A limestone found in seams of great thickness in non-crystalline texture with earthy appearance, is called

The percentage of silica in a good brick clay should vary from

The hapd hardening Portland cement is obtained by

The bricks after moulding should be dried in

Gun cotton is made by saturating cotton with nitric acid.

Distemper is used on

The indentation marks left on bricks during the process of moulding, are known as

The compressive strength of paving bricks should not be less than

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