The time required for seasoning of timber in kilm seasoning is

The bulking of sand

The addition of pozzolana to Portland cement causes

Gun cotton is made by saturating cotton with nitric acid.

The central part of a tree is called

The shrinkage of ordinary concrete is about

The constituent in lime which retard the slaking action and increase the rapidity of setting, is

Gneiss is chemically classified as

The frog of a brick is normally made on its