182 
ANNALS NEW YORK ACADEMY OF SCIENCES 
within five minutes walk from the shaft. Still nearer that mine is the 
abandoned Tranchee de Goutilloux, now almost filled with waste. There 
one can still see the upper portion of the Gres Noirs group, which, at one 
time, was fully exposed in the south wall. This is only a few rods south 
from the Tranchee de Saint-Edmond, in whose south wall the Gres Noirs 
are not reached. 
The enormous trenches on the west side of the Pegauds area are utilized 
no longer for mining but as dumping grounds for waste from the shaft and 
washeries as well as from the great iron works in Commentry. The Grande 
Couehe has been removed and the lower part of the well has fallen, so that 
for variations in the coal bed one must depend on descriptions given by Fayol. 
But the upper part of the southerly, becoming easterly wall still remains 
intact, exhibiting as clearly as ever the vagaries of deposit which that author 
has described with great detail. As the exposed conditions are not unlike 
those already observed, it is unnecessary to dwell upon them. 
Grande Tranchee. 
The Grande Tranchee is north from the mine, between it and the city 
of Commentry. It extends approximately east and west. Before abandon¬ 
ment it was 750 feet long by 200 feet deep, but it is now much shorter and 
less deep, as waste has been dumped at both ends and along the north side. 
The exposures along the south wall are thoroughly characteristic; local 
faultings, confined to two or three beds; disappearance of single beds or of 
petty faisceaux of beds; local crumplings and other phenomena already 
familiar are numerous. The sandstone overlying the Grande Couehe in 
Saint-Edmond persists. This trench was connected by tunnel at the west 
with the tranchee de l’Ouest et du Pre-Gigot. 
o 
Tranchee de l’Ouest et du Pre-Gigot. 
The trenches of l’Ouest and du Pre-Gigot were formerly separate, but 
now are continuous. The Grande Couehe has been followed in the works 
from Saint-Edmond into 1’Quest, but one carried from Longeroux to this 
extraordinary excavation might well imagine that he is still at the Gres Noirs 
horizon. 
The yellow sandstone is seen in many places at the top of the wall, over- 
lying a gray sandstone, weathering less strongly yellow, which is quarried 
as building stone at the farther end of the trench. This rests on a great 
mass of shale and sandstone, which in turn rests on coals and shales, while 
at the bottom is a gray, irregular sandstone, with an indefinite coal deposit. 
