Why does the bulb of a thermometer have the thinnest glass?
In a regular glass bulb thermometer, the long glass tube, or capillary, marked out with the temperature measurements is constructed of thicker glass than the small bulb at the bottom. To understand why, it’s first necessary to understand the precise workings of a thermometer.ContentsBulb thermometers contain some kind of liquid–often alcohol (dyed to make it easier to see) or the metallic silver-colored mercury.PropertiesLiquids like alcohol and mercury expand when heated and contract when cooled. Within the confines of the thermometer, the only place an expanding liquid has to go is up; therefore, heating the thermometer’s contents causes the thin line of liquid to rise, and cooling it causes the line to drop again.The BulbThe bulb at the thermometer’s base allows the thermometer to hold enough liquid so that very small temperature changes will be visible in the small space of the thermometer’s capillary.Bulb GlassThe bulb is made of much thinner glass than the rest of the thermomete
