A horse can accomplish about 70 times more work than a person. The horse served this family as the equivalent of an automobile, a truck, and a farm tractor.
The vast wealth we enjoy is a direct result of our capability to consume energy. We consume, primarily, carbon energy. Carbon energy utilization multiplies our energy consumption enormously. It is not unusual to travel 500 miles a day in an automobile. If a person were to walk 500 miles, covering 30 miles per day, it would take 16.7 days. If we account for the energy requirement to make the trip in an automobile, we have to account for the movement of about 3500 pounds of automobile. If you could walk 30 miles a day while carrying 100 pounds, it would take 35 trips and about 584 days to do what requires only about ten hours in an automobile! Our energy consumption in the United States is about 10,000 times greater than it would be if we had to rely only on human energy. The youngest person in the family photograph at the top of this page had been no more than fifteen miles from home by age eighteen, but a few decades later traveled to six continents on commercial jet airliners. How much human energy would it take to get a 100 ton airliner off the ground?
