Talk:Connaught Tunnel

Wording
It had a grade of only 0.95 per cent westward, and was tangent; light at one end can be seen at the other ...

What does "tangent" mean in this context? And why the past tense? CaGlwwWEDymzc7KBQC8u (talk) 16:47, 20 July 2017 (UTC)