Such part of the London Extension of the former Great Central Railway in the County of Leicestershire as comprises so much of the Railway (No 1) described in and authorised by the Manchester, Sheffield and Lincolnshire Railway (Extension to London &c.) Act 189310 (as altered in level pursuant to Section 4 of the Manchester, Sheffield and Lincolnshire Railway Act 189411 and widened pursuant to Section 5 of the London and North Eastern Railway Act 193812) as extends in a southerly direction from the boundary between the Borough of Charnwood and the City of Leicester at the former Belgrave and Birstall Station to a point 261 metres from that boundary.