6 
tion of the fracture and form of the flake is proportionate to 
the silicious purity of the slag. ress 0 f the 
It is most convincing to observe the P jj ere t be 
formation of such flakes at Seend, near * f naces by 
iron is smelted out of the native rock 
intense heat, and the molten slag rs poured rnto ™ ^ ■ 
and tipped from the tram-waggon to the retuse n u, 
external surface of the mass is first cooled by con a 
jSSSSif SWEAT « cutting edges 
m& It i*s further satisfactory to learn from a late number of the 
+ b P Tih he says: “ After passing Jebel Duppa the rang 
ft! right^ growing higher'show a more dehmte — as 
Ser 'me^to^uJVmrend, dipping at an 
angle of 45° to the north. They consist of limestones, wtuci 
are whitish at their base and yellowish near 
With them there are bands of flint, which, bem & 1 
the rock^n which they are stratified, stand up along the 
ridges of the hills, forming low parallel walls 
Numerous angular and apparently freshly - rov J rently 
of these flints are strewn over the plain below, PP ^ 
broken by the more or less sudden expansion and contract on 
occasioned by the great variations in temperature, tim act on 
beina- probably aided by a jointed structure in the flint at the 
t'me of its removal from the limestone. That there are such 
variations in temperature may be inferred from the 
manv nights when we were in the desert the thermometei 
u below zero, and shrubs and other objects were in the 
morning covered with a thick coating of hoar-frost ; this low 
rr-ire being invariably followed shortly after sunrise by 
fETXS rS; scorched and peeled the skin from the 
faC “ In addition to this it may be mentioned that several 
i Kml Monarentlv whole flakes were seen, which, on being 
touched, feU topl^ces^ showing them to have been broken by 
