Meanings of vitrify brick in English

To get the total cost of the sewer proper we must add the cost of the vitrified brick invert paving.

Vitrified bricks, made from clay or ground shale, are burned until the materials begin to fuse superficially, forming their own glaze.

The finished products were as follows: Open-hearth steel rails, bar and angle iron, car wheels, bar steel, steel plate, sewer pipe, and vitrified brick.