National Geographic : 1949 Nov
-V 702 Waxing Makes Sno-Cat Steering Skis Glide Smoothly over Snow and Ice Jasper Tucker removes a Cat's hickory runner from the steering yoke (upper left). After ice is scraped off with a knife (below), the ski is coated with paraffin and tar. With a blowtorch Arch Work smooths the wax (upper right). A steel keel on the ski protects against rocks and aids steering.