CAN WATER BE SUPERHEATED?

Auckland Star, Volume LXVI, Issue 224, 21 September 1935, Page 7 (Supplement)

CAN WATER BE SUPERHEATED?

It is a curious fact tliat although water normally boils at 212 degrees Fahrenheit (100 degrees Centigrade) it can under certain circumstances be heated to a considerably higher degree without boiling. If a vessel containing pur© water is heated very gradually and uniformly it sometimes happens that the water does not boil on reaching 212 degrees. The temperature of the water increases, but after a while a point is reached (the actual temperature depends on. several factors) at which the superheated water turns into steam explosively. Another way in which water has been super-heated is by putting drops of water in a liquid which does not mix with water and which has i exactly the same density as water but boils at a higher temperature. AS the drops of water are of the same density they remain suspended in the liquid. The liquid is heated gradually, and under favourable circumstances the drops of water will not boil when the liquid reaches 212 decrees, but, as in the previous case, continue to heat until they suddenly and explosively turn into steam. Water can, of course, be made to boil at a higher temperature than the normal by subjecting it to increased atmospheric pressure, as the boiling point of water, like that of all liquids, depends on the pressure of the air, the higher the pressure the higher being the boiling point.