BT Scientific & Educational Abbreviation

Bathythermograph

A device developed by Athelstan Spilhaus in 1938 to measure temperature/depth profiles in the ocean, the bathythermograph was basically a reworking of a mostly unworkable device called an oceanograph built in 1934 by Carl–Gustav Ross by for the same purpose. It consisted of an open, rectangular frame in which a compressible bellows with a pen arm and stylus was mounted at one end. The stylus rested on a smoked glass slide and moved across it to scratch a record of ocean temperatures. The stylus also moved vertically with changes in depth and thus created a temperature/depthprofile. The bathythermograph (or BT) was further improved by Maurice Ewing and Allyn Vine in 1940.