I've been working through weaving some leno structures from a book published in 1908. The book is in French, and doesn't have much explanation for the diagrams, so this is my interpretation of the weaves. The ones pictured here all have two ground (stationary) warp ends for every doup warp end (the end that crosses under the grounds and back). They are 10/2 cotton set at 18 epi. Some extraordinary variety is possible on just one or two threadings!