Possibly
Damas Moucheté De La Cononnerie Ou Fabrication des Canons de FusilBy M. Ronchard-Siauve, 1864
http://books.google.com/books?id=uedDAAAAIAAJ&pg=RA1-PA202http://books.google.com/books?id=uedDAAAAIAAJ&pg=RA1-PA217Other Damas by varying the composition was made of the lopin with iron settings and of steel. Thus, by employing square settings or a square piece seen by end formed, by alternating the settings well, in manner of
derochant la trancha the section, it
represented the effect of a checkerwork, divided into black and white boxes; white boxes representing the settings of steel and black those of iron. This effect, like all the effects of Damas, is produced by the different action exerted on iron and on steel the sulphuric acid, one is useful for
dérocher; iron, struck first, becomes dull and black, while the steel remains still white and preserves its polish. The pieces are welded under the power hammer and one stretches then the rods with the rolling mill with a dimension of 3 and 4 lines or 7 to 9 mm., then one makes them undergo a rather large torsion. One twists some even cold. Torsion more or less gives a drawing more or less lengthened. It is there what the Damas Mouchete' is named.
This moucheté Damas was created in St-Etienne in 1845. Mr. Albert Bernard, canonnier of Paris, came soon to Saint-Etienne to get the means of doing it.
Albert was Leopold's brother who also made guns and barrels 1850-1872.
