This paper examines the parallels in the development of the watch and the wearable computer. It discusses how the locations where the watch was worn on the body has changed over time, examines a variety of user interfaces for watches, and looks at how the watch affected cultural concepts of time and time discipline. The watch long ago encountered many of the major issues confronting wearable computing today. The lessons for wearable computing are that the physical wearability will be determined as much by fashion as by human anatomy, that the user interface will gradually become simplified as people become more acquainted with computers, and finally that the cultural impact will be a broadening of the definition of information, a rationalization of representing information, and