Page:Popular Science Monthly Volume 88.djvu/936

 Ice Skatine in Summer Without Ice

��ICE can be made artificially for summer skating. It has the disadvantage of melting. For that reason, chemists have devised glassy surfaces which will stand heat and which will be as accept- able as ice in winter.

Some years ago a German patented a process, in which thick pasteboard plates are immersed in very hot linseed oil and varnish, mixed with glue. After becoming thoroughly permeated with this mixture, they are subjected to a powerful pressure, which squeezes out the excess of oil and gives them great strength. When dry, the plates are immersed in hot paraffin and again put under pressure. To one side of each plate a layer of parchment is applied; the other side is coated with gypsum and tar. The plates, with the parchment sides up, are then fitted together on the

��floor and united by cement. The finished surface of the rink is coated with a material consisting of one part of glycerin, two parts of wax, and three parts of oil. An unusually smooth floor is thus formed ; but ordinary skates cannot be used, since their sharp edges would soon cut up the surface beyond repair.

Another compound contains soluble glass, fluor-calcium, asbestos, ground glass or flint, paraffin and soapstone. These substances, when thoroughly mixed, are applied to the floor. A thin coating of soluble glass and a layer of paraffin are then added. Absolute smoothness is obtained by passing a heated roller over the surface. If the surface becomes scratched, more heat is applied, or fresh coats of glass and paraffin are added.

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��Diagrams showing treat-nent of floors. The hot salts are poured into frames on the floor. After solidifying, the frame is removed and used for the next section. The frame with the galvanized-iron wire nets is used in re-surfacing the floor, a rubber bag filled with steam being laid on it. The heat is thus applied without bringing the bag into direct contact

with the salts

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