General view of a melt viscometer used during the early stages of nylon production and research at the DuPont Experimental Station in Wilmington, Delaware. This machine was used to measure the melt viscosity and molecular weights of experimental polymers as a means of evaluating the consistency of these materials. Notably, the name of Dr. Paul Flory, winner of the 1974 Nobel Prize for Chemistry, is imprinted on the nitrogen cylinder visible on the left-hand side of the photograph, indicating that the nitrogen met his standards for purity. To protect hot nylon polymers from oxidation, DuPont notably used a purified grade of nitrogen that became known as "Seaford-grade nitrogen" after the company's nylon plant located in Seaford, Delaware.