Friday, August 31, 2012


One of Sam's lessons for this unit was on refraction. I list it here mostly so I can include this picture:
of Abe reacting delightedly to Sam showing how the markers were reversed, and upside down, through the glass. We love our Daddy classes!
Here's Abe's drawing of refraction
And Seb's

Reservoir cookies

This was a spur-of-the-moment idea I had one day when we didn't have many activities planned. I told the children we were going to make reservoir cookies! They are just kiss cookies with ganache filling instead of kisses. :) Of course you could use any kind of thumbprint cookies, but I'm not as fond of the "butter/shortbread cookie" as I am of peanut butter, so this is what we did. I see I haven't posted the Kiss Cookie recipe before, so here it is, modified for "reservoirs":

Reservoir Cookies

2 sticks butter or margarine (1 cup)
1 cup peanut butter
1 c. sugar
1 c. brown sugar
2 eggs
2 t. vanilla
3 c. flour (about 15.8 oz.)
2 t. baking soda
1 t. baking powder
1/2 t. salt

Roll dough into balls, then roll in sugar. Bake at 375 for 9 minutes. Immediately after removing pan from oven,  make an indentation in the middle of each cookie with your thumb (it didn't burn me, but maybe I'm strange) or a small lid (e.g. from a lemon juice or vinegar bottle). Pour chocolate filling (see below) into each hole to make a tiny reservoir or lake. For more complicated reservoirs, make bigger cookies and add chocolate chip dams, incoming tributaries, etc.

Chocolate Reservoir Filling:
1 c. chocolate chips or semisweet chocolate, chopped
1/4-1/2 c. evaporated milk or cream

Combine chocolate and 1/4 c. of milk or cream in glass bowl and microwave for 1 minute on high. Stir until smooth and glossy. Keep adding milk or cream and stirring well until the consistency is spoonable, but not too runny. You can also add 1 t. of corn syrup for glossiness, if desired.

The real fun of this came in making bigger cookies that could convey more complicated data! We made a sample of each main type of dam, embankment dams and masonry dams.
Here is Abe's

And Seb's, an Arch Dam

Oh how we enjoyed gobbling these up!

Saturday, August 25, 2012

Flaming Gorge Dam

The culmination of our study of dams was a trip to Flaming Gorge Dam in Eastern Utah. Upon looking up our route on the map the day before we left, we were excited to see there would be two other dams and reservoirs along the way! The boys were looking out for them with their beady little eyes the whole time we drove. Here is the first, a small embankment dam called Mountain Dell, I think?
So lovely in the morning light!

And the next, also embankment, was Echo Dam and Reservoir. The water level here was really low!

We were also pleased to spot lots of windmills as we drove!

Flaming Gorge itself is gorgeous! (ha ha) It goes on for miles (we didn't nearly drive around it all)

We enjoyed driving across this bridge as we got close

From the top, the dam isn't that huge---I assumed the water wasn't that deep, maybe 100 feet or something. But once we got around to the other side . . . 

we could see that estimate was way off! I think our guide said it's 500 feet high. It's even a bit longer from side to side than Hoover Dam---though much, much shorter in height!

It was so exciting to see all the parts of the dam---we could hardly believe that the tour let us go into the powerhouse and see the generators at work! The children were SO curious about everything (the guide said she'd never seen children like them---er. . . I believe her exact words were that they were the "most dam knowledgeable" kids she'd encountered on this tour. Ha ha. :))
Power lines. It was stormy, and not too comforting to hear another guide tell ours as we left for our tour, "Just make sure you don't get hit by lightning!" This impressed the children greatly, and when they asked if the dam had been hit by lightning before, our guide replied, "Oh yes---lightning has hit the dam, the powerlines, the visitor's center---we all ended up on the floor after that one!" It added a delicious thrill to our visit.

Looking down

Sluice gates, leading to the penstocks

Inside the powerhouse---three big generators!

Malachi. That dark grey shape in the background is an old turbine.

Looking up from the bottom

These were interesting---hollow jet valves, I think they were called? They're an alternate release system, in addition to the spillway. They can bypass the turbines and let water out here if they need to work on the generators or release water pressure a bit. Our guide said these were in use all last summer. The spillway (not pictured---it's higher up), on the other hand, has only been used once, in 1983!

Here's the end of one of the diversion tunnels they used while constructing the dam

Reservoir from above

And, looking the other direction, the top of the dam

It was a great field trip, well worth the long drive and the late night getting home---especially since we got to enjoy views like this as we drove!

