Building a Civil War Pontoon Bridge

Do you know what a pontoon bridge is? I didn't before this unit, but as soon as I read about them (they are basically temporary floating bridges that can be built quickly---they were used frequently in the Civil War and were especially important in the Battle of Fredericksburg, among others) I knew we had to build one. It's exactly the type of thing the boys are most interested in. Perhaps not surprisingly, when I searched online for things like "Build pontoon bridge for kids," no results came up. :) So we were on our own. 

We learned about Civil War pontoon bridges at this website.

There are some great photographs here.

This article had really interesting information about pontoon bridges today (Washington State has a whole bunch, and is currently constructing the world's largest pontoon bridge).

This video shows a pontoon bridge failing (what's an engineering lesson without a bridge fail video?)

After finding out what components made up a pontoon bridge (this site was most helpful for methods and terminology), we brainstormed options for building materials. Pontoons are basically like big floating boats, so we used water bottles as our pontoons. We used skewers for the long floor timbers (called balks and side rails) that lie across the pontoons. Popsicle sticks worked well as the chess planks, and we just used yarn for lashing everything together. I wanted to do everything with lashing, but it was just too hard to lash the popsicle sticks securely enough, so we did use a layer of duct tape to secure them to each other, and then lashed that to the balks beneath.

We needed water to build our bridge across, so we took our supplies and relocated to a nearby park with a stream in it. I was sitting against a tree feeding Marigold most of the time, so I told the three boys they were on their own to build the thing. "Use square knots!" was the extent of my advice. (There are probably better knots for lashing, but what do I know? We need to do a unit on knot-tying.)

Gathering materials

I was really impressed with their persistence and cooperation. Malachi got distracted and started playing in the stream a few times, but the two older boys worked pretty tirelessly.

Assembling the pontoons

Measuring the width of the stream

Creating long balks from two shorter skewers

Lashing the balks to the pontoons

Adding the chess planks

Because we were working between rocks instead of dirt riverbanks, we couldn't really do the abutment part of the bridge. The boys just secured the yarn beneath two rocks.

I told them the bridge had to support the weight of some soldiers and some artillery without sinking, and that it had to be sturdy enough not to float downstream or break apart.

Success!

This was a really fun project and we all gained a new appreciation for the Army Corps of Engineers, who constructed these bridges under heavy fire and in all kinds of miserable conditions. Hooray for pontoon bridges!

Civil War Weapons, and Making an Air Vortex Cannon

Artillery Guns! How we love them. In fact, Abraham chose to do his Final Project on Civil War Artillery. They are really quite fascinating. We also became very interested in muskets and small arms. Did you know, for example, that rifling refers to the spiral grooves inside the barrel of a gun, which help the bullet spin and therefore go farther and straighter? Some older muskets used in the war were smoothbore (non-rifled) and didn't work nearly as well. This video shows a musket firing in slow motion---you can see the flash as the initial charge, and then the powder in the barrel, ignites. So cool! And here is a website that was very informative.

We made this chart during our discussion---there is a lot of weapons vocabulary that I never knew before! I never thought I could be so interested in guns.

We watched the end section of this video, which shows how a team of artillerymen loaded and fired cannons in the Civil War. (And we got to see real cannons fired here earlier!) Cannons are just one type of artillery gun, we learned. There are also howitzers and mortars, which have a higher angle of fire and usually fire shells instead of solid shot.

Anyway, I thought the perfect activity for our weapons day would be to make a cannon of our own---an air cannon, of course! We tried a couple designs (this was our first attempt) and thought this one worked the very best. (It is also the simplest; all you need is any size box, and packing tape. You cut a round hole in one side of the box, tape up all the other sides so no air can escape, and you're all set!)

Air cannons are so fun. We tried filling ours with flour and shaking it up to see if we could make the vortex visible, but it didn't work too well. We considered putting a candle inside to make smoke, but it seemed like too much trouble (and I didn't want to light the box on fire).

You can see a slight ring of flour dust in front of the cannon's hole

We had a great time playing around with our cannon. It was pretty powerful even with such a small box! Next time we get a package in the mail we're going to use the box to make a bigger cannon.

Flying cups!

It was also fun to shoot at targets from opposite sides at the same time

Abraham Lincoln and a Log Cabin craft

While I was reading up on Abraham Lincoln for this unit, I kept thinking how overdone the whole Log Cabin thing is. Don't we know anything else about Abraham Lincoln?, I kept wondering. But . . . then I wanted to listen to Copland's Lincoln Portrait, and it seemed like a craft would be the perfect thing to keep everyone busy and quiet while we listened. And then I ran across a blog post about a 3-D log cabin, which seemed way more fun than the usual 2-D ones I remember making in 2nd grade. So we did it. And it was fun.

We found some really excellent children's books about Lincoln, too. He is one of my heroes, and I love reading about him. Here are some of the books we liked best:

Lincoln Tells a Joke

Mr. Lincoln's Boys

Abe Lincoln Loved Animals

I liked the way these books focused on some lesser known aspects of Abraham Lincoln's life (besides the log cabin, ha ha) and gave some insight into his character. Plus, they were charming (the animals one is adorable---he rescues baby birds!).

