Brattice

A practice then prevailed of blasting without nicking the side of the place which still continues and of conducting the current of air too far by means of brattice, to both of which practices I raised a strong objection. They admitted their inability to make the men nick the coal as they formerly did and thought the application of brattice could not be properly defined, but that it should be left to the discretion of the manager of each particular mine as to the distance openings should be made apart between the intake and return air courses.

[…] When a breach was made in the castle wall, a brattice could be built within to serve as a new temporary defence.