A: Bulb containing mercury attached to a glass tube of narrow diameter. Thermometer has Celsius scale with 0-100 degree range.
B: Protective cardboard tube for the thermometer (not digitized).
Partial immersion thermometers are designed to indicate the actual temperature when a specified portion of its stem is exposed to the temperature being measured. The immersion line is a quick and easy visual indication to the user. The thermometer should be immersed to the line for correct temperature indication, though some partial immersion thermometers do not have an immersion line inscribed; for example, thermometers with standard taper joints, or thermometers with very short immersions, such as for melting point applications.