John Wheeler: Traditionally, barometers measured air pressure in inches Today, the metric units of the bar and the millibar are the preferred units of scientists.

Lum Woodruff, a resident of Ann Arbor, Michigan, who reported weather observations to the Smithsonian Institution, patented a portable barometer that proved to be extremely popular. Its key feature ...

Gimbal-mounted mercury barometer with a rosewood case. The ivory scale extends from 26.5 to 31 inches of mercury, is read by vernier to 0.01 inch, and indicates “STORMY,” “RAIN,” “CHANGE,” and “FAIR.” ...