To measure temperatures with the thermometer
When a Celsius thermometer is graduated in a factory the stem between the two fixed points is divided into 100 equal parts by means of a special dividing engine. This is generally beyond the resources of the ordinary laboratory, but the thermometer
may still be used to measure an unknown temperature if the following procedure is adopted. The distance (y) on the stem between the upper and lower fixed points is measured and compared with the length (x) of the mercury thread above the lower fixed point
at the unknown temperature 8.
Then () = x 100 °C
Note. The Greek letter (J (theta) is the usual symbol for temperatures in °C.