Smithsonian - National Museum of American History, Behring Center

Physical Sciences Collection - Navigation

Browse Makers | Browse Instruments | Index

Browse by Instrument

Aircraft Sextant
Azimuth Instrument
Box Sextant
Gunter Quadrant
Reflecting Circle
Star Finder



The magnetic compass originated in China and was in use in Europe by the twelfth century. By the sixteenth century, instrument makers were equipping compasses with gimbal mounts so that they would remain horizontal even though the ship might be unsteady. Also, having recognized the problem of magnetic variation (that is, the position of a magnetic needle varies from place to place), they made azimuth compasses that could be aligned with true north.

Simple marine compasses have a magnetized needle attached to the bottom of a paper card, and are inherently unstable. Since the 1850s, scientists and instrument makers have struggled to solve this problem. One solution, pioneered by E. S. Ritchie in the United States, was to float the magnetic needle in a bowl of liquid. Another solution, this one pioneered by William Thomson in Scotland, was to build stabilizing elements into dry card compasses.

Ref: "Magnetic Compass" in Robert Bud and Deborah Warner, eds., Instruments of Science. An Historical Encyclopedia (New York & London, 1998), pp. 134-136.


Ball Dry Card Compass
Bamberg Liquid Compass
Blunt Dry Card Compass
Burrough Dry Card Compass
Dry Card Compass (unmarked)
Hellfricht; Breed Dry Card Compass
Hughes Liquid Compass
Japanese Compass
Jorges Dry Card Compass
King; Thaxter Dry Card Compass
Kjersgaard Dry Card Compass
Legris Compass
Marine Compass Co. Dry Card Compass
Merrill Dry Card Azimuth Compass
Morton; Kelvin, Bottomley & Baird Dry Card Compass
Riggs; Helffricht Dry Card Compass
Ritchie Liquid Compass (#10601)
Ritchie Liquid Compass (#23924)
Ritchie Liquid Compass (#6937)
Ritchie Liquid Compass (#9786)
Ritchie Liquid Compass (patent model)
Rupp Dry Card Compass
Shaw Dry Card Compass
Sherman Dry Card Compass
St. John Dry Card Compass
Thaxter & Son Dry Card Compass
Thaxter Dry Card Compass
Thaxter Tell-Tale Compass
Thomson / White Dry Card Compass
Thomson Dry Card Compass with Binnacle
Ware Solar Compass
Witteveen Tell-Tale Compass