Write an article based on this "Find a clear, cylindrical container. Make a container. Weigh your gauge down with pebbles. Inscribe a scale upon your container. Place it under the open sky, on level ground."
This cylinder can be either glass or plastic, and should be at least 12 inches tall. The shape is important: if the top is wider than the bottom (or narrower) it will require much more calculation and measurement. It doesn't actually matter how wide container is, so long as it's the same diameter all the way through. As the volume of the container gets biggerfrom say, a coke can to a mop bucketso does the area which collects the rain. Because of this, one inch of rainfall will be recorded consistently between cylinders of varying sizes. If you don't have a cylinder on hand, you can make an equally effective gauge with an empty 2-liter soda bottle and little work. Using scissors or a knife, cut the top 4 inches of the bottle off. Don't worry about the uneven bottom of the bottle. That will be taken care of in the next step. Because rain will often be accompanied by wind, you'll want to steady your gauge so that it can stay upright through a storm. Fill the bottom with pebbles or marbles, but don't go higher than an inch or so. Once that's been done, you'll want to fill your container with water, to provide a level starting point for your scale. Your weights will be taking up volume, and so we don't want them included in the measurable area. Rocks, stones, marbles: any small, relatively heavy objects will do, as long as it won't absorb any of the water. If you've created your own gauge with a soda bottle, make sure the entire bottom (the four separated points of the base) is filled with water and stones, to provide a flat starting point for your scale. As an alternative to placing pebbles in your gauge, you could place it within a sturdy container, such as a heavy bucket or flowerpot. This can be done with a waterproof sharpie. Hold a ruler or measuring tape up against your bottle, and line its zero up with the current water level of your gauge. Your scale's zero should also be at this water level. If you've opted to go pebble-free and are going to place your rain gauge inside a flower pot, you won't have any water in your gauge yet. In this case, zero will be at the bottom of your container. You need level ground to lessen the chance of your gauge tipping over. Ensure your gauge has no obstructions above it, e..g trees or eaves, as these will disrupt your measurements.