Mohammed's Ladder
"Mohammed's Ladder", "Kirk Narduban", or the "Ladder of the Prophet" pattern from a Kurdish dagger. 'Rungs' of the ladder are alterations in the background pattern running perpendicular to the length of the blade. 'From Art To Science Seventy-Two Objects Illustrating the Nature of Discovery' by Cyril Stanley Smith. "Both the beauty and the serviceability of fabled Damascus steel arise from its inherent structure. Unlike European steel prior to the mid eighteenth century, it was of very high carbon content and had been melted. The pattern originated in a coarse crystalline segregation of iron carbide, preserved in lamellar form by extremely careful forging at low temperature. The pattern (often called water from its resemblance to ripples on a pond) only becomes visible after etching, which differentiates the high- and low- carbon areas. This sword has a particularly fine texture. It shows the once-mysterious pattern of cross-markings known as Mohammeds Ladder, which was produced by filing transverse grooves in the surface of the blade just before it was forged to it final shape."
