This week's Unplugged Project idea was yarn or string.
I gratefully delegated this one off to my husband who included both boys in the making of a pulley. I guess I should not have been surprised they managed to incorporate their favorite toy into the picture. They used the train to power their first-class pulley. I was called when they were ready for photos.
This was inspired by a book we got from the library: Pull, Lift, and Lower by Michael Dahl.