Description

This instrument consists of a glass thermometer nestled in a wooden case. The thermometer is secured within the case by two metal straps. The top strap is removable so the thermometer can be removed from the case. There is a bulb with mercury at the bottom of the instrument, and temperature measurements are marked along the glass tube. The wooden case is filled with lead shot.

In the 1870s, scientists began to investigate the properties of the ocean floor. One that remained elusive, however, was its temperature. Though recording thermometers did exist, they only measured minimum and maximum temperatures— there was no way to know the temperature at a particular spot. These devices were also inaccurate, and any jostling would erase their measurements. In 1874, Henry Negretti and Joseph Zambra developed a new type of thermometer with a protected bulb of mercury in a novel casing that both allowed the user to fix the temperature at will and could withstand rough handling.

This thermometer was used by MIT chemistry professor William Ripley Nichols in his work on the oxygen content of sea water on the New England coast circa 1873-1876.