 33) Increase of silicon 4.4 d {+ ti | 4 il i | Se TECHNIQUE September ig ' ° ° us Discovering the Saguenay in ig By AGNES ESTHER MCLEIsH Sy, frit F you desire to feast your eyes on the treat; not only to Canadians, who can never n° solemn beauties of nature, where ui J rugged mountains and rushing waters \u201cm Bind their being; where the wild creatures id of the forest wander unmolested through i\" ;§ their leafy domain; you have only to board } a Saguenay-bound vessel from the harbour of of Montreal and before you lies a voyage Wy that for grandeur of scenery and wealth \u201cHof historical associations, 1s unsurpassed throughout the broad and fertile Dominion of Canada.learn too much about their country, but to those who may not realize or suspect what the real Canada is like.The boat slips anchor at sunset.Travellers, embark! Before you lies a long and delightful journey filled with many wonderful and intriguing sights.The harbour is bathed in a flood of living gold which transforms the wate: for miles around into a molten likeness of that same precious metal.Purple clouds The St.Lawrence Coast.\u2014J Those who are familiar with the mighty St.Lawrence can easily visualize the broad expanse of green country and sloping hills against a background of higher mountains in the distance, which border its curving es shoreline.To them, it is, perhaps, the height of enjoyment to sit on the deck of a swiftly-moving steamer, watch the shore slip gently by, follow the sea-gulls as they swoop and soar between river and «of Sky, and note the sun as it kisses the wf sparkling waters until they break forth if nto golden smiles.ar This voyage by boat is famous through- ; .der\u201d out the world, and once experienced, it is - never to be forgotten.It is a great pity \u201cÀ that more people do not grasp this oppor- A tunity of a glorious adventure into the very heart of nature.Besides the lure of beauty, this excursion also presents an educational float high in the heavens like royal banners waving farewell.The island of Montreal soon vanishes in a shining mist and the epochal voyage has begun.Twilight's dusky gloom pursues the craft as she glides onward over the rosy surface.The moon rises and casts her silver beams over the darkling waters.The stars emeige, one by one, fiom the velvet cloak of night and nod gaily to their reflections which smile back at them across the great gulf of space.Three Rivers is reached in the wee sma\u2019 hours of the morning.The boat docks at the quay for the space of an hour or so.It is performed with a smothered commotion and low hum of voices so that the sleeping passengers may slumber undisturbed.Dawn the following morning finds the ; fi E on Septembre TECHNIQUE boat anchored in the vicinity of Cape Diamond, above which rise the stately ramparts of Quebec\u2014that justly called Gibraltar of America.The gray-walled citadel crowns the highest point, while to the left, as your face the river, Chateau Frontenac with old-time hospitality flings wide her portals.But we cannot linger to admire, lest like Ulysses of old, we yield to the siren call of old Quebec and remain beyond the appointed time.Septembe ~~ with tall, swaying trees and flower-clustere pepe fields that seek the water\u2019s edge\u2014a ver: ph table woodland paradise surrounded by a azure sea that, murmuring, gently laps it x} , A sun-kissed shore.It would not take a grea 100 deal of imagination to picture it people! gh with myriads of tiny fairy-folk playing ir never-ending game of hide-and-seek amon: 3x: the whispering flowers.The scene assumes a different aspec «7 as lofty mountains begin to rise boldl After leaving Chicoutimi.A rapid transfer of boats is made and we resume our journey in the special Saguenay steamer.Quebec fades in the distance, while before our eyes spreads the broad, green bosom of the Island of Orleans.It lies like a huge emerald leaf on the surface of the St.Lawrence, so thickly is it covered along the shore.The river broadens nod - ticeably as mile after mile is swallowed by the gray distance.Murray Bay with its glistening white stone Manoir Richelieu is the next place of interest to greet the traveller's eye.Framed by purple-misted mountains, its magnificent grounds and Trinity on a Foggy Day.[30] 1 fs 4 oo y Septembre TECHNIQUE September | Ui splendid golf course create a summer resort broken shoreline.The lights of Tadoussac \u201ciy -hat is known the length and breadth of fade in the darkness as the vessel noses her Ë fe \u2018he continent.Beautiful homes emboss the way over the daik expanse of that mys- E Fly ill sides, like lesser stones in the cluster terious river.E tanb of a ring.