Robert Patch of Chevy Chase, Md., was only 5 years old in 1962 when he designed a toy truck that could be converted into a flatbed or a dump truck by altering the placement of the axles. His father, a patent attorney, saw that the truck’s design was unique enough to be patentable, so Robert signed the application with an X and had the mark witnessed by a notary public. When the application was granted, Robert became the youngest person in history to receive a U.S. patent.

The publicity meant nothing to him, but it did bring one benefit. He had made his working model from bottle caps, Scotch tape, nails, and old shoe boxes. Someone at US Keds, the shoebox brand, saw the story — and sent him a new pair of sneakers.

In 1915, Vermont inventor Albert Pratt proposed a new weapon: a head-mounted gun. You strap the helmet to your head and hold a hollow tube in your mouth; when you blow through the tube, the gun fires a bullet at whatever you’re looking at.

“The weapon described has many advantages,” Pratt writes confidently. “The gun is automatically aimed unconsciously and incidentally to the turning of the head of the marksman in the direction of the target. In self-protection, one immediately, instinctively turns the head in the direction of attack to see the enemy, or, in hunting, toward any sound made by nearby game. Thus the gun is automatically directed toward the mark in the course of the first instinctive movement. With the gun thus aimed, the only further operation necessary to fire the same is to blow through the tube and thereby expand the bulb and operate the trigger. This is accomplished entirely from the head of the marksman, leaving his hands and feet free further to defend himself or for other purposes as desired.”

“Under some circumstances the gun can be fired not only without the use of the hands and feet, but also without the use of the eyes of the marksman. For example, in hunting at night if an animal made a sound in underbrush, the head of the marksman would be instinctively turned in the direction of the sound and then the gun would be fired, without the use of the eyes of the marksman.”

If that’s not enough, Pratt also says that the helmet can be detached from its base and used as a cooking utensil. “The spike may be stuck in the ground to support the utensil or may be detached therefrom as desired.”

Fly-plagued and enterprising in 1919, G.W. Blake came up with this inventive solution. The spring-loaded pistol shoots a projectile bearing a woven wire screen fast enough to surprise an unwitting fly who might have been expecting a low-tech flyswatter.

Next I suppose the flies will start shooting us.

An ordinary umbrella wasn’t enough for Elizur E. Clarke — in 1864 he suggested adding a skirt, to render it “a more perfect protector from storms.”

The man gets a little loophole to look out of. His companion will just have to trust him.