A clock certainly seems nothing like a ruler. Yet, a clock and a ruler do the same kind of job. They both measure something. A ruler measures length and a clock measures time. People of long ago...
African thumb piano
Materials - crosscut saw - glue (white) - hand drill with twist drill bit - ice-cream sticks (four) - lumber (\^ inch plywood, scrap blocks, and thin strips) - pencil - ruler - sandpaper -...
