1898.] Professor L. C. Mlall, on a YorJcshire Moor. 621 



WEEKLY EVENING MEETING, 



Friday, February 18, 1898. 



Basil Woodd Smith, Esq. F.E.A.S. F.S.A. Vice-President, 

 in the Chair. 



Frofessor L. C. Miall, F.R.S. 



A YorJcsliire Moor. 



The Yorkshire moor is high, ill-draiued, peaty, aud overgrown with 

 heather. Moors of this type abound in ScotLand, and creep southward 

 along the hills into Yorkshire and Derbyshire, breaking up into 

 smaller patches as the elevation declines. In the south of England 

 they become rarer, though famous examples occur in Dartmoor and 

 Exmoor. In the north they may cover great stretches of country. 

 It used to be said that a man might walk from Ilkley to Glasgow 

 without ever leaving the heather. That was never quite true, but 

 even to-day it is not far from the truth ; a man might walk nearly 

 all the way on unenclosed ground, mostly moorland. 



Neither peat nor heather is confined to high ground. Peat often 

 forms at sea level, and may contain the remains of sea-weed. In- 

 some places it is actually submerged by change of sea level, and the 

 peasants go at low water and dig through the sand to get it. Heather 

 ranges from sea level to Alpine heights. 



Peat may form because there is no fall to carry off the w'ater, or 

 because the soil, though high and sloping, is impermeable to water. 

 A few feet of stiff boulder clay constitute such an impermeable floor, 

 and a great part of our Yorkshire moors rests uj^ou boulder clay, 

 which is attributed to ice action, because it is often packed with ice- 

 scratched pebbles, some of which have travelled far, and because the 

 rock beneath, when bared, exhibits similar scratches. 



The rocks beneatli tlie boulder clay of a Yorkshire moor are 

 chiefly sandstones and shales. Where the sandstones crop out, they 

 form tolerably bold escarpments with many fallen blocks, such as we 

 call " edges " in the north ; the shales make gentler slopes. Both 

 the surface water and the sjjring water of the moors are pure and 

 soft ; they may be tinged with peat, but they contain hardly any lime, 

 j)otash or other mineral substance except iron oxides. 



The Avettest parts of the moor are called mosses (in some parts of 

 Scotland they aro called flow-mosses) because the S2>hagnuui moss 

 grows there in profusion. The Sphagnum swamps are an important 

 feature of the moor, if only because they form a great part of the 

 peat. Not all the peat, however; some is entirely composed of 

 heather and heath-like plants, while now and then the hair moss 

 (Polytrichum) and certain moorland lichens contribute their share, 



