The Rainmaker is a machine from Forestry that, when placed, will wait for the player to give it an Iodine Charge. Once done, the Rainmaker will do as th name suggests: makes it rain. This can be used to fill Raintanks, rather then just waiting for it to rain. Rain showers are cleared up with a Dissipation Charge (as of version 1.4.4). The Rainmaker does NOT need power to operate.