A friend sent this along knowing I’d love it.

"In 1951, A.C. Gilbert, inventor of the ERECTOR set, released the U-238 Atomic Energy Lab. Using real radioactive materials, one could witness mist trails created by particles of ionizing radiation.

The set included four Uranium-bearing ore samples, and originally sold for $49.50, and one could order replacement radioactive materials. 

Note: Geiger Counter sold separately.”