THE NORTH YORK MOORS - A Northern Coast to Coast Walk: From St Bees to Robin Hood's Bay - page 105

The presence on Carlton Moor of a broad strip of bare ground may puzzle
for a while, especially if visibility is not good. It is the runway of a glider
station, a barren, desert-like landscape, strewn with small rocks that seem
to offer little prospect of a smooth landing. All this moorland is now Access
Land, but the airstrip is excluded.
Sandwiched between this 'runway' and the escarpment edge, the path
continues uneventfully to the summit of Carlton Moor, marked by a trig
pillar and a boundary stone.
MINING ON CARLTON MOOR
Below the moor top, and shortly to be encountered, are some old jet mine workings.
Jet in this region is synonymous with Whitby, though the history of jet mining and jet
jewellery is much more ancient, beads of the light, fossilised wood having been dis-
covered in Bronze Age burial mounds dating from 2500 to 3500 years ago. Jet was
formed about 130 million years ago, when pieces of coniferous driftwood became bur-
ied by Jurassic sea mud.
In more recent times it was a retired naval captain who introduced two Whitby men
to the art of turning on a lathe, leading to the production, around 1800 onwards, of
beads and crosses. By 1850 there were over 50 workshops in Whitby alone. Even so,
jet would never have received the prominence it did had not Queen Victoria taken to
wearing it as court mourning, following the death of Prince Albert. It was already gen-
erally recognised as an emblem of mourning, but with royal patronage a boom period
followed, and those 50 workshops quadrupled in number, eventually giving employ-
ment to over 1400 men and boys. Though the fashion ultimately declined, jet is still
carved in Whitby, and may be found by diligent searching on the beaches there.
Alum crystals, too, were a product of this remarkable region, with at least 25 quarries
active between 1600 and 1871, and nature has not quite finished her work of disguising
the massive shale heaps that litter Carlton Bank, and other places. The value of alum
lay in its property as a fixative of dyes in cloth, a secret process mastered throughout
Italy in the 16th century, and, towards the end of that century, by a member of the
Chaloner family in Britain.
Requiring 50 to 100 tons of shale to produce one ton of alum crystals, its quarrying
was a pick-and-shovel nightmare for the poorly paid labourers involved in the long, te-
dious process of extraction. Once won from the earth, the shale, piled in large mounds,
had to be burned slowly, before soaking in water. Then the solution had to be boiled,
crystallised and purified, a process that required scrub for the burning, water for soak-
ing, coal for the boiling, and seaweed and human urine for the chemistry - an altogeth-
er messy and protracted way of going about business that came to a halt in 1871, with
the closure of the Kettleness and Boulby works.