Chemical challenges to fuel and refrigeration

Thomas Midgley was a chemist who discovered leaded gasoline and Freon - both of which have had profound effects on our lives today. Drawing courtesy of University of Pennsylvania Library.

Back in the Wright brothers' hometown of Dayton, Ohio, Charles Kettering and Thomas Midgley, of Dayton Engineering Laboratory Company (Delco), were tackling the army's fuel problem. At the time, all fuels used in airplane engines knocked violently when the airplane flew. Midgley and Kettering tried and discarded several anti-knock compounds: benzene froze too quickly, olefins turned to gum over time, ethyl alcohol ate up too much of the fuel. Frustrated by years of unsuccessful experiments, Midgley went all the way back to the periodic table, and began a systematic search of chemicals and chemical combinations. By 1926, he had combined ethyl alcohol with gasoline to produce ethyl gasoline, now known as leaded gasoline - an effective anti-knock compound, and a revolutionary fuel for aircraft and automobiles alike.

Thrilled with his success, Midgley marched straight back to the periodic table to tackle another problem that had been bothering him. In the early 1900s, mechanized refrigeration was emerging, and home refrigeration units were beginning to appear on the market. Refrigerators of those days used ammonia, sulfur dioxide, methyl chloride, and hydrocarbons as coolants - all of which are highly toxic. A number of refrigerator-related deaths during the early 1920s had propelled companies such as General Motors and Frigidaire into a search for a clean, non-toxic, non-flammable coolant for refrigerators. Just three days after he discovered ethyl gasoline, Thomas Midgley found just such a coolant - Freon.

A non-toxic, non-flammable, non-corrosive, non-odorous chemical, Freon was the perfect coolant - just what refrigerator producers had been searching for. By 1930, Freon-cooled refrigerators were changing the way America froze food - most notably, ice cream.

Freon - convenient, cheap, and safe

Household refrigerators were just entering the market in the 1920s. These refrigerators used poisonous gases as coolants, and caused several deaths. Their dangers led to the discovery of Freon, a nontoxic coolant. Image from the Association of Home Appliance Manufacturers.

With a convenient, cheap, and safe coolant like Freon available, several companies began putting out specialty freezers designed to make large batches of ice cream at once. Operating such freezers was very time-consuming. Since there were no automatic controls, ice cream freezers had to be operated constantly by a technician in order to produce anything. Realizing that automation was the way of the future, most ice cream manufacturers dispensing freezers focused all their efforts on making the freezers fully automatic. By the late 1930s, ice cream freezers not only made the ice cream automatically, but dispensed it at the pull of a lever right into an awaiting cone.

Ice cream automation did not stop there. In 1936, an inventor named Earl Prince took the idea of automated ice cream production and expanded it to milkshakes. He invented the Multimixer - a five-spindled mixer that could produce five milkshakes at once, all automatically, and dispense them at the pull of a lever into awaiting paper cups. Prince's invention was a hit, and soon he was selling more milkshakes than he had ever thought possible - and buying more paper cups than he ever thought necessary.

Fortuitously, Prince bought the paper cups to hold all his milkshakes from a middle-aged salesman named Ray Kroc. Witnessing the speed and efficiency of the Multimixer, Kroc was convinced he had found the next revolution in food service. He immediately mortgaged his home and sold everything he owned in order to purchase exclusive rights to the Multimixer milkshake maker from Prince.

Kroc quit his job selling paper cups and, for 17 years, traveled across America selling the Multimixer to milkshake-dispensing restaurants. Business was sparse, which is perhaps what made Kroc notice a large order from Southern California. Interested in what kind of business would need eight Multimixers - or 40 milkshakes at one time - Kroc packed his bags and headed for California.

A fortituous encounter with the McDonald brothers

Ray Kroc, once a paper cup salesman, founded the McDonald's fast-food empire in the 1950s. Photo courtesy www.mcdonalds.com.

In 1954, Kroc found the McDonald brothers in a hamburger stand in San Bernadino, Calif., where they were producing 40 milkshakes at a time and selling hamburgers just as fast. Dick and Mac McDonald ran an unusual kind of hamburger stand - the menu was small and inexpensive, and people had to get out of their cars to be served, unlike the traditional drive-in. Kroc, excited by the efficiency of the McDonald's stand, suggested the brothers open a franchise. Dick and Mac, already overworked at their single stand, asked him, "Who would we get to run them for us, though?" to which Kroc replied, "Well, what about me?"

In 1955, Kroc, already 54 years old, opened the second McDonald's restaurant. By 1959, Kroc and the McDonald's Corporation had opened 100 restaurants; by 1963, there were 500 restaurants, and more than one billion hamburgers had been sold. The Big Mac® was introduced five years later. By the time Kroc died in 1984, he had opened more than 7,000 McDonald's restaurants worldwide and sold more than 50 billion hamburgers. Today, there are more than 15,000 McDonald's restaurants in 80 countries on six continents.

From first flight to billions and billions served

By the time Kroc died in 1984, he had opened more than 7,000 McDonald's restaurants worldwide and sold more than 50 billion hamburgers.

The events following the Wright brothers' 1903 flight changed the world in more ways than we usually consider. The first flight opened up new avenues for the military and new fuel problems. The fuel problems led to the invention of leaded gasoline, a double-edged sword that has allowed the development of modern motors and major pollution problems. Leaded gasoline fueled the discovery of Freon - a compound that has made air conditioning and refrigeration possible, and has ripped a hole in the ozone layer. From Freon, we also gained ice cream dispensers, and the milkshake makers that made Ray Kroc and the McDonalds brothers rich.

Today, you can easily fly to North Carolina in an airplane - an airplane made possible by two inventive bicycle repairmen, powered by an engine that evolved from the use of leaded gasoline, in an air conditioned cabin cooled by non-toxic Freon. You can drive out to Kitty Hawk in a car whose engine doesn't knock violently. And, once there, you can eat ice cream from an automated ice cream dispenser and a Big Mac® at the McDonald's that overlooks the hill where the Wright brothers launched the first airplane almost 100 years ago.