For measuring speed of a motor? A speedometer (speed-meter) For measuring the distance a bicycle travels? A cyclometer (cycle-meter). In each case what does "meter" mean? It means an instrument for measuring. What name may I give to an instrument for measuring heat? You may call it a heat-meter. Tell the pupils that, in science, many Greek words are used, and that you will put a Greek word in place of the English word "heat", namely "thermos", as in thermos bottle. What will the name become? Thermosmeter, or _thermometer_. 3. Practice in using thermometers: The unit of measurement (_degree_) should be given, and the scale taught from the black-board. Thermometers may then be given to the class to examine and use. Saucepans having white inner surfaces are best to use for the experiments, as changes made by the heat are more plainly seen. _Observations of water under heat:_ (1) At a temperature of about 100 degrees, very small bubbles form at the bottom and sides of the dish and rise slowly to the surface of the water. These bubbles are a film of water containing the air that was in solution, which, when expanded, rises to the top of the water. (2) At a temperature of about 180 degrees, a few larger bubbles form at the bottom of the dish and rise slowly to the surface of the water, making a slight movement in it. In these bubbles air is replaced by steam which is formed from the water by the heat. (3) At a temperature of 212 degrees, a great number of large bubbles form and rise quickly to the surface, making much movement in the water. The water is then said to boil. (4) The water will take no higher temperature than 212 degrees. (5) After water once boils, it requires little heat to keep it at this point, therefore the heat may be reduced. (6) An increase of heat increases the number, size, and rate of the bubbles and the volume of steam, but makes the liquid no hotter. _Application of these observations:_ (1) If food be cooked in a liquid at its greatest heat, where many bubbles are making much movement in it, the process is called _boiling_. (2) If cooked in a liquid heated to 180-200, where there is scarcely any movement in the liquid, the process is called _simmering_. (3) If cooked in the steam rising from a boiling liquid, the process is called _steaming_. (4) If boiling liquid be poured over food and no further heat applied, the process is called _steeping_. LESSONS II, III, IV, ETC.