 Fireworks are the simplest of solid rockets and the weakest.Evolution from fireworks brought about more complex solid-fueled rockets, which use more exotic and powerful fuels.The low-explosive properties of gunpowder, relative to the high-explosive properties of more advanced solid fuels testify to the "survival of the fittest," as the use of firework-type engines (for purposes other than entertainment or education) has virtually ceased since the late nineteenth century.