but it is hoped that you will approach this thinking like an astronomer and gaining an appreciate for not just a high-quality sundial's amazing craftsmanship, but also the science that has allowed this class of devices to perform their single, endless job for thousands of years...
During the height of the sand glass, doctors, apothecaries, and other medical practitioners carried miniature or pocket sand glasses with durations of one-half or one minute to use when timing pulses; the practice of carrying these continued until the nineteenth century. Today, miniature versions ...