PUBLIC HEALTH ENGLAND / SCIENCE PHOTO LIBRARY PUBLIC HEALTH ENGLAND / SCIENCE PHOTO LIBRARY
Thermometer being used in a laboratory. The bulb of the thermometer is at lower left. This thermometer contains mercury, and is about to be used to measure the temperature of the red chemical in the beaker. The volume of the mercury increases with an increase in temperature, sending the mercury rising from the reservoir in the bulb up a narrow column inside the thermometer. The graduated scale on the thermometer allows the final level of the mercury to be recorded as the temperature of the liquid.
Model release not required. Property release not required.