| The passage up the Saguenay is a swift \"md Time moves on and, in the light of the and silent one for it is made in the deep of ; Day setting sun, Tadoussac is beheld in all the night.Little can be seen of either shore, E thy race of her cool northern charm.Her except darker shadow against a somber sandy beach gleams like mother-of-pearl sky, which indicates the presence of rocky ug n the fading light of day.Surely the spirit cliffs.Occasionally, the night blackness is tj of the ancient Indian broods over this pierced by the warm glow of a beacon seauteous land, smoking his pipe of peace, light, which forms the sole guide of the \u2018he while he gazes with sad eye over his pilot in steering his course through the ost domain.treacherous channel.H + 1 Hi H À fi MN) ! A A } I i! Triple-Towered Trinity.At this point the boat leaves the mighty Chicoutimi is reached in the early morn- st.Lawrence and turns her prow up the ing.It proves to be a busy little city with dl urbulant Saguenay, which leaps like a many fine streets and nobly constructed I vild animal, unleashed, from behind the buildings.It is a surprise to those who I Giant Eternity.[31] H Ri Ri B15 tS Septembre TECHNIQUE Septembi « expect to find northern Quebec a country of rustic villages and old-fashioned trading- posts, still menaced by the danger of lurking Indian braves.The return voyage along the Saguenay is viewed with great expectation by all on board, for the combined beauties of Capes Trinity and Eternity lie in store for them.On both sides, rise steep cliffs, that for the most part, are innocent of vegetation.They jut out sharply into the water, creating a wild and irregular shoreline.The clouds hang low and lazy, trailing white ones wreath the highest peaks, softening their rough contours, and almost hiding them from view.They appear remote and unreal like angry gods veiling themselves with clouds to hide their scars from the gaze of mortals.Here, the river down into rocky hills and jagged cliff The great river itself was once a might chasm through which white-frothed wate: : a 0 jus 00 roared, cutting deeper and deeper into th di stony heart of the mountains, until |!\" blossomed forth into the broad and flowir + stream which finds its source at Lake S ; John.The Saguenay has not the seren + quiet loveliness of the mighty St.Lawrenciia but rather a stern, majestic grandeur of i 1 own which reaches a climax in the twj.Capes of Trinity and Eternity.| A pen wielded by the human hand ca never do justice to the solemn dignity «1 the scene we are now approaching.The 1ai are crowded with impatient people, sa 4 with cameras.Their curiosity changes int something resembling awe as they drin:! in the wonder of what lies before them.Capes Trinity and Eternity as seen through the Fog.is extremely deep and is a dull slate in color, except where an errant white-capped wave is tossed up by the wind.This is no simple, pastoral beauty of land, nor yet the glorious panorama of color that riots through mountain and valley, but rather a stately, melancholy splendor that stiikes a minor note in the world\u2019s symphony of color.Grey is the keynote in rocky coast and river, but through this runs a melody of green and bronze which is found in some lonely tree or moss-covered stone.In spite of the lack of warmer hues, the scene does not give the impression of bleakness but rather of a solitude and greatness of things that endure forever; for here we are in the very heart of the oldest mountain chain on the American continent, towering peaks that, by the hand of time, have been worn [32] Two, gigantic masses of rock rise sheq i from the mirror-like calmness of the tin bay.Up and up travels the gaze before on can discern the summit and then it seem so infinitely far from where one stands, | mere atom on the deck of a toy ship.Hew from solid rock, Trinity and Eternity ar masterpieces of nature\u2019s sculpturing ; sleer ing giants in whose bosoms thunders th heart of the world; an eternal pledge of th Creator's infinite power, and enduring lik faith throughout the countless years gon by and those to come.They seem to pierc the sky, almost rending the veil that bar us from the unknown\u2014yet not quite.Cap Eternity is an immense pile of stone whic faces Cape Trinity.As the name suggests Trinity is split in twain near its crest and 4; when seen from the Bay, resembles Tv si FSU A fy iat f i th Ii RA Lin Clg dp i ane \u2018au save rh il de ring \u201chi gf gr bé | Septembre disturbance within the earth\u2019s TECHNIQUE September .mediaeval, triple-turreted castle.Perhaps, thousands of years ago, some great internal interior caused these great cracks to open massive ellers may disperse to their various homes.But we know they carry in their hearts the memory of a wonderful experience.They have only to close their Trinity sides, leaving scars that will take eons of time to obliterate.High on the first