184 
ANNALS NEW YORK ACADEMY OF SCIENCES 
under cover, conditions not exhibited in the trenches; for these one must 
depend on Fayol’s descriptions. 
Near the village of Longeroux on the eastern side of the Pegauds area, 
the outcrop shows only a few inches of coal: The Gres Noirs and a higher 
bed, that of les Pourrats, are given off as the bed thickens and the intervals 
between them increase rapidly. The Grande Couehe soon attains the 
thickness seen in the Longeroux trench; in l’Esperance, it is divided by the 
two partings, the Banc des Chavais above and the Banc des Roseaux below, 
of which the former disappears in Foret while the latter continues into 
Saint-Edmond, where the bed becomes practically one, with a thickness of 
10 to 12 meters. The Banc des Brouillages or Banc du mur, not included 
in the thickness given, is continuous from the trench of Longeroux to the 
east end of Saint-Edmond, beyond which the writer did not recognize it with 
certainty. 
This much one may gather from the trenches as they now exist; for the 
rest he must turn to Fayol. 
Followed westwardly, the Grande Couehe begins to divide in the Grande 
Tranchee. A small bed, known farther west as the Sixth, is seen three 
meters below the Grande Couehe at the east end of that trench, but the 
interval increases to 23 meters at the west end. 1 In the Tranchee de l’Ouest, 
the bed continues to divide, and before the end of that trench has been 
reached there are six beds, so that the single bed near the village of Longe¬ 
roux had been divided into eight beds, distributed in a vertical section of 
more than 200 2 meters. In the region of Saint-Augustin, five of the six 
branches have been followed to their disappearance along the strike. There 
is gradual thinning of the coal and at last a rapid disappearance in the 
sandstone which there forms the mur of the Grande Couehe. 3 The sandy 
wedges entering the bed in the Grande and Ouest trenches increase and the 
coal decreases. 
Followed down the dip, the Grande Couehe gradually becomes thinner 
and at length disappears toward the depth of 350 meters. In one pit, the 
coal becomes only two to three meters thick at 225 meters, where it is of 
good cjuality and without intercalation; but at 36 meters farther, there 
remain only a few films of coal, and the Grande Couehe is represented by a 
dozen streaks of carbonaceous shale, separated by shales including a thin 
sandstone. 4 
To sum up: The Grande Couehe, outcropping in the form of a very 
1 Fayol: Commentry, p. 265. 
2 Fayol: Commentry, p. 24. 
3 Fayol: Commentry, pp. 282-283. 
4 Fayol: Commentry, pp. 24, 280. 