Thursday, August 23, 2012

Building dams on beach

We were really excited to get to studying dams, because that was one of the whole reasons we did this unit: the children (especially Seb) love dams! Our previous study of water pressure and waterfalls and mills made it really easy to understand the potential energy that can build up in a head of water. We drew lots of diagrams of how dams work:
One of Seb's diagrams
I wanted to have the children make a dam, but wasn't sure where to get enough sand/mud to make it fun. Finally realized the beach would be perfect (we brought some of our own gravel and big stones to use with the sand). It was so fun to watch all the different models everyone came up with, and the modifications they made as they discovered what worked and what didn't! Next time we will also bring large tongue depressors to use; I saw a video using those and popsicle sticks, and it looked like they worked quite well.

We did have one casualty to this activity: my large square rubbermaid container, which apparently floated out to sea. Other than that, we had a great time! :)
Such busy workers!

Junie was quite, some would say TOO, brave and independent at the beach. She went everywhere! When she spied these ducks, she took off like a shot after them, quacking frantically as she went. I had to run to catch her so she wouldn't follow them right into deep water!
"You are not a duck!" I said, and this was her sad response.

This was quite an effective dam---using my good cake pan, of course

Directing the flow

Is this baby wearing brown leg warmers?

This was another day---we built an arch dam with clay and cardboard, to measure the strength of different arch arcs (?) and determine which type of arch held the most water before failing. Very interesting.

One night this week we also watched David Macaulay's documentary Building Big: Dams. It's excellent; one segment of a 6-part series which we hope to watch the rest of sometime. We got it on Netflix.

Monday, August 20, 2012

Benson Grist Mill

This field trip was such a happy surprise. While we were learning about mills and waterwheels, we watched a video of a working grist mill in Virginia. I had planned to go see the old waterwheel at Gardner Mill, but after we watched the video I did a quick search to see if there were any other working grist mills around. (We have the Lehi Roller Mills, but I couldn't find any tours available there, and anyway they use rollers---not waterwheels!) It seems like there are actually very few actual working waterwheel mills in the country anymore, but the Benson Grist Mill came up on my search, described as a "historic mill." On the spur of the moment, we decided to hop in the car and drive over there. It's about 45 minutes away from our house, over the mountains to the west.
Windmill by an old feeding trough (made of a log!)
It was 2:00 on a Monday afternoon, and the place was absolutely deserted, except for us and the sweet old lady that led the tours. She took us (with no apparent concern) into the rather decrepit-looking old mill, where we were thrilled to find much of the original machinery still present! It was so cool to see all the components we'd just been learning about. We scrambled up and down the stairs (hauling Junie's stroller up when possible) and the children hit our guide with barrages of questions.
A look into some of the grain elevators---such an ingenious system!
Some of the old leather belts that pulled the elevators, before they were replaced with stronger materials
I kept the foreground really dark in this picture so you can see the old waterwheel through the window in the background (this one was all broken and falling apart)
Seb by a machine called the "bug and dust collector"
Some later equipment---these are rollers like they use at the Lehi Roller Mills
Gears originally connected to the waterwheel and the turning shaft
Mill from the back---you can see the old waterwheel really leaning to the side
The millpond is all green and swampy, but I thought it was pretty nonetheless
One of the millstones---I think this was the bed stone

So that was fascinating, and then as we were all bemoaning the fact that we couldn't see the waterwheel actually working, our guide said, "Well, we can go next door and see the one there." What?! It turns out that in 2006 they built a working replica of the mill that shows how the wheel actually turns the millstones. We could hardly believe our luck.
First our guide showed us this small hand-grinding mill (which was itself quite an improvement over the mortar and pestle!). You pour the wheat in the center, and it falls through the chute after being ground by the stones. It falls onto a screen which you shake to sift the flour into a compartment below.
Seb could have done this all day, and tried to, until our guide had to gently urge us onward

Then she turned on the waterwheel, and the gears and shafts and millstones all began to turn. I know it seems silly, but we were all giddy over it---having been wanting to see this so much! I believe someone may have started clapping. (I think that was Junie, actually.) Above you can see the gears attached to a shaft below, turning the belts . . .
which turn the run of millstones! You can see the runner stone on top, whirling merrily.
Another too-dark picture, so you can see the water emerging from the flume---this is an overshot waterwheel, the most efficient type---and falling onto the wheel.
Here is the view from the back
And another view
As a bonus, there are several old pioneer cabins, a blacksmith shop, etc. at this site, and we enjoyed seeing them too. Our guide took off the ropes on the doors of the cabins and let us wander around inside (she had taken quite a liking to the children by this time, thanks to their interest in her tour!) so we could see everything. Seb and Abe found this barbed wire exhibit particularly interesting---we learned there are something like 500 kinds of different barbed wires!
We learned that there are events at this place several times a year, and we hope to return when they are actually grinding corn into cornmeal in September! It was one of the best field trips we'd been on, and we talked happily about it all the way home.
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