| http://www.w3.org/ns/prov#value | - July 10, 1866 - Edson P. Clark, of Northampton, MA, received a patent for an Improved Indelible Pencil (Improvement in Pencils for Producing Indelible Writing on Linen and Other Fabrics...consists in the employment of gypsum and black lead incorporated together...in connection with nitrate of silver to be made into pencil-leads which are inclosed in wood or other material).
|
