The clever part of the wheel is the axle. Seeing a stone rolling down a hill might lead to rolling a load on logs for transport. Funfact: the first wheels were

The clever part of the wheel is the axle. Seeing a stone rolling down a hill might lead to rolling a load on logs for transport. Funfact: the first wheels were potter's wheels. https://www.smithsonianmag.com/science-nature/a-salute-to-the-wheel-31805121/ https://www.smithsonianmag.com/science-nature/a-salute-to-th... My favourite early invention is cloth. Fire's not really an "invention" in the same sense, more like taming wolves and horses.