User:Sam.roebuck/Limestone Corner

Limestone Corner is an area of Hadrian's Wall (and assosiated defenses) at its most northerly point. It therefore also represents the most northerly point of the Roman Empire, outside the two periods during whech the Antonine Wall was occupied by the Roman military. Other notable features at Limestone Corner are the wall ditch at this point, which was never completely excavated, a Roman camp, and the site of Milecastle 30. Also present is a trig point.

Geology
Despite the name, the rock in the area is not actually limestone, but a quartz-dolerite whinstone.



Wall ditch
The wall ditch at this point was not completed when first cut. At a point due north of the trig point, only a small amount of topsoil has been removed. A few metres west of this point, significant whinstone blocks remain in the ditch, with others deposited on its northern lip. One large rock provides clues to the methods used by the Legionary enginners to cut the rock. Holes have been drilled (or cut) into a vein of quartz on the rock's upper surface. Wedges could then be hammared into the holes to allow the rocks to cleave along the weakness provided by the quartz vein. Two iron wedges were discovered within the wall core at Milecastle 26, consisting of steel-faced tips, and soft heads for hammering. It has also been suggested that wooden wedges can be used. Having been driven into the hole, water could be poured onto the wedges, causing expansion.

No conclusive reason has emerged as to the incomplete nature of the wall ditch at this point. It is often suposed that the rock became too hard at this point, though the vallum was cut (presumably at a later date) through the same stone.

Vallum
The vallum at this point is relatively complete. The vallum ditch has been succesfully cut through the same rock as that through which the wall ditch passes. Secondary crossings are apparent at 41 m intervals, though many are incomplete. The marginal mound is apparent in this area, containing large quantities of whinstone, as do both mounds. There are occaisional large whinstone rocks present on the north and south berms, having been cut from the vallum ditch and deposited whole.

Milecastle 30
Limestone Corner also marks the site of Milecastle 30.



Roman camp
The reamins of a Roman camp (also referred to as Limestone Corner) are located at the highest point of the hill on which Limestone Corner is situated. This is 150 m due south of the bend on the B6318 Military Road. It square, measuring around 50 m on each side, and enclosing an area of around 0.2 ha. Although a farmstead (now consisting only of a series of banks) was later built within the camp, the rampart, ditch, gateway and traverses remain visible.

The camp was excavated in 1912. Pottery dating to the second century was found, along with pottery dating to the late third or early fourth century.

Location: 55.03832°N, -2.1927°W



Trig Point
The Trig Point at Limestone Corner is of the Pillar type. It has identification number TP4416, and is known as Limestone Bank. Limestone Bank trig pillar was one of the 2173 triangulation pillars that constituted what was known as the Secondary Network. These pillars filled in gaps between the Primary Stations, erected during the Retriangulation of Great Britain. It is no longer in use.

The associated Flush Bracket has identification number S6659. Flush brackets were fixed to walls at 1 mile intervals between Fundamental Benchmarks, and also on trig pillars. They consist of a metal plate with a unique number. There is also a horizontal mark with three vertical marks pointing towards it from below (the same mark as was carved into walls for lower order benchmarks).

Location: 55.03832°N, -2.1927°W