The oscillations are controlled either by a key inserted in the primary circuit of the exciting induction coil or transformer, or by a key cutting in and out of the primary condensers or throwing inductance in and out of the closed oscillation circuit.
An interesting case of embankment and cutting in combination was involved in crossing Chat Moss on the Liverpool & Manchester railway.
The west boundary of Achradina is marked farther south by a perpendicular cutting in the rock, on the top of which a wall must have run (see above).
The main road from Durham to Sunderland here passes through a remarkable cutting in the limestone 80 ft.
Another use of colored glass was for cutting in the shapes of hieroglyphs for inlaying in wooden.
