Instrument to you the secrets of Galileo balls as well

It is said that the first thermometer is the stained glass bulb thermometer, in 1593 by the Italian scientist Galileo ( 1564 ~ 1642) The invention. Now in the market, also known as Galileo thermometer, it is mainly used for interior decoration or for gift collection, etc. The thermometer in the glass ball has a wonderful features, if the current room temperature exceeds the glass ball bottom tags shown in temperature, then the glass ball will sink, on the other hand will rise. Therefore, the lower the temperature float balls, the more the more balls at the higher temperature sink. Galileo thermometer readings although there is no professional precision thermometer, but did have fun. Careful observation will find that small glass ball up and down in the tube arrangement is regular, the highest temperature drop ball at the top, the lowest in the bottom, and whether or not the ball, or sink or float, both from the top down according to drop temperature descending order. When all balls are still in the glass tube, not up and down, all the floating ball in the bottom of a small ball drop temperature is measured by the current temperature. The thermometer is different, and use this kind of thermometer is the density difference principle. In short, under a certain temperature, small glass ball's overall density is greater than the transparent liquid density in the tube, it is the buoyancy of transparent liquid is less than its gravity, ball sinking; On the other hand, if the overall density of small glass ball less than transparent liquid density in the tube, it is the buoyancy of transparent liquid is greater than its gravity, small ball float. When the transparent liquid in the tube temperature change, its density will change. So different ball float or sink to a equal position with the surrounding liquid density. If the overall density of control the ball, make the lowest ball row overall density from above, the highest row at the bottom, thus forming temperature scale, used to indicate the temperature. Temperature is generally read from a markings lived in each glass balls on the metal disk. Said there is also a manufacturer, under the glass ball that seemingly metallic card is plastic, because of the commonly used heavy metal material will make the overall density is too large to float glass ball. And, in fact, almost no difference between glass ball, is precisely control the drop weight in a glass ball overall density role.