| . terious at all. WINNETKA WEEKLY TALK, SATURDAY, DECEMBER 6, 1924 17 DIRT CAUSES MOST TROUBLE Expert Tells How Engine Parts Are Tested Crystallization and breakage, form- erly given as the cause for the failure of a part of a motor car after a long period of service, has become one of the exploded theories of the past. Studies which have destroyed the old "crystallization" theory have also pointed the way to even greater de- pendability in highly stressed parts of the present day car, according to IL. A. Danse, metallurgist of the Cadillac Motor Car company. Mr. Danse explains that in advanced engineering circles the mysterious something commonly called crystall- ization and breakage has been ana- lyzed just as medical men analyze a disease and isolate its germs and that it is in reality "fatigue" breakage, due to impurity in the metal or some one other definite defect which can now be exposed by known laboratory and physical tests. "As metals are naturally crystalline in structure," states Mr. Danse, "it is evident that breakage in service is not due to crystallization. The metal is a crystalline mass from the time it is first melted and poured. When it solidifies after melting and pouring, it assumes the crystalline character; the same as water solidifies to snow, frost or ice crystals. Just Plain Dirt "Researches in metallurgy show that where a motor car part fails in ser- vice, the principal cause is not mys- It is usually just plain dirt. It is impurity so microscopically fine that without the most conscien- tious examination it defies detection. "The method of determining the cleanliness of a metal is really very simple. It is merely a process of tak- ing infinite pains--accuracy of ex- amination and analysis to a degree formerly unknown even in the best of laboratories. "Here at Cadillac every lot of metal intended for use in highly stressed parts for the car must undergo the most thorough microscopical examin- ation. "The sample to be examined is first polished to a degree of smoothness seldom seen in commercial products. Smoothness in highly polished plate glass or in a piece of silverware is crude compared to the smoothness re- quired in the testing laboratory. Spoon Illustration "Take a silver spoon, for example. If you are invited out to dinner to. night and have been lucky in your mvitation, maybe there will be a real silver spoon at your place, newly polished by the best Good Housekeep- ing methods. To your eye it looks perfectly smooth. As it passes your lips they also record perfect smooth- ness. That surface under a powerful miscroscope would have ruts and fur- rows; and a plated spoon in a quick lunch room, under this same micro- scope, would plainly show mountains and valleys. "When we prepare this sample for examination, we must make it even microscopically smooth. Five hours is spent in polishing a half-inch square of surface. "This surface is then examined un- der a glass magnifying to 100 dia- meters--a task for a busy 20 minutes. One might examine it in 15 minutes. but he would have to slight some areas of the surface which might contain dirt inclusions." The metallurgist was interrupted by an exclamation, and continued with a smile, "Yes, you can glance at a nickel in an instant and know that it is a five-cent piece, but if you really want to see it and know how pure ( ADLITY to as- sume responsi- bility in such a man- ner as to relieve the family of all worri- ment has been the secret of our success. High standards gov- ern our work. We Understand & hoo Evanston that nickel is, it will take vou 20 minutes to explore its whole surface-- and at that will need to hustle. "After a thorough visual micro- scopic examination the metal is photo- graphed with a camera which mag- nifies from 109 to 2700 diameters and suspected areas are more closely studied. Watch for Impurities "The structure must be fine in order to have the strength which the work to be done by the part requires; so we must watch for impurities which would lessen that strength. "Sometimes we have to follow a piece of metal all the way back to the steel mill, where it was first poured © into ingots, and suggest changes in methods there in order to bring it up to the required standard. "This original inspection is just a beginning. That lot of metal is fol- lowed all through the manufacturing process. At every stage samples are brought to the laboratory and re-ex- amined. Every day connecting rods, for instance, are taken from stock, cut open and examined just as a check upon the cleanliness and strength of .e metal being used. "A single defective part in a steer- ing mechanism, we remember, might ¢ some future time cost a human fe, and every possibility of such a part entering a Cadillac car must be absolutely eliminated before that part is assembled in the finished chassis." IF YOU USE BALLOONS JUST GLANCE AT THIS The motorist who changes his tires over to balloons or any other low pressure tire should equip with the iew Gabriel balioon-type Snubbers to 'onferm. points out Arch B. Van Yeusen of Motors Service, Inc., local Gabriel distributor. "Car owners changing over to low pressure tires should come in to see us regarding the proper snubber if they desire actually to achieve the easier riding results they seek," he said yesterday. "The new Gabriel 702 Church Street Phone University 1848 STH A Fine Line of Lorgnettes, Oxford Eye Glasses, Field Glasses, Barometers Thermometers, Magnifiers, Etc. for Xmas HATTSTROM & SANDERS Scientific & Manufacturing Opticians EVANSTON Opposite Orrington Hotel Open Thurs. & Sat. Eve. till 8 P. M. balloon-type Snubbers are designed to give the necessary free play that en- ables low pressure tires to absorb the small bumps on apparently roads. At the same time, they have the increased braking action needed to control the springs and tire action when larger bumps are encountered. "These new Gabriel Snubbers make a world of difference in the riding comfort of cars equipped with low pressure tires. They are especially de- signed for balloon tires, just as the standard Gabriel Snubber is designed for standard tires." smooth | In June, electric light is used in the average residence only ohe hour and a half a day, while in December it is used about six hours and fifty minutes. per day. ; DR. SOFIA HAAG Naprapath Chronic and Nervous Ailments A Specialty Hours 2 to 5 and by appointment Office: 897 Cherry Street Phone Winnetka 804 At all First class Grocers po, " Ce \Q 3 \! wt " Ny gredients. 7 pert bakers. . ' a Sa SIO CHICAGO AVENUE Evanston, I11. or 7 K RS Tasty and delicious! A 4 "% everyone says who samples SEIDEL'S 'Macaroons and Lady Fingers! <7) They're made of the choicest in- And they're made by ex- Say "SEIDEL'S" to your Grocer | SEIp That's what Cer The Home of | Good Baking Ep PHONE EVANSTON 1200 FAMOUS FOR MACAROONS & LADY FINGERS HAMILTON © CARROLL RIDGWAY INC. The Store for Children At this joyous season when parties and the chil- dren's happiness are uppermost in mind, what could be more bewitching than one of our dainty party frocks? Evanston -- TWO SHOPS -- Wilmette sy