The tides! Such a unique thing, because on Earth, we don’t just have oceans full of liquid water—we also have a big ol’ moon called Moon to pull them around. You might like to keep track of the tides; ...

The U.S. Coast and Geodetic Survey (NOAA’s predecessor agency) used this style of automatic tide gauge to record water levels until the 1960s. The roll of paper turned at a steady rate by the timer ...