Compass has a half-life of only about 12 years, so a compass that contains 120 mCi of tritium when new will contain only 60 when it is 12 years old, 30 when it is 24 years old, and so on. Consequently, the illumination of the display will fade. Mariners' compasses can have two or more magnets permanently attached to a compass card, which moves freely on a pivot. A "lubber line", which can be a marking on the compass bowl or a small fixed needle, indicates the ship's heading on the compass card. Traditionally the card is divided into thirty-two points
How Many Birds How Many Birds "How Many Birds" is a song written by Barry Gibb, recorded by the Bee Gees in 1966 for the "Spicks and Specks" album. Recording took place at St. Clair Studios, Hurstville outside Sydney. The song was recorded on one-track tape machines and required the use of sound-on-sound for all overdubs. "How Many Birds" was recorded around April and May 1966 as part of the sessions for what became the Spicks and Specks album. The song starts with a guitar riff and the chord became E as Barry sings the introduction. After Barry sings the lines, the song