Tlie Agriculture of Pembrokeshire. 
73 
improves under good treatment and high feeding of the stock 
on it. The Silurian and Cambrian formations, which occupy 
so large a part of the county, vary very much in different 
localities. A large district from Haverfordwest to Narberth, 
and north of this line, and various tracts to the north-east ot 
the Precelly Mountains contain a deep, fertile, clayey soil, 
that forms excellent pastures, and formerly yielded good crops 
of wheat. In other places, again, there are many boggy, cold 
patches of little value ; at the higher levels there are extensive 
tracts of land with a thin peaty soil, which frequently carry little 
but heather, gorse, fern, and coarse grass ; again, where veins 
of slate and rab * appear, the soil will be usually well drained, 
and is often very good, especially if trap-rock adjoins. Slate- 
quarries are worked in the Precelly Mountains, and at one or 
two places between St. David's and Strumble Head. Wherever 
the trap appears, there is, as a rule, good soil ; this trap-soil is 
very stony, in fact, in some fields the stones are so thick, 
that it is almost like a shingle-beach to plough, and the 
accepted version is that the stones keep the soil open, and, 
being of a " sweaty nature," keep the roots moist. There is 
another reason why this trap-soil is so fertile, and which is not 
generally known by farmers, viz., that, according to the varying 
proportions of lime, magnesia, potash, and soda, some of the 
constituents of trap, so will the fertility vary. The presence of 
these saline matters explains the fertility of the soil, formed 
chiefly from these rocks decayed, and also the " sweaty nature " 
of the stones. These traps are in many places, especially at 
St. David's and along the coast to the north, very prominent 
objects ; here and there they rise in enormous beacons to the 
extent of some 500 or 600 feet above the sea-level. The 
ploughed field will extend up the slope of these, so long as 
there is sufficient soil. On these soils the best quality of barley 
in the county is grown ; and of such soils it is easy to believe 
a common legend, which relates how a farmer — recently arrived 
in such a district — picked up the stones, and carted them out of 
his field, for the sake of tidyness, and, as his crop failed, he 
carted them back again, for the sake of fertility. 
The soils over the coal-formation and the millstone-grit are 
the least productive in the county — not from the absence of the 
elements o( fertility, but because they contain elements poisonous 
to plant-life. There are in these formations frequent veins of 
blue, retentive shale, which with the present arrangements are 
almost unworkable. Nevertheless, fair crops of oats, barley, 
and roots are got from some parts of this tract, but drainage 
* Kab — a local name for broken or imperfect clay-slate. 
