This young woman undoubtedly took home the blue ribbon in the 1960 science fair. And she certainly earned herself considerable street cred as a mad scientist by putting together this Jacob’s ladder, by carefully following the plans in the November 1960 issue of Electronics Illustrated.

As revealed by the schematic diagram below, the circuit is simplicity itself. It simply takes normal household current and runs it into a transformer which steps it up to 12,000 volts, which is fed into two electrodes. One way or another, there is going to be an arc between the two conductors. It will follow the path of least resistance, and thus starts out at the bottom, where the two metal rods are closest together.

The arc heats the air right above it, which ionizes the air. The ionized air thus becomes the new path of least resistance, and the arc moves upward. The process repeats until it reaches the top, at which point a new arc forms at the bottom.

The critical component, of course, is the high voltage transformer. In 1960, it was available in the form of a neon light transformer, for $12 plus shipping. Of course, neon signs still exist, and you can buy the transformers on Amazon.  This modern replacement is rated at “only” 10,000 volts, but it seems like that should be sufficient.

The 1960 article includes a number of important safety features. First of all, the electrodes are safely behind a sheet of 1/32″ clear acetate. This also appears to be available on Amazon.

And the choice of switch ensures that the device isn’t turned on accidentally. The power switch is a momentary switch, meaning that when you let go of the switch, it turns off. It’s a SPDT switch, meaning that when it’s off, another contact is energized. This is wired to a green pilot light that indicates that the device is plugged in. The switch has a safety cover, meaning that one needs to consciously lift the cover to flip the switch.

The article begins by saying that “if the directions given in this article are followed to the letter, there is no danger of shock. Don’t take short-cuts or omit the built-in safety features of this model; it is poor economy to leave out relatively inexpensive components that might prevent a nasty shock.”

These days, when one reads safety warnings, there’s a tendency to ignore them. But in 1960, when a warning like this was included, it’s because the activity in question was, indeed, dangerous, and you really needed to be careful. So I believe this project is suitable for mature students, working under the supervision of a competent adult. But this contraption is potentially lethal, and great care must be taken in its construction and use.  In 2016, a Michigan teen was killed trying to build one, and we don’t want any of our readers to suffer the same fate.  So please be careful.

If Junior is looking for a spectacular science fair project that can be built at little expense, but still uses a slightly dangerous chemical, he can’t go wrong building this real submarine, according to plans contained in the August 1940 issue of Popular Science.

When released in the local pond, the submarine repeatedly submerges and surfaces, all the time moving forward in the water. The secret of all of this is a small amount of calcium carbide, the same chemical used in old-fashioned miner’s lamps. When the chemical is exposed to water, it generates a high pressure gas, which is used to propel the vessel and provide buoyancy. The chemical is readily available at Amazon, and probably at your friendly local hardware store.

School will eventually reopen, so your young submariners can take advantage of their summer vacation to build and test the craft, which can be made out of scraps of sheet metal and tin cans. Soldering is required, but kids naturally enjoy working with molten lead. When school reopens and the science fair is on, the submarine can be used for a variety of scientific experiments involving buoyancy, propulsion, or chemical reactions. The teacher has probably seen old movies with miners wearing headlamps, but this will probably be their first exposure to the actual chemical used. A blue ribbon is almost guaranteed.

The young man shown here is probably getting ready to collect his first Social Security check, but fifty years ago, he undoubtedly took home the blue ribbon at the 1970 Science Fair. His project was shown in the August-September 1970 issue of Science and Electronics. According to the magazine, the project would show off knowledge and understanding, but would also require dexterity with tools.

The project was a moving-coil ammeter, not unlike a commercially made meter movement. While the magazine didn’t use the moniker, this type of meter is also commonly known as a d’Arsonval meter movement, after Jacques-Arsène d’Arsonval. For less advanced students, the article referred back to construction articles for some more primitive meters, such as the hot-wire ammeter we previously profiled. Most of the meter’s mechanical parts were made of wood, so the project required some expertise in the wood shop. The form for the moving coil was made with balsa wood, whose light weight ensured a sensitive movement.

The finished product could be accurately calibrated by using a commercial VOM, a battery, and a potentiometer. Current readings were noted on the commercial meter, and then marked on the face of the homemade meter.

According to the article, if the builder used reasonable care and followed instructions, they would be assured of a good grade and congratulations from friends and teachers.  And fifty years later, there’s no reason to think the result would be any different.

For the young scientist who wants to outsmart the science teacher, here’s an excellent science fair project that duplicates the work of American physicist Henry Rowland.

Your teacher undoubtedly knows that a an electrical current generates a magnetic field. But what your teacher probably doesn’t know is that a moving charge of static electricity also generates a magnetic field. This can be demonstrated from this experiment in the July 1940 issue of Popular Science.

To do the experiment, you set up an electric motor as shown here. You attach a disk of hard rubber, which you electrify by rubbing it with a woolen cloth. (Instead of the rubber disk, you can use an old phonograph record. If you don’t know what that is, you can ask your grandparents, or read some of our posts about the history of the phonograph).

Once the disk is charged up, you turn on the motor. As soon as it starts spinning, a compass placed nearby will deflect, showing the presence of the magnetic field.

If Junior decides to do this science fair project from the the July 1940 issue of Popular Science, he should probably change the name. The magazine calls this gadget a carbon dioxide “gun,” and he’ll probably get in a lot of trouble if he calls it a gun. If he calls it a “remote fire extinguisher,” he’ll probably get a blue ribbon instead of a visit to the police station.

Like all young men like to do, the two shown here are playing with fire, but making a scientific point in the process. In this William Tell stunt, one young man has a candle on top of his head. The other one puts it out with the Carbon Dioxide Gun–er, I mean remote fire extinguisher. Whatever it’s called, the device is simply a can with a balloon stretched over one end. Inside, a piece of dry ice is placed. When the balloon drum is tapped, an invisible cloud of CO2 is expelled, which causes the flame to be deprived of oxygen.

If you’re looking for a science fair project that can be put together with parts you’ll find around the house, you can’t go wrong with this motor from the July 1940 issue of Popular Science.

The main components used are paper clips. You’ll also need some insulated copper wire and a few other odds and ends. The old-fashioned dry cell batteries look cool, but it will work just as well with a couple of alkaline D cells.