298 Peat Bogs. (July, 
in the clay, marl, or gravel, are found the “corkers,” or 
roots of the oak and yew, following the undulations of the 
ground, while above them—in horizontal layers, and sepa- 
rated from them by from about 4 to 10 or 12 feet of peat— 
are the roots of the deal forest, which at the sides of the 
hills join the oak roots, as shown in the accompanying 
sketch section. In a few lowland bogs, however, and in 
many bogs in the mountainous districts, the lower and upper 
systems of corkers will belong to deal trees, as if in such 
places there had been two distinct ages of deal forests. 
Some of the lowland or red bogs are of great depth, ina 
few places up even to 50 feet, but on an average they gene- 
rally do not exceed 20 or 30 feet, and often are much less. 
A typical red bog gives four kinds of peat: near the surface 
is a clearing of more or less living organic matter, from 3 to 
6 feet in thickness ; under this is white turf, then brown turf, 
and lowest of all black or stone turf. White turf is a nearly 
pure organic substance, very light when dried, burns quickly, 
giving out only a little heat, and leaves little or no ash. 
Fic. 7. 
al eS 
b * é 
Pca. tea cen ae Waa Fes Ayn 
A 
Mas PAT ae mp ask ahh 
a. Drift Hills or Derries. 0. Surface of bog. c. Dealcorkers. d. Oak corkers on gravel. 
Brown turf is always more or less mineralised. Black or 
stone turf is a chemico-organic production, and may contain 
such minerals as pyrite or marcasite; often it is semi- 
crystalline and seems to pass into lzgnyte, and when burnt it 
always leaves more or less ash. A variety in many bogs is 
locally called ‘“‘ Monagay”’ turf, which is very brittle, and 
full of the fragments and stems of flagger-like plants. 
Under monagay turf marl always is found, while under 
typical black turf there is usually gravel, suggesting that 
the monagay turf accumulated in a marsh. Another variety, 
always found at the very bottom of a bog when cut, is of a 
pale greenish-yellow colour: this, if allowed to dry, fully 
“melts” or disintegrates under the atmosphere, but if 
stacked when half dry it becomes a beautiful, hard, compact 
turf, that burns with a strong heat and brilliant light. 
The residue or ash of peat generally, but not always, is 
greater the more deeply the peat is seated. In some places 
mineral matter may be carried up into the peat from springs 
and the like; but the ash of peat seems usually due to the 
