OUR WINTERS of hard use around International Falls, Minn., and also in neighboring Canada have proved the Merrymaker snowmobile to be a practical, rugged vehicle ideal for cold climates. The thrust of a propeller driven by a Continental aircraft engine drives the vehicle over snow and ice and, when it is necessary to transport the snowmobile over dry highways, it becomes a “self-contained” trailer. In about 15 minutes two men can remove the three runners, install two wheels and the unit hooks to a trailer hitch on a car for a quick change of locations at highway speeds. The easy transition from snowmobile to the trailer was made possible on the original because it is built on a modified boat-trailer frame. Although it is possible to build the snowmobile from the ground up by using the dimensions and drawings in this article, the modified trailer, which includes the steering mechanism and adjustable clamps for holding the mount of the aircraft motor is available from the Otto P. Miller Trailer Co., Almena, Wis. Use of the modified trailer will considerably simplify construction and save time.