96 LIAS OF ENGLAND AND WALES : 
the thickness, colour or uses of the bed, or from some other local 
peculiarity, as at Rugby where we find the Knotty Rock, Big 
Jumbler, Cat Heads, &c. Other local names in use at Lyme 
Regis, Street, &c., have been already noted. 
Dew Stone. The term Dew or Jew Stone is most likely 
derived from the Celtic Dhu or Dubh, meaning black. Thus the 
Glee Hill basalt is known as Dhu stone, and it is quite likely that 
the name has been used by quarrymen for dark-coloured rocks in 
various parts of the country ; but it has to a great extent lost its 
original meaning, as the " Dew stone " in many places is a brown 
or buff limestone, 
Bastard Lias. An inferior or decomposed stone. 
Burrs. A term (meaning rough) that has been applied to Blue lias stone, used 
for building ; at Axminster (Buckland, Trans. Geol. Soc., ser. 2, vol. i. 
p. 99) ; and to other rocks, in the Purbeck strata, &c. 
Clog (derived perhaps from the Celtic clog or clock, a stone) is applied to 
certain hard limestones of the Lower Lias, employed for building. 
Firestone. Applied to tough coarse-grained Lias limestones that are some- 
times used " for forming the arch -work of lime pits," Axminster (Buck- 
land, op. cit.) At Lyme Regis, some of the Firestone-nodules have been 
shaped into fire-balls. 
Pendle. Applied to shaly limestone at Wilmcote ; the name is also used 
for fissile beds in the Stonesfield Slate and Purbeck Beds. 
Sizes. Applied to layers of Blue Lias limestone, in some cases to beds that 
are useful for paving : the term usually has reference to the thickness of 
the beds. 
Road Metal. 
In former days it was usual to mend the roads, wherever 
possible, from material obtained in each parish. Consequently 
there were far more quarries in the strata than is the case now-a- 
days, when materials are brought from a distance. (See p. 12.) 
The limestones of the Lower Lias, and the Marlstone, have 
yielded much road-metal, and the stone is still employed in many 
places. 
The Lower Lias limestone is not a good material, as it grinds 
readily to powder, forming in dry weather a thick white dust, 
and in wet weather sticky mud. Sandy and ferruginous limestones 
met with in Leicestershire and Lincolnshire have also been used 
for road-metal. 
The Marlstone in many places furnishes a more durable 
material, especially in the neighbourhood of Yeovil and Ilminster, 
in Somerset. There the Rock-bed, sometimes little more than a 
foot in thickness, is much in demand : for it is a tough and 
durable stone. Near Dursley, in Gloucestershire, and in the 
Midland counties, the Marlstone (both ironstone, and earthy 
limestone) is also used, but chiefly now-a-days for mending the 
by-roads. 
Bands of calcareous sandstone or of shelly limestone in the 
lower part of the Middle Lias have also been used for road- 
metal. These lower beds have thus been worked at Overthorpe, 
near Warkworth, and at Twyford lane, near Adderbury. 
