One of the major problems of first fluids used for lighting fires(such as those used in flamethrowers) was that they splashed and drained too easily. The U.S. found that flamethrowers that use a gasoline gel are able to shoot farther and are more useful. Gasoline gel was hard to make in large numbers because it used natural rubber, which was in high demand and expensive. However, napalm provided a much cheaper choice. It solved the problems involved with rubber-based incendiaries(things made to cause fire).