NOTE: Sid Lethbridge - The method, called crystalograph, used to prepare the moulds was patented in September 1879. The iron moulds were etched with acid to develop the pattern in a similar manner to depression era glassware. The technique apparently was out of style after a year or two. Dithridge and Riverside are definite possibilities for makers. Riverside was another company that used the methodology. In fact the founders of Riverside included the gentleman who held the patent.