A horizontal shaft driven to the mine workings from the surface, for drainage and transport purposes. Usually the trucks are counterbalanced by a small but very heavy truck which will pass underneath the slate truck. There is also usually a drum with a brake at the top of the incline.
Some inclines are water powered instead.
Level A flat area at a constant height throughout the mine, usually with a tramway network on it. They are numbered from 1 at the highest level of the mine in ascending order to the lowest point of the mine. Pitch A caving term meaning a vertical drop. This is a method used to ascend a single hanging rope. Generally you start at the top of a mine, abseil into it, and then use SRT to get back out again.