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Thermometer - MSN Encarta |
 | | The modern alcohol and mercury thermometers were invented by the German physicist Gabriel Fahrenheit, who also proposed the first widely adopted temperature scale, named after him, in which 32° F is the freezing point of water and 212° F is its boiling point at standard atmospheric pressure. |
 | | A mercury-in-glass clinical thermometer, for example, is a maximum-reading instrument in which a trap in the capillary tube between the bulb and the bottom of the capillary permits the mercury to expand with increasing temperature, but prevents it from flowing back unless it is forced back by vigorous shaking. |
 | | In measuring the air temperature outside a building, for example, if one thermometer is placed in the shade and one in the sun, only a few centimeters away, the readings on the two instruments may be quite different, although the air temperature is the same. |
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