Millbank bag

A millbank bag is like a special kind of filter that can help clean dirty water. Imagine pouring mud or dirty water into a bag made of special fabric. The bag holds the dirt and lets the clean water pass through. It's like putting a strainer into your spaghetti pot to catch the big chunks of tomato, but instead of catching the tomato, the millbank bag catches all the yucky stuff you don't want to drink or use. So when you pour the water that passed through the bag, it's much cleaner and safer to use. It's a really useful tool for people who need to get clean water in places where it might not be easy to find, like when you go camping or hiking.