Show Wispy Fleece Seen on Rivers Really Is Steam MILWAUKEE WIS That That Wispy fleece seen on rivers and which looks like Ilke real steam Is steam Is real steam according to a physics teacher Mothers who tell their children when asked that th what they see Is ts not steam are nil all wrong accordIng according accord accord- Ing to this teacher Theres There's an explanation for this phenomenon says lays Manfred Olson on head of the physics physic department at Milwaukee State Teachers college In fact tact there are two of 01 them them one one for Cor any body of 01 water that steams in cold weather and a special ad one for the Milwaukee river eier Its It simply because cold air cant can't hold as a. much water as warm air Olson says say So 50 the water that evaporates from the river condenser condenses con denser dense In tiny droplets on specks speck of dust dut In the air That's That the steam you see coming off oft the river Just how much water vapor can be carried In the air at certain temperatures is shown in a chart called the vapor pressure table At 32 degrees which is freezing temperature temperature temperature tem tem- water vapor pressure does not quite reach a pound per square inch Pressure Goes Up At degrees which is the boiling boilIng boiling boil boil- ing point of water the pressure goes up to l 15 pounds per square inch At zero temperature the air can hold only onty sixth one-sixth the amount of water It holds at 32 degrees When a body of oC still sUll water such as 81 a pond starts freezing heres here's what happens The top layer of water gets gels cold first But Dut as water gets geta colder it also gets heavier up to a certaIn certain certain tain point That point Is de de- grees green When the top layer of water reaches t that hat h a t temperature it sinks to bottom of the pond and the next highest layer goes to toI I the top That too reaches degrees eventually and sinks When the whole while pond reaches degrees the top layer then freezes up The top lop layer of water stays on top because water gets lighter as its temperature goes down below degrees And that's why water freezes from the top down instead of the bottom up Special Reason Now the special reason for steam on the Milwaukee river It Itis Itis Itis is the relatively hot water that pours Into the river from rom the Commerce Com Com- merce ne ne St. St St clant of nf the tho electric n company According oto to company engineers the plant takes In an average o of gallons o of water from the river every minute of the day This water is used to condense I steam in the power plant and then thenIs Is discharged back into the river through a Conduit 1 about nine ledIn feet led in diameter The used water temperature temperature temperature tem tem- is about CO EO degrees which is at least 20 degrees higher than the regular river water tempera ture m |