St. Lawrence River Ice Investigation

Library and Archives Canada, Ottawa, Ontario: 35mm, VHS, 1".
"A film study of the nature and action of ice and controlling ice conditions in placing power structures. Types of ice, animation illustrates ice formation which deepens and straightens St. Lawrence River channels. The ice at Cornwall. Dr. barnes shows the newly designed mercury microthermometer and test methods. Ice observation cabin at Lock No. 2. Instruments for measuring radiation and humidity. Preparing a cut to produce an artificial ice jam at Dry Island. The use of salt, gravel, sawdust, sand and coal dust to prevent ice freezing. Wilson A. Bentley, snowflake expert, makes microscopic pictures of ice crystals. Snowflake studies at Morrisburg and window frost studies at Cornwall and Morrisburg. Ice jam at pulpwood dock, Waddington, New York. Heat mines radiate intense heat which causes ice to explode. Placing ignition wires, firing cherry and mine. Measuring area affected by the first explosion on the Waddington jam February 24, 1925. Firing first and second mines at the Chimney Island ice jam below Ogdensbury, New York, March 13, 1925. One millin tons of ice moved down the river in 9 hours and a still photograph taken on March 24, ten days later, shows the south channel entirely cleared of ice."