Using the left mouse button, select piece and drag into position. Pressing the right mouse button rotates piece. If you need a hint, press the "V" key to view the whole image. Change the number of pieces: 9 | 24 | 48 | 160.
An anvil crawler is a lightning discharge occurring within the anvil of a thunderstorm, characterized by one or more channels that appear to crawl along the underside of the anvil. They typically appear during the weakening or dissipating stage of the parent thunderstorm. To discover more about lightning, go to JetStream - an Online School for Weather.