They are provided with lids, made either of lead or of wood lined with lead, which have openings to serve for the introduction of the alloy and acid, and a vent tube to lead off the vapours evolved during the operation.
Numerous small irrigation channels lead off from them, by means of which a considerable area of waste land has been brought under cultivation.
A trail of grain lead off a few feet.
From boulder strewn floor many boulder strewn floor many boulder mazes lead off including a ' z alley ' .
Sophie Taeuber's increasingly abstract collages lead off rooms showing Zurich developments.