The gun club of "From the Earth to the Moon" and "Around the Moon" returns after a long retirement. "The Purchase of the North Pole" brings back the three explo

Discusses the issues of geomagnetism, including why the Earth's magnetic north differs from its geographic north, how animals use geomagnetism for migration pur

A classic Harold and the Purple Crayon holiday adventure picture book! Harold at the North Pole finds Harold in need of a Christmas tree and Santa in need of Ha