The document discusses how to make a simple homemade thermometer using common materials. It explains that a thermometer measures temperature and the most common type uses mercury. The materials needed are a plasticine, glass bottle, alcohol, colored water, pipette, glass marker, and thermometer. The steps include mixing the alcohol and dye, pouring it in the bottle, sealing it with plasticine, and inserting a glass pipette and thermometer. It can then be used to measure temperature and some limitations of this simple thermometer are discussed.