summit, stands the statue of \u2018Our Lady of the Saguenay,\u201d placed there by the faithful hands of an old French trapper, some fifty years ago.Alone, she watches over this grim land, a proper guardian for its frowning solitude\u2014a white emblem of peace in a scene desolate and wild.Eternity raises its head to the skies, communing with beings unseen by human eyes.A shapeless mass of rock, yet Eternity is invested with a silent majesty which is enhanced by the glory of Trinity.A single shriek of the ship\u2019s siren is sufficient to set the echoes ringing wildly.They bound from height to height with a wail that dies away into a long drawn cadence of sound.It brings to mind the stirring lines of Tennyson's \u2018\u2018Bugle Song,\u201d in which he immortalizes the echoes in the lakes of Killarney.After skirting the little bay, we bid a last farewell to Cape Trinity and Eternity and continue our voyage back along the Saguenay.The coast which the darkness of the night had hidden is now visible to the eye.The shore is very picturesque and becomes heavily wooded as the mouth of the Saguenay is reached.The passage up the St.Lawrence is made at night, and another dawn discovers the steamer anchored at the foot of Quebec.The great voyage is over and the trav- Cape Trinity as seen from the deck of the \u201cSaguenay\u201d [33] eyes and before them will pass the various scenes they have witnessed, which culminate in the silent glory of Cape Trinity and Eternity.Acoustical Characteristics of Movie Screens (Continued from page 28) appear to come from the speakers\u2019 mouths and thus from the screen itself.Behind the screen seemed the most suitable place.This change brought an added difficulty into the reproduction, however, due to the partial obstruction of the sound by the screen.To determine how serious the obstruction was required acoustical tests which the laboratories was well equipped to make.The frequency response of loud speakers has been the subject of many studies.To make similar tests with a screen in front of the loud speaker, and to compare the resultant sound received to that without the screen in place was, therefore, a comparatively simple matter.This has been done to a large extent as a matter of routine in determining whether certain screens will be satisfactory for sound-picture reproductions.A screen may be expected to transmit sound in three ways.It may vibrate as a diaphragm driven by the sound from the horn and in turn produce new waves which Septembre TECHNIQUE i } ! Aggregate area of openings 449 of total screen area.DO OO § Aggregate area of openings 5% ot total screen area.Area of individual openings .0018 sq.in.Screen thickness .013 in.Aggregate area openings 59 oO p - 7 of total screen area.Area of individual openings .0013 sq.in.1 oO Screen thickness .030 in.EFFECT ON TRANSMISSION IN DB.5 Aggregate area of openings 4% of total screen area.Area of individual openings .0013 7 » > vy sq.in.< \u20ac 2 = hr Screen thickness .030 in.FREQUENCY F1c.1\u2014Transmission characteristics of modern movie screens with punched openings compared to the earlier solid type.will be heard by the observers.Also the original sound may be transmitted through air passages in the screen itself, which is a second method.The third is by wave propagation with the screen material as the conducting medium.Because of the physical properties of the screen, however, the power transmitted by this last method is much smaller than for the other two so that for practical purposes it may be neglected.[34] [FRAT Type of screen used before advent of sound pictures.2 From a knowledge of the tension to which a screen may be stretched and of the density of the material, it might be expected that the natural frequency of the screen as a whole would be low.At this natural frequency the screen would transmit efficiently but for higher frequencies, where the mass reaction becomes large, the greater portion of the driving force would be consumed in accelerating the screen Septembeié A XL = v= VL SN À \\ 0 À 1 St TECHNIQUE September have very satisfactory transmission characteristics.Hing.Before the advent of sound- a+ c Pictures the screens were heavy and not porous.Sound could be transmitted only by diaphragm action.The result 1 6 1s shown at \u201cA\u201d of Fig.1.There.is a rapidly increasing Hin loss with increasing frequency, and the irregularities men- ig tioned above are plainly evi- TNA dent.Since a loss of three db means that only about half of the power is transmitted the seriousness of the loss indi- s _ EFFECT ON TRANSMISSION IN DB Qo = % cated is obvious.5 ig § |} Curve \u201cE\u201d\u2019 shows the other extreme where the major part Cag of the energy is transmitted A through openings in the screen.For this screen the openings N