Nothing better for a boy and his dad to work on a nice summer project, and this year was the marble roller coaster. On the surface this looks pretty simple, but actual construction was problematical at best as many items had to be considered. After several hours, and help from Kitty Thelma, we were finally able to make the thing work and video taped it as proof because we suspect not too many people would have the patience to deal with this thing.