The fixing of stoves of this kind entails the laying of pipes or ducts from the open to convey fresh air to the back of the stove.
Lastly, to pass over unnecessary details, the markings of various kinds to be observed on the lobes of the livers of freshly-slaughtered animals, which are due mainly to the traces left by the subsidiary hepatic ducts and hepatic veins on the liver surface, were described as "holes," "paths," "clubs" and the like.
When a number of cables follow the same route, they are generally laid in conduits made up of earthenware or cement ducts; iron pipes are used when the number of cables is small.
Manholes are placed at intervals in the line of ducts to facilitate the drawing in and jointing of the cables, and surface boxes are placed in the footways for distributing purposes.
Sometimes the amber retains the form of drops and stalactites, just as it exuded from the ducts and receptacles of the injured trees.