As a barely-related (but very interesting) side note, we watched this video showing the odds that we, in our hot cocoa this morning, drank some of the same molecules Abraham Lincoln drank in his coffee the morning of his Second Inaugural Address! :) Fun.

To make our log cabin, we followed the pattern here. We used the hot glue gun and as you can see, both boys are holding ice packs on their fingers here. It's about time someone besides me got burned with that thing!

We glued a portrait of Abraham Lincoln above his door. And made him a little park bench to rest on.

Honest Abe

Winslow Homer and Wood Block Printing for Kids

I really like the paintings of Winslow Homer, so we took a day to learn about his life and study some of his art. My favorites are the paintings he did later in life, like these:

But during the Civil War, he worked as an artist for magazines and newspapers, sending home scenes from the front lines. He's well-known for his wood engravings during this time, like this one:

So I thought we would learn about the process of wood-block printing, and make some wood-block prints of our own. You could also do this with potatoes---there's not much room for detail on a potato, but we didn't get too complicated with our designs even in the wood, since I mostly wanted the children to understand the process itself.

I bought some odd-sized pieces of balsa wood (very soft) at the craft store.

Taking our inspiration from here, we gathered a bunch of random household objects (keys, allen wrenches, etc.) and secured them lightly to our wood with packing tape. Then I had the children hammer the objects down into the wood until the impressions were pretty deep.

The older boys also used pens and screwdrivers to chisel/carve other designs into the wood.

We painted a light coating of black paint on top of each piece of wood. You have to be careful not to get globs of paint into the grooves of the design you just made. A sponge brush works pretty well for this.

Then we placed a clean sheet of paper on top of the painted side of the wood, and rolled along the opposite side of the paper with this toy rolling pin. You can make a couple of prints with the same wood block before adding more paint. Sometimes the second print is better because the paint isn't quite so thick! I like it when you can see the grain of the wood in your print.

We talked about how this style of printing made the widespread distribution of art possible, by allowing one painting to be copied many times with very little trouble or expense. We also talked about the skill it would have taken to make such detailed engravings, even if you were just copying art someone else had created!

I really liked how these turned out---each print really had its own character!

Civil War Spies and Ciphers

Who doesn't love a good code? We talked about communications in the army, and various codes and ciphers used by the Union and the Confederacy. We also read some great books about Civil War spies---I think our favorite was Sarah Emma Edmonds was a Great Pretender. At one point she was a girl, pretending to be a man in the Union army, pretending to be a female slave in the Confederacy! Amazing.

We had a great time writing secret messages to each other using cipher squares. You can find instructions on this here. The concept is simple, but the codes are surprisingly effective!

Morse Code Treasure Hunt

My friend Andrea had a brilliant idea for demonstrating that knowing how to read gives us power (and for helping the children think about how frustrating it must have been for the slaves who didn't know how to read). Her idea was to write out clues for a treasure hunt in Morse Code, and show the children how without knowledge of that "language," it's impossible to make progress toward your goal (the treasure).

I loved this idea and we executed it pretty much just as she did. We read this and this, both stories about how valuable literacy was to the slaves. We talked about Frederick Douglass' statement, "Once you learn to read, you will be forever free," and we read excerpts from his autobiography. Very inspiring.

The treasure hunt was a small one, just around our house and yard, and up and down the street, but the children were very excited about it. The older boys loved learning Morse Code and insisted on writing it (and tapping it on doors, and flashing it with lights) all the time for the next several days.

I had some Civil War soldier figures that we were going to use later on in our unit, so I put those in the "treasure box" at the end of the hunt, along with little notebooks I found in the dollar section at Michael's. The notebooks were surprisingly well-received; they weren't really anything special but the children seemed to think they were. We talked about how lucky we are to have access to all the books and paper and pencils we could ever want!

Battle Re-enactment

I thought this was a great idea, from the book The Civil War for Kids. We drew out a large map of important landmarks near a battle (we did the Battle of Chancellorsville) and then the children moved our toy soldiers around to the relevant locations, as I read to them the events of the battle. We did this on the day we talked about the biographies of Robert E. Lee, Ulysses S. Grant, George Meade, and others. It seemed like a good way to realize how many decisions the General was responsible for, and how complicatedthose decisions might be (taking into account limited troops, blocked-off supply routes, river crossings, etc.).

Military Ranks and Drilling

We talked a lot about what daily life was like for a soldier, and one of the main things they did was DRILL! We watched this video showing how many steps were needed to load and fire a musket. You can see why drilling would be so necessary, especially for soldiers who had never handled firearms before!

I read about some of the drill commands (you know, things like "Forward, March!") here. Then I made everybody march around the yard with their muskets.

Ready, Aim, Fire!

I love this---Junie running to catch up :)

We also discussed the different divisions of the military, and various ranks that soldiers could achieve. This was all new to me, and the boys found it quite fascinating too. To help us understand how 2 platoons make a company, 2 companies make a battalion, 2 battalions make a regiment and so forth (we had a book that told us these things) we made an army with Hershey's Kisses and used different colors for the different officers. It was a good way to visualize what we were learning.

This site was also useful (it talks about ranks in the Civil War and shows the insignia for each; my children love stuff like this).