The Gilbert U-238 Atomic Energy Lab is a toy lab set that was produced by Alfred Carlton Gilbert, who was an American athlete, magician, toy-maker, business man and inventor of the well-known Erector Set. The U-238 Atomic Energy Lab was released by the A.C. Gilbert Company in 1950. This lab's intention was to allow children to create and watch chemical reactions using radioactive material.The lab contained a cloud chamber that allowed the viewer to watch alpha particles travel at 12,000 miles per second, a spinthariscope that showed the results of radioactive disintegration on a fluorescent screen and an electroscope that measured the radioactivity of different substances that were in the set. This toy is looked upon as being dangerous because of the radioactive material in the set, but Gilbert claims that none of the materials could conceivably prove dangerous. Unlike Gilbert's other chemistry sets that his company released, the U-238 Energy Lab never gained popularity and the toy was taken off shelves only a year later, selling only from 1950 and 1951. Even over 35 years after its release, children still preferred the Erector Set.