Nuclear magnetic resonance (NMR) equipment at US National Bureau of Standards (now National Institute of Standards and Technology), Arlington, VA in 1957. It consists of a large electromagnet "(background)", vacuum tube RF oscillator and chart recorders. It was used for solid state research. Caption: "Nuclear magnetic resonance offers a tool for the investigation of the solid state. A study of the absorption of energy of atomic nuclei in solids provides a better understanding of the local electric and magnetic fields that the nuclei experience."