Building a snowman is a traditional method of showing off your stamina and abilities, and a way to celebrate having enough snow to do it. If you do it right, a snowman will last long after the rest of the snow has melted. If you do an outstanding job, your work could go viral on the internet. What's the best way to build one? There are thousands of YouTube videos that will tell you how, but an engineering class who published a classic how-to says that your materials are most important. In other words, you've got to start with the right snow.
Professor Roy Pruett, who was responsible for the plans, told Quartz: “The snow has to be somewhere right around 30°F (-1 °C), where there’s just a little moisture in it. It can’t be too cold or not cold enough.”
Temperature is paramount, says Pruett. Too high a temperature and the snow will be wet and lack strength. If the snow is too cold and dry, it will be too powdery to form stable snowballs, which are then built out into the base, torso, and head of the snowman. You’ll need a lot of this good quality snow: the engineers’ ideal snowman—standing 6 feet tall—takes almost 19 cubic feet of compacted snow. Proportion—the ratio of each segment to the next—is important for stability. The engineers suggest diameters of 3 feet, 2 feet, and 1 foot for the foundation, torso, and head, respectively.
There's more to it, which you can read at Quartz. -via Digg