Turning A Problem Around: The Whitney Cotton Gin

February 7, 2020 by Al Williams 38 Comments

If you went to elementary school in the United States, you no doubt learned about Eli Whitney’s cotton gin as an example of how the industrial revolution took previously manual processes and replaced the low-efficiency of human labor with machines. The development of the cotton gin — patented in 1794 — involves an interesting lesson about solving engineering problems.

Farmers in the southern United States had a big problem. Tobacco was a cash crop, but it eventually left your fields barren and how to solve that problem wasn’t understood yet. Indigo was valuable for dye, but the British were eating away that market with indigo created in its colonies. Rice requires a lot of water and swamp, so it was only suitable for certain areas.

There was one thing that grew very readily in much of the land: cotton. Unfortunately, the cotton had little seeds you had to remove. A single person could clean — maybe — a pound of cotton a day. In the late 1700s, plantation owner Catharine Littlefield Greene introduced Whitney to a group of farmers were trying to decide if there was a way to make cotton a more profitable crop.

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Stinger: The Hacked Machine Gun Of Iwo Jima

February 3, 2020 by Tom Nardi 55 Comments

During the Second World War, the United States was pumping out weapons, aircraft, and tanks at an absolutely astonishing rate. The production of military vehicles and equipment was industrialized like never before, and with luck, never will be again. But even still, soldiers overseas would occasionally find themselves in unique situations that required hardware that the factories back at home couldn’t provide them with.

Which is precisely how a few United States Marines designed and built the “Stinger” light machine gun (LMG) during the lead-up to the invasion of Iwo Jima in 1945. The Stinger was a Browning .30 caliber AN/M2, salvaged from a crashed or otherwise inoperable aircraft, that was modified for use by infantry. It was somewhat ungainly, and as it was designed to be cooled by the air flowing past it while in flight, had a tendency to overheat quickly. But even with those shortcomings it was an absolutely devastating weapon; with a rate of fire at least twice that of the standard Browning machine guns the Marines had access to at the time.

Six Stingers were produced, and at least on a Battalion level, were officially approved for use in combat. After seeing how successful the weapon was during the invasion of Iwo Jima, there was even some talk of putting the Stinger into larger scale production and distributing them. But the war ended before such a plan could be put into place.

As such, the Stinger is an exceedingly rare example of a field modified weapon that was not only produced in significant numbers, but officially recognized and even considered for adoption by the military. But the story of this hacked machine gun actually started years earlier and thousands of kilometers away, as Allied forces battled for control of the Solomon Islands.

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AVRO’s Project 1794: A Canadian Flying Saucer

February 3, 2020 by Al Williams 14 Comments

If you ask those of us who grew up somewhere in the 1950s to 1970s what our car would be like in the year 2020, we might have described an Avrocar. This top secret vehicle from Canadian Avro was part hovercraft and part jet-powered vertical takeoff vehicle. There were two prototypes actually made and [Real Engineering] has a short video on how the prototypes worked, how the real design might have worked, and even has a lot of footage of the actual devices. You can see the video below.

The designer, [Jack Frost], experimented with ground effect and the Coanda effect. The Canadian branch of Avro, a British company, worked with the U.S. military and if you look at it, you wonder how many UFO sightings it caused. Nothing like a flying disk 18 feet in diameter going over your backyard to make you call the newspapers. On second thought, it probably never got enough altitude for that to happen.

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Who Invented The Mouse? Are You Sure?

January 17, 2020 by Al Williams 40 Comments

If you ask most people who invented the mouse, they won’t know. Those that do know, will say that Doug Englebart did. In 1964 he had a box with two wheels that worked like a modern mouse as part of his work at Stanford Research Institute. There is a famous demo video from 1968 of him showing off what looks a lot like an old Mcintosh computer. Turns out, two other people may have an earlier claim to a mouse — or, at least, a trackball. So why did you never hear about those?

The UK Mouse

Ralph Benjamin worked for Britain’s Royal Navy, developing radar tracking systems for warships. Right after World War II, Ralph was working on the Comprehensive Display System — a way for ships to monitor attacking aircraft on a grid. They used a “ball tracker.” Unlike Engelbart’s mouse, it used a metallic ball riding on rubber-coated wheels. This is more like a modern non-optical mouse, although the ball tracker had you slide your hand across the ball instead of the other way around. Sort of a trackball arrangement.

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Tetraethyl Lead: The Solution To One, And Cause Of Many New Problems

January 15, 2020 by Maya Posch 101 Comments

From the 1920s until the 1970s, most gasoline cars in the USA were using fuel that had lead mixed into it. The reason for this was to reduce the engine knocking effect from abnormal combustion in internal combustion engines of the time. While lead — in the form of tetraethyllead — was effective at this, even the 1920s saw both the existence of alternative antiknock agents and an uncomfortable awareness of the health implications of lead exposure.

We’ll look at what drove the adoption of tetraethyllead, and why it was phased out once the environmental and health-related issues came into focus. But what about its antiknock effects? We’ll also be looking at the alternative antiknock agents that took its place and how this engine knocking issue is handled these days.

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Why Do Resistors Have A Color Code?

January 13, 2020 by Al Williams 226 Comments

One of the first things you learn in electronics is how to identify a resistor’s value. Through-hole resistors have color codes, and that’s generally where beginners begin. But why are they marked like this? Like red stop signs and yellow lines down the middle of the road, it just seems like it has always been that way when, in fact, it hasn’t.

Before the 1920s, components were marked any old way the manufacturer felt like marking them. Then in 1924, 50 radio manufacturers in Chicago formed a trade group. The idea was to share patents among the members. Almost immediately the name changed from “Associated Radio Manufacturers” to the “Radio Manufacturer’s Association” or RMA. There would be several more name changes over the years until finally, it became the EIA or the Electronic Industries Alliance. The EIA doesn’t actually exist anymore. It exploded into several specific divisions, but that’s another story.

This is the tale of how color bands made their way onto every through-hole resistor from every manufacturer in the world.

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Hide Silent, Hide Deep: Submarine Tracking Technologies Of The Cold War

January 10, 2020 by Al Williams 48 Comments

All through the cold war, there was a high-stakes game of cat and mouse in play. Nuclear powers like the United States and the Soviet Union would hide submarines armed with nuclear missiles underwater. The other side would try to know where they were so they could be targeted in the event of war. The common wisdom was that the United States had many high tech gadgets to help track enemy submarines, but that the Soviet Union was way behind in this area. This was proven false when a Soviet Victor-class boat followed a US missile submarine for six days. Now, a recently declassified CIA report shows how the Soviets didn’t use sonar at all but developed their own technology.

There is something fascinating about submarines. Like an old sailing ship, submarines are often out of touch with their command bases and the captain is the final authority. Like a space ship, the submarine has to survive in an inimical environment. I guess in all three cases, the crew doesn’t just use technology, they depend on it.

Although the submarine has some non-military uses, there are probably more military subs than any other type. After all, a sub is as close to a cloaking device as any real-life military vehicle has ever had. Before modern technology offered ways to find submarines using sonar or magnetic anomalies, a completely submerged submarine was effectively invisible.

There was a lot of speculation that the Soviet Union lacked sufficient technology to use sonar the way the US did. However, in some cases, they had simply developed different types of detection — many of which the West had discarded as impractical.

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