constituted about 44% of the screen area, and it will be FREQUENCY and little would remain for moving the air load.This natural frequency, however, is ordinarily below the frequency band used in sound-pictures.The transmission\u201d efficiency of speech vibrations, therefore, would be highest at the lower frequencies and would decrease as the frequency increases.Furthermore over the range of frequencies involved, the screen is far from a simple vibrating system.Irregularities occur, therefore, in the sound transmitted although they may be small compared to the total effect.Transmission through air passages in the material proves to be much more satisfactory.Two factors are of primary importance.The aggregate area of the openings in the screen must be adequate to give the proper air load for sound radiation into the theater, and the dimension of the holes, principally the ratio of diameter to Iii the thickness of the fabric should be suffi- J ciently large to reduce the mass reaction to a satisfactory value.The effect of too R high a mass reaction is to produce an attenuation that increases with frequency; gwhile an improper air load produces a J general decrease in the efficiency of trans- ÿ mission.If these factors are considered fin the design, screens may be made which fe Fic.2\u2014Transmission characteristics of screers which allow the mesh opening of the weave to transmit the sound.[35] 8 observed that there is prac- ~ tically no attenuation of the sound, and that the irregularities, except at the very low frequencies where the data are perhaps less reliable, have been considerably reduced.Although such a screen is entirely satisfactory for the transmission of sound it is lacking in the desirable optical characteristics.Light 1s not reflected from the openings so that the total light reflected is reduced in direct proportion to the total area of the aperture.The tendency therefore is to provide smaller and more widely spaced openings, as a result of which sound transmission may be partly due to diaphragm action.Curve \u2018\u201cB\u2019\u2019 shows a characteristic screen of this type.The screen is like that of \u201cA\u201d but punched in it are holes 1.040\" in diameter which comprise about 49, of the total area.The screen thickness is .030 inches.The drooping of the curve at the high frequencies due to mass re- actance, is plainly evident although not nearly so pronounced as in \u2018A\u2019.There is also a noticeable loss over the entire range compared with \u201cEF\u201d.Curve \u2018\u201cC\u2019\u201d\u2019 shows the effect of increasing the open area by 25%\u2014using holes of the same size but with less separation.Although the dropping off at higher frequen- cles is still evident, the loss over the entire band is appreciably decreased.By maintaining the same percentage Septembre of open area but reducing the thickness of the screen to about half the former value, and thereby increasing the ratio of diameter to thickness of holes, a further evident gain is made.There is now little or no loss over most of the band and only a very slight falling off at frequencies above 3,000 cycles.The irregularities are also greatly reduced.The acoustical characteristics of such a screen would be considered very satisfactory, and the small percent of open space\u2014about 59% \u2014would not materially reduce the reflection of light.Openings in the screens discussed so far have been punched in a non-porous screen material, but many of the screens now in use are coarsely woven and meshes of the weave form the only openings for air conduction.As a result the openings are small and irregular in shape, and are apt to be partially filled by fibres from the surrounding threads.Because of this the sound transmission may be seriously affected.Graduates\u2019 Page Tu ENGLISH GRADUATE SOCIETY Montreal Technical School OFFICERS 1930-31 Hon.President IAN McLEISH, B.Sc.President W.H.JARAND, AM.E.I.C.Second Vice President: WM.BRADNER, First Vice President: C.H.DAVIS Assoc, I.E.E.Secretary: Treasurer: FRANK YATES, \u201924 T.L.DODS 2437 Orleans Ave., 2420 Pie IX Blvd,, Montreal.Montreal.ACTIVITIES A programme of the year\u2019s activities is outlined below and, while every effort will be made to work to schedule it may be necessary to vary this arrangement slightly.Individual notices will be mailed to each member covering these activities in detail.A summary of the Society's activities since its inception is also given which is both interesting and enlightening.It is the sincere wish of the council that with the aid and co-operation of all the graduates the coming year will show the steady progress as made in the past.SCHEDULE 1930-1931 Mon.Sept.29th, General Meeting.Mon.Oct.6th, 1st Lecture.Fri.Oct.24th, Smoker.[36] TECHNIQUE | tt S eptemp