The 40th Parallel is a track from Christopher's Earthsongs album. It's all about the observation that an amazing number of important events in human history have occurred along the 40th parallel—the latitude that falls about halfway between the equator and the poles. This is the temperate zone, where winter is cold and summer is hot, and trade winds make it possible to sail across the great bodies of water that separate the continents. How we ended up on a planet perfectly designed for life, with conditions that would force us to adapt and grow is a mystery...and The 40th Parallel captures that mystery beautifully.