THERMOMETER
(QURATULAIN ZIKRUR REHMAN, karachi)
A thermometer is a device that
measures the temperature of things. The name is made of two smaller words:
Thermo means heat and meter means to measure.
Once of the earliest inventors of a thermometer was probebly Galileo. We know
him more for his studies about the solar system and his "revolutionary" theory
(back then) that the earth and planets related around the sun. Galileo is said
to have used a device called a "thermo scope" around 1600- that's 400 years ago!
When you are sick ,your mother takes your temperature with a glass thermometer
containing a silvery liquid called mercury . This type of thermometer, the
mercury-in -glass type, is made in four parts: a sealed glass tube, a glass bulb
at the bottom (the part you put in your in your mouth) ,a scale of measurements
,and a liquid, such as mercury.
Mercury is an ideal filler in a thermometer, for heat causes it to expand and
cold causes it to contract. When your temperature is taken and you do have a
fever, the mercury responds to that body heat by increasing in volume. Within
minutes' there is too much mercury for the small bulb to hold, and the mercury
rises in the tube. When the mercury is heated to the same temperature as your
body's, it stops rising along the tube. The numbered point on the scale of
measurements tells your temperature.
can you imagine..........
Even though the average body temperature of an adult is 98.6 degree F., in some
diseases and in sunstroke, body temperatures have reached as high as 115 degree
F.!