The cooling water in the condenser tube enters from the lower port and is discharged from the upper port, so that the air in the condenser tube can be completely discharged, and the condensed water can fill the whole condenser tube, thus achieving the best condensation effect. Up and down, water will not store and fill the condenser tube at all, and it will not condense, and it is easy to damage the instrument, so that the condenser tube will break due to local cold and heat.

When making distilled water in the laboratory, the temperature is distilled when the boiling point of water is 100 degrees Celsius, so it is not necessary to observe and control the temperature at any time with a thermometer.

That is, you just observe the phenomenon. If the water boils, it means that the temperature has reached 100 degrees Celsius, then do you still need a thermometer?