AUTOMOBILE 



515 



AUTOMOBILE 



Cylinder Head 



Inlet Manifold Cam Shaft Sear Automatic 

 .Electr.c Generator \Sprockets Spark Advance 



LONGITUDINAL SECTION THROUGH MOTOR AND TRANSMISSION 



hours twenty-four minutes forty-two seconds, 



an average of 102.60 miles per hour. This is 



faster than any railroad train has ever trav- 



for the same length of time. The fastest 



ever made by a railroad train was in 



la in 1901 at the rate of 120 miles an 



hour for five miles, but the highest average 



for a distance of more than ten miles is only 



98.7 miles an hour, and for 100 miles the record 



is an average of only 84.6 miles per hour. The 



Inchest speed ever maintained by an aeroplane 



is 126.69 miles an hour. 



3. Trucks and other Commercial Vehicles. 

 class includes all styles from the small 

 cry wagons of the retail stores to great 

 trucks for carrying coal, stone and other heavy 

 materials. The special features of these 

 hides arc their greater capacity, as compared 

 with horse-drawn wagons, and tin- greater dis- 

 tance they can cover. The earliest care were 

 bodies of horse-drawn wagons placed on a 

 motor chassis, but now special designs are in 

 use for every possible purpose. Automobiles 

 i>eing us-I for business purposes to an 



nt ; tin- itnti.,1 IM\ Mfe 



is somewhat greater than the cost of a horse 



iii-I wagon, but tl iterance charge is 



less, and the amount of work done is t. 



tor. A team and wagon can cover an 



rage distance of sixteen to twenty miles a 



day; a small delivery automobile cm rover 



this distance in an hour, and even a heavy 



truck can cover seventy to 100 miles a day. 

 Under the same conditions the cost of deliver- 

 ing a package by automobile is less than one- 

 half the cost of delivery by horse and wagon. 

 In the large cities the automobile is rapidly 

 supplanting the horse for all business purposes. 



The Mechanism of an Automobile. The pro- 

 pelling power of an automobile is derived 

 either from steam, gasoline or electricity. 

 Other methods have been tried, but these three 

 are the only ones which have ever been in 

 practical use. 



Steam-Driven Vehicles. This was the first 

 type of automobile to be developed. In this 

 type the fuel, usually gasoline, is burned under 

 a water-filled boiler. The steam generated 

 then drives a steam engine almost exactly tin 

 same as that of a railway locomotive. At 

 first the "steamers," as they were called, v 

 the most popular variety. They ran quietly, 

 because they had no noisy gears or transmis- 

 sion; tin ir SJM..I could be varied merely by 

 shiftmc ; throttle; :m<l there was always a 

 reserve of po\v r in the boiler which made it 

 easy to start the machine. As the gasoline 

 automobiles, however, were gradually im- 

 proved, the disadvantage of the steamers began 

 to weigh against them, and in a few years 

 th'-ir popularity was largely gone. In 1916 

 only one important steam car was manufac- 

 tured. The hi, f objections to them were the 

 dam from the flame, the firebox being 



