Blog Posts by Subject: Manufacturing

On quitting his classes at Harvard in 1927, Edwin Land moved to New York and became a regular user of the library’s Science Division. His goal: the manufacture of a polarizing light filter, the basic idea behind Polaroid sunglasses. Between the library and a variety of makeshift labs, he eventually figured out how to embed microscopic crystals of “herapathite” in molten sheets of plastic and align them all in one direction. He named the invention Polaroid, and used the name again when he invented his instant photography. Land had discovered the identity of the crucial polarizing crystal while reading an 1852 article by the British doctor-scientist William Herapath,