Thank you Kirk. I added the images here
http://www.picturetrail.com/sfx/album/view/20091342
From the July 24, 1886 "Scientific American" article on Parker Bros. courtesy of Jeff Kuss
(The illustration)...shows the manner in which the metal is worked up to form the gun barrel, to make the Damascus twist. Alternate rods of iron and steel are placed upon one another, and then forged and thoroughly welded together into a solid bar, which is afterward rolled into rods. The rod thus formed is raised to a bright red heat, and on end placed in a revolving chuck, while the other remains fixed, the turning of the chuck subjecting the rod to a severe twisting throughout its whole length, so that at last it acquires the appearance of a screw having a very fine thread. Three of these rods are then placed together, the twist of one being in a contrary direction to that of the other two, and they are welded together and rolled, making the strip which is wound around the mandrel...the coil being welded till the spiral unite to form a hollow cylinder.
The fine figures that appear in the finished barrel are the result of the skillfulness with which these several operations are performed, after which follows a process of hammering while the barrel is nearly cold, to further condense the metal, and the barrel is then ready to be bored, turned, and finished. About three-fourths of the material is cut away in the making, 16 pounds of iron being used in the first instance to make a pair of barrels which would weigh only 8 pounds when the welding is finished, and from three to four pounds after boring and grinding.
In the manufacture of laminated steel barrels, the best quality of steel scrap is mixed with a small proportion of charcoal iron, heated in a furnace, puddle into a ball, well worked up under a forge hammer, drawn out under a tilt hammer into strips of the required length and thickness, and then treated as above described. Such barrels are much esteemed for hardness and closeness of grain, and show a different marking and appearance from those made by the Damascus twist.
It is only by such elaborate treatment of the metal that gun makers have succeeded in making guns so very light, and yet of such great strength and beauty.