After three hundred years of dependance upon the broadside armed sailing man-of-war battlefleets were to change out of all recognition in the span of a single lifetime. Between 1840 and 1905, sail was replaced by steam, wooden hull construction with iron and then steel, and the shell-firing gun encouraged the adoption of armour plate. As the pace of technology accelerated, entirely new underwater weapons in the form of the mine, torpedo and the submarine evolved to theaten the traditional pre-eminence of the surface warship. 192 Pages H/B