Few inventions have had as profound an impact on modern life as the automobile. The word has become synonymous with mobility and independence, but also with environmental degradation and societal fragmentation. Thousands of individual parts make up the contemporary automobile, which is one of the most sophisticated and complex pieces of engineering ever developed. The automobile’s design is a careful balance of many factors: speed, safety, comfort, appearance, economy, and pollution control. While a car can be customized with different features, the basic systems remain the same.
In the early 1900s, automobiles came to dominate the streets and highways of most countries, with a few exceptions. The era of the automobile was the culmination of several technical developments that occurred toward the end of the nineteenth century. Gottlieb Daimler, Karl Benz, and Nicolaus Otto are generally recognized as the inventors of the first modern motorcar. Among the many innovations that they introduced, their four-stroke engines fueled by gasoline and their standardized parts made them competitive with horseless carriages.
The most fundamental feature of an automobile is the chassis, or frame, which supports and protects the various other parts. The frame must be strong enough to support the weight of the automobile, but flexible in order to absorb the shocks and tension produced by turning and road conditions. In addition, the frame must allow the engine to be positioned at the front of the automobile for easy access and to provide a powerful driving force.
Another essential component is the internal-combustion engine, which generates power to drive the wheels. Depending on the size of the automobile, the engine may have from four to eight cylinders. The cylinders are arranged in a sequence, allowing each to fire on its own in turns as the crankshaft is turned. Each cylinder produces the combustion that drives the pistons, producing the mechanical energy to move the car.
A vehicle must have an efficient system to lubricate the moving parts, cool the engine, and remove the exhaust gases. These systems are modeled after the human circulatory system, with the radiator, water pump, and oil pumps performing analogous functions. The automobile’s engine also requires a supply of fuel, which is delivered by the carburetor or direct injection system.
Finally, the automobile must have a way to be stopped and started easily. Stopping mechanisms include the brakes, which apply the frictional force to the wheel, and the transmission system, which turns the rotation of the wheels into the motion necessary for forward travel.
The United States offered a unique environment for the automobile industry to flourish. With its large land area and a great diversity of people, the nation had a huge demand for transportation vehicles. Moreover, cheap raw materials and a long tradition of industrial manufacturing enabled cars to be produced at lower prices than in Europe. This market, combined with the innovation of Henry Ford in mass production techniques, helped to bring the automobile within the means of most middle-class families.