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
Compass (Hudson) Compass (Hudson) Compass is a public artwork by American artist Jon Barlow Hudson, located above the Brady Street Pedestrian Bridge, which is in Milwaukee, Wisconsin, United States of America. "Compass" consists of mirror-polished stainless steel tubes and four different blocks of Wisconsin granite. The sculpture measures 12'h. x 10'w. x 3'd. and was installed and signed by Hudson in 2005. This abstract/geometric sculpture connects four Wisconsin granite blocks with stainless steel tubes to form the shape of a circle or "compass" (one block at north, east, south, and west points). The sculpture includes Wausau Ruby Red, Glacial Rose, Amberg Silver