Atmosphere of Earth (see the temperature section, below). Because the general pattern of the temperature/altitude profile is constant and measurable by means of instrumented balloon soundings, the temperature behavior provides a useful metric to distinguish atmospheric layers. In this way, Earth's atmosphere can be divided (called atmospheric stratification) into five main layers. Excluding the exosphere, the atmosphere has four primary layers, which are the troposphere, stratosphere, mesosphere, and thermosphere. From highest to lowest, the five main layers are: The exosphere is the outermost layer of Earth's atmosphere (i.e. the upper limit of the atmosphere). It extends from the exobase, which is located at
Salt of the Earth (song) Jagger and Richards using a personal tape recorder, "Salt of the Earth" was recorded at London's Olympic Sound Studios in May 1968. Featuring on the song are the Los Angeles Watts Street Gospel Choir and a piano performance by Nicky Hopkins. These additions, and their prominence near the end of the song, are further developed on their next album "Let It Bleed"'s closing song, "You Can't Always Get What You Want". "Salt of the Earth" has a unique live history. It has only been played once to an instrumental playback and live five times. Salt of the Earth (song) "Salt