GENERAL VIEWS. 181 
Galliard. Very hard close grained gritstone, of which the grains 
are nearly confluent, and the mass partially translucent, is thus named : 
the term is nearly equivalent to ‘ Whin’ of the Newcastle collieries. 
The ganister or calliard of the Yorkshire coalfield is a continuous rock 
of a similar description, but the stone more frequently occurs in nodular 
masses aggregated by local molecular attraction. (Probably derived 
from Caillou Fr. a pebble). Specific gravity, Sellet bank 2'59 ; Hutton 
roof 2‘50. 
Gritstone. Composed of worn grains of quartz, adherent in various 
degrees, not distinctly laminated like flagstone, nor very closely aggrega- 
ted, like galliard. The quartz is often mixed with mica, and sometimes 
agglutinated by felspar : oxide of iron and calcareous matter are va- 
riously associated with it. There are three indistinct varieties : viz. 
Millstone grit, very coarse-grained, sometimes full of quartz pebbles 
from the size of a pea to that of a walnut. The upper millstone grit 
usually contains more felspar than the lower ones, especially toward Der- 
byshire. Freestone — an equal grained rock, often micaceous, breaking 
in all directions equally. Hazle a hard condensed gritstone, which varies 
to freestone, flagstone, and chert, according to the locality. The term is 
peculiar to the North of England. Specific gravity of millstone grit 
2-5; Freestone of Sellet bank near Kirby Lonsdale 2-30; Barnard 
Castle 2-375; Dockray moor 2'34 ; Hazle of Ingleborough 2-49; of 
Barbon beck 2-46; altered under Whin sill of Teesdale 2'64. 
Ironstone, or argillaceous carbonate of iron, occurs in the plates of 
the Yoredale series, and in the shales and plates of the millstone grit, 
but not abundantly. It is mostly in spheroidal small nodules ; but in 
Wyersdale (Bolland) it forms large septaria. Specific gravity 335, 
The rock so named in Teesdale and Aldstone moor is very different ; 
it is almost a limestone in Teesdale. 
GW.— Some of the coal of the millstone grit and limestone series 
is merely carbonaceous and bituminous plate; and even the best bed 
of it (Colsterdale, Tan hill, Leyburn,) is far inferior to that common 
