Chalk It Up

I'm watching Caitlin, Ellie, and Talie draw an intricate chalk roadway on the garage floor when the questions start.

"Mom, how do they make lawn mowers? How do they make cars?" I applaud Talie's curiosity, but my bumbling stop-and-start answers leave me feeling a little inadequate. At this point I'm ready to whip out one of David Macaulay's great THE WAY THINGS WORK books, until I hear the next question: "How do they make chalk?"

My face lights up. I practically shoot up my hand like a school kid who's dying to show off her answer in class. This one I know!

Better yet, I can even show her, because thankfully an engineering degree is not required. When I say this, even Caitlin and Ellie are impressed. (This is a feat. As nine-year-old fourth graders, they belong to the ruling class at school; they know most everything, of course.)

The next day I head off to the art store to load up on plaster of Paris and powdered tempera paints for our homemade chalk project. There's only yellow, red, and white tempera on the shelf, but no matter. It's the process, not the cosmetics that count here.

Back home, the weather outside is not cooperating, so we spread out the newspaper on the kitchen floor and get down to the business of mixing up water, plaster, and paint. It's a bit messy, but nothing my kitchen floor hasn't seen before. The bigger challenges are a) explaining to Talie why we're pouring the plaster/paint mixture into discarded toilet paper tubes, which serve as the chalk molds and b) waiting out the two days it takes for the chalk to dry completely.

Two days later, the weather has not improved, but no matter. Talie and I unwrap the tubes to free the chalk and head to the basement. We sketch a yellow and pink hopscotch with our new homemade chalk. It's fantastic on all counts, until Talie looks up at the boiler.

"Mom," she says, "How do they make those pipes and tanks?"