Generally, on a playground, there are simple, rotating merry-go-rounds powered by children. These are provided with bars which children can cling on to while going round and round. Some developing countries have made good use of these merry-go-rounds.
For instance, in South Africa, this simple amusement has been used to pump water from underground . As the kids play, the rotation of the merry-go-rounds is used to pump water from underground and store it in overhead tanks! This makes it easier for women and children to later draw water for their daily needs. So, the more fun you have on the merry-go-round, the more water you pump for use by your community. There are 700 such play pumps in South Africa alone! Don’t you think this is a great idea?
Picture Credit : Google