Waywiser, is the online database of the Collection of Historical Scientific Instruments, Harvard University. It was first developed by Jean-François Gauvin and Sara J. Schechner in 2007--2008, and has since been updated in format by Juan Andres Leon and other museum staff. As curator of the Collection, Schechner is the contributor of thousands of object entries and biographies, particularly in the areas of astronomy, microscopy, optics, time finding, horology, surveying, navigation, psychology, and radio. Work on the database is ongoing. The database is named after an ancient instrument for measuring distance, also called a hodometer.