In a mine with shafts opening at the same level, natural ventilation once established will be effective during cold weather, as the downcast will have the temperature of the outside air, while the upcast will be filled with the warm air of the mine.
The use of two independent connexions - whether separate pits or sections of the same pit, between the surface and the workings - is necessary for the service of the ventilation, fresh air from the surface being carried down one, known as the " downcast," while the foul or return air of the mine rises through the other or " upcast " pit back to the surface.
Pierre, with downcast eyes, drank out of his glass without looking at Dolokhov or answering him.
Prince Andrew came up to her with downcast eyes.
He rode hurriedly from the battlefield and returned to the Shevardino knoll, where he sat on his campstool, his sallow face swollen and heavy, his eyes dim, his nose red, and his voice hoarse, involuntarily listening, with downcast eyes, to the sounds of firing.
When the mine is free from gas, the furnace may be worked by the return air, but it is better to take fresh air directly from the downcast by a scale, or split, from the main current.
"Countess..." said Denisov, with downcast eyes and a guilty face.
In any case whether natural or artificial means be employed, a mine can only be ventilated properly when it has at least two distinct openings to the surface, one an intake or " downcast," the other a chimney serving as an " upcast."
Ignat left off smiling, adjusted his belt, and went out of the room with meekly downcast eyes.
This is effected by carrying through the workings a large volume of air which is kept continually moving in the same direction, descending from the surface by one or more pits known as intake or downcast pits, and leaving the mine by a return or upcast pit.
"Can he really be going away leaving me alone without having told me all, and without promising to help me?" thought Pierre, rising with downcast head; and he began to pace the room, glancing occasionally at the Mason.
God is my witness, I didn't know-" he repeated, stressing the word "God" so unnaturally and so unpleasantly that Princess Mary stood with downcast eyes not daring to look either at her father or at Natasha.
Sonya listened silently with downcast eyes to the countess' cruel words, without understanding what was required of her.