Calvin and Hobbes by Bill Watterson for August 29, 1989
Hobbes: How are we going to invent a robot? We don't know anything about machines. Calvin: Maybe you don't. It's easy. There are just four simple machines to alter force: The lever, the pulley, the inclined plane and, um, the internal combustion engine. Take my word for it, I'm an expert at inventions. Hobbes: So where do we start? Calvin: We ask mom for a research grant.