There is a significant market in convenience foods for campers, such as dehydrated food products. Portable soup was a kind of dehydrated food used in the 18th and 19th centuries. The International Children's Fund shipped more than 150,000 pounds of dehydrated food in 2013. It was a precursor of meat extract and bouillon cubes, and of industrially dehydrated food. They carried 45 sand filled limpet mines and dehydrated food for three days. Hash browns are also manufactured as a dehydrated food, which is sometimes used by backpackers. This dehydrated food consists of wide noodles, assorted dried vegetables and flavouring powder.