History of the anchor the early 2000s took elements of the Spade and other types, and developed unique solutions of his own, in order to design the "Rocna" anchor, a general purpose type which uses a concave fluke, a self-righting roll-bar, and setting skids. History of the anchor The History of the anchor dates back millennia. The most ancient anchors were probably rocks and many rock anchors have been found dating from at least the Bronze Age. Many modern moorings still rely on a large rock as the primary element of their design. However, using pure mass to resist the forces of a storm
Morphism of algebraic varieties Morphism of algebraic varieties In algebraic geometry, a morphism between algebraic varieties is a function between the varieties that is given locally by polynomials. It is also called a regular map. A morphism from an algebraic variety to the affine line is also called a regular function. A regular map whose inverse is also regular is called biregular, and they are isomorphisms in the category of algebraic varieties. Because regular and biregular are very restrictive conditions – there are no non-constant regular functions on projective varieties – the weaker condition of a rational map and birational maps are frequently used