240 ON THE GEOLOGY AND STATISTICS 
Menai Strait, within two miles of Carnarvon, and to the 
north of that town, some small beds of iron are observed. 
As yet they have been applied to no useful purpose. It is 
probable, from occasional springs now and then met with 
of chalybeate waters, issuing from the Snowdon chain, that 
small beds of iron exist, imbedded in the transition-rocks. 
Manganese occurs in a thin vein, in Alt Dhu slate-quarry. 
Being mixed up with oil, it forms a tolerable brown paint. 
At Dolawen and Alt Dhu, in a sparry quartzy vein which 
crosses those slate-quarries, occasional traces of galena, or 
sulphuret of lead, are observed. Near Capel Curig, about 
twelve miles from Bangor^ on the Holyhead road, calamine, 
or carbonate of zinc, occurs. It is sent to Trefriew, and 
then shipped off for the founderies at Bristol. 
Though the coal measures shew themselves on the Car- 
' narvon side of the Menai basin, no workable seam has hi- 
therto been discovered. Peat is not found in any consider- 
able quantity, the nature of the rocks, the sudden slopes of 
their declivities, and the hollows being generally filled with 
watering to a great depth, preventing the formation of this 
article of fueL which would be so useful in a country devoid 
of workable coal. It may be mentioned, that, from the scar- 
city of wood, peat is employed to heat the oven for baking fer- 
mented wheaten and barley bread. The smoke of the peat 
being consumed in the process of combustion, no smell or 
offensive taste is given the bread thus baked. 
MENAI BASIN, ANGLESEA. 
Having taken a rapid survey of the more striking vege- 
table and mineralogical productions of the Carnarvon por- 
tion of the Menai basin, we shall now cross over the strait 
