Category: Engineering (page 2 of 2)

Things of Science #222 — Atomic Energy

Things of Science 222.1

Back in the 70’s, there was one year when I got a subscription to Things of Science. What a fascinating, nerdy thing that was.

If you haven’t heard of Things of Science let me explain to you what it was. Every month you received a small blue box in the mail that contained a booklet and often some other small items. The booklet would explain some scientific or mathematical concept and the small items in the box would be used for a series of experiments explained in the booklet. It was a sort of lab science lesson in a box.

One month the topic might be probability and the items in the box would be a pair of dice and some colored tokens. The experiments would involve the dice, etc. If you followed the instructions in the booklet you might learn quite a bit about probability by the time you finished.

Next month is might be about plants of some kind and the box would contain seeds you can plant.

One that I received that stands out in my memory was about Xerography. I now know that the mysterious black powder that came in the bag (in addition to a sheet of acetate and some sheets of white paper) is what we call printer toner. I remember the final experiment had you building up a static electrical charge on the acetate and then “writing” on it with dish soap (not included). Then there was a step where you transferred the electrical charge to a sheet of blank paper. I believe you sprinkled the toner over the sheet of paper and, lo and behold, the toner was attracted to an area on the paper representing the image you had “drawn” with  dish soap. The final step to cure the image involved using a clothes iron (also not included)  to melt or fuse the toner to the paper. I was blown away to see it actually work.

I no longer have my Things of Science units I’m afraid. I have since though picked up a few from eBay. One older unit I picked up involved Atomic Energy (unit #222). Unfortunately the kit was not complete and the uranium oxide and lead sheet were missing.

If a teacher wanted to re-create this unit for the classroom, there are going to be modern difficulties.

The unit begins with experiments in electrostatic (static) electricity. For this you need:

  • 2 balloons
  • Thread
  • A sealing wax rod
  • Saran wrap
  • Either fur or wool

They then move on to constructing an electroscope. For this they suggest:

  • a glass jar
  • a length of stiff copper wire
  • foil (from chewing gum wrapper)
  • a penny

You can throw money and buy an electroscope for about $30. Or search around the internet for a tutorial (if the booklet below doesn’t describe it well enough for you). Here is one I found with a few minutes searching: build a simple electroscope

Soon though the unit calls for Uranium Oxide impregnated paper (the radiation source). I have not found an inexpensive source for this. Nonetheless, I am aware that home smoke detectors contain a radioactive source (Americium, I believe). You can easily get a cheap smoke detector or an old one and open it up for it’s radiation source. While I haven’t tried the experiment in the unit by substituting the radioactive source from a smoke detector, it seems like it should work.

Perhaps you have access to an old watch with a radium on the tips of the hands?

The unit talks about autoradiographs and while do-able (again, if you can find an adequate radiation source) photographic film and the means to develop it are getting to be a more difficult hurdle to overcome. There was a time of course when schools (well, middle schools and high schools anyway)  probably had a darkroom and the necessary film and chemicals. So perhaps autoradiographs can be skipped.

The unit discusses cloud chambers. Building one of these is not as simple as an electroscope. But the construction is discussed. But also, like the electroscope, there are plenty of sites on the internet that detail building a cloud chamber. The chamber should not be expensive to construct and if you do build one, the result of operating one is fascinating.

Here is a page showing how to build a cloud chamber. It was one of the first ones I clicked on.

The unit describes a spinthariscope and how to build one. A double-convex lens is easy to find (a magnifying glass) but the activated Zinc Sulfide will have to be ordered. I found a place that sells the Zinc Sulfide for $10. It turns out they also sell a completed spinthariscope for $35.

Finally, the unit discusses the Geiger counter. They give an electronic parts list and a schematic but it really shouldn’t be attempted by anyone not extremely familiar with electronics. It uses mains-power (household current) and can be dangerous to use if incorrectly wired. Instead, if you have $99 to spare, a clever, modern kit like this one would be a fun addition to a science classroom.

Here is a scan of the booklet that came with this unit:

Things of Science #222 — Atomic Energy

More Things of Science scanned here.

The Boy Mechanic

Boy Mechanic 1

It’s difficult for me to describe the magic I felt the first time I came across an old volume of “The Boy Mechanic” at the house of a friend of the family. I was young, perhaps ten or eleven years old, and already had a knack for seeing how things worked. Even at that age, I loved making things (though I had very few resources and tools). And so then here, suddenly, was this big, heavy, thick old book that showed all manner of amazing things a handy “boy” could make.

Clearly the book was old. Some of the contraptions required access to barrel staves, buggy springs … things from an earlier time. Nonetheless, it was chock full of clever things you could make with ordinary hand tools, access to the sort of odds and ends of the time, and a lot of patience, free time, and some degree of skill.

Many of the projects looked fun. Some even looked dangerous!
Boy Mechanic

And, I soon discovered, the family also had additional volumes of “The Boy Mechanic” that were published afterward. They were just as thick and just as crammed with projects, and ideas. In fact, the first run of “The Boy Mechanic” included four volumes.

Unfortunately, for me, I was unable to borrow the books and had to content myself with poring over them when our family came over to visit. Because of the books age (already about seventy years old at that time) I was not able to find them in the library to check out.

Eventually, when I got older, I tracked down some of the volumes in used book stores and purchased them. Eventually too I found reprints of the first four volumes and purchased these as well. I also discovered that the original four volumes were not the last of “The Boy Mechanic” that had been created — new editions with new projects and crafts were printed sometime around the 50’s.

I will share some of the amazing things from these books in some of the postings that follow. Maybe, if these books are new to you, you can show them to someone young and creative in your life and perhaps they too will get some of the inspiration that I did.

In this day and age, it is unfortunate that the books specify a gender in the title. Maybe when you present the series to a young person you can simply describe the books as The Young Mechanic.

The original “The Boy Mechanic, Vol. I” was published in 1913 and so is well outside of copyright. For this reason it is easy enough to find a copy of the book online for free. Here is one such link:

And also “The Boy Mechanic, Vol. 2”:

The Automobile Transmission

Especially with the popularity of cars with automatic transmissions, many drivers today may forget that there are complicated systems of gears that transmit power from the car’s engine to the car’s wheels. Drivers that can work a clutch and a stick shift are certainly aware of a cars gearing but may be clueless as to how it all goes together.

An educational film from 1936 shows how an automobile’s gearing is put together.

When the film begins, it describes the lever and its mechanical advantage. Soon however the subject turns to gears and the modern (for 1936) automotive transmission.

The gearbox they detail, which was standard at that time, is merely a three speed transmission (plus reverse) and yet it is already fairly complex. It boggles the mind what a modern seven speed gearbox must resemble.

I don’t believe it is the case any longer that public schools offer vocational classes. I remember in middle school (junior high) I took a wood shop class. I enjoyed that experience a great deal. They offered metal shop and automotive shop classes as well.

I imagine the following film might have been shown in an automotive class. It’s wonderful how it describes the problem and then the solution that differential gearing provides in a way most students can probably understand.

An educational look at how things work. More films like this, please.
(The actual education content begins about 1:55 into the film.)

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