These small engines were connected to a belt worn around the rider’s waist. The front of the belt contained the ignition to switch the engines on or off. The back of the belt contained a fuel tank that held less than a gallon of fuel.

Constantini motor skates never entered mass production, and the invention slowly disappeared from public consciousness. Another man named Mercier also made a motorized roller skate. But only one of Mercier’s skates had an engine.

Although little is known about the skates, Mercier claimed that they could travel at approximately 30 kilometers per hour (20 mph) for about 50 kilometers (30 mi) before they ran out of fuel.

Aside from his attempt to meld the agricultural and automotive industries, Henry Ford was forced to make a car out of soybeans because there was a shortage of metals during World War II. Ford claimed that his soybean car was stronger and sturdier than a regular steel car and could somersault without being destroyed. However, the project was canceled while the second prototype was under construction.

The vehicle had a two-wheel drive with power provided to the second set of wheels in the front. However, all four front wheels were used to make turns. Reeves claimed that his eight-wheel vehicle was better than four-wheel vehicles because the tires did not wear as easily and the vehicle had better stability.

The car failed to lure investors, but that did not discourage Reeves. He simply pruned the eight tires to six: two in front and four in back. He called the new car the SextoAuto. But the SextoAuto had nothing new to offer. Like Fuller’s Dymaxion Car, Reeves’s Overland OctoAuto earned a place on Time magazine’s list of 50 worst vehicles ever.

The Dymaxion Car was also unstable on the ground, even with the top fin on its third prototype for stability. Initially, investors wanted to fund the vehicle for mass production, but they backed down after a prototype was involved in a deadly accident. Further development of the vehicle ceased, and it currently has a place on Time magazine’s list of worst vehicles ever made.

The French Helica was quite popular. On the other hand, the Argentine Aerocar had acceleration problems up to 65 kilometers per hour (40 mph). Even so, one US car manufacturer wanted to buy the Aerocar to produce and sell in the US.

One major advantage of propeller-driven cars is their lack of gears and brakes. They are also more stable than regular cars and can run on airplane engines. Their major disadvantage is their propellers, which can seriously maim or even kill any unfortunate human or animal that dares to come too close.

It was able to maintain its balance on two wheels and did not tilt when it turned, when people leaned on it, or when people got on and off. That’s because the Schilovski Gyrocar contained a pair of gyroscopes.

Although this car never caught on, it was not the last two-wheeled gyrocar ever made. In 1967, Gyro Transport Systems came up with a single-seater gyrocar called the Gyro-X. But the Gyro-X never made it past the prototype stage because its parent company went bankrupt.

While gyrocars are generally slimmer and smaller than normal vehicles, they have never been widely adopted because the gyroscopes needed for stability are expensive and complex to build and maintain.

Due to the politics of the day, only 51 units of the car were made before production was canceled and the Tucker car company was liquidated. It all began when Preston Tucker leased a production facility from the War Assets Administration. They ordered him to raise a certain amount of capital before a particular date, or they would reclaim the facility from him.

Tucker, who did not want partners in his business, raised the funds by selling dealership rights even though the car didn’t exist yet. This caused the SEC to begin an investigation into his company. Tucker got the SEC off his back and managed to launch an unstable prototype nicknamed the “Tin Goose.”

Afterward, he began selling stock in his company. But he didn’t raise enough money to begin production, so he began selling accessories for the unmade car. This led to another round of investigations by the SEC and the Department of Justice. Tucker, along with some of his partners, went on trial for fraud and the violation of SEC regulations.

The trial focused on the highly unstable Tin Goose prototype while the 50 better vehicles that Tucker had made for the market were deliberately ignored. Although Tucker and his partners were later found innocent, it was too late to save the car and the company.