During February the workmen had to contend against a sheet of water which sprang from the ground.

They were obliged to employ powerful pumps and apparatus of compressed air to drain it off, so as to close up the orifice from which it issued, just as leaks are caulked on board ship.

At last they got the better of these unwelcome springs, only in consequence of the loosening of the soil the wheel partially gave way, and there was a landslip.

The frightful force of this bricked circle, more than 400 feet high, may be imagined! This accident cost the life of several workmen.

Three weeks had to be taken up in propping the stone revetment and making the wheel solid again.
But, thanks to the skill of the engineer and the power of the machines, it was all set right, and the boring continued.
No fresh incident henceforth stopped the progress of the work, and on the 10th of June, twenty days before the expiration of the delay fixed by Barbicane, the well, quite bricked round, had reached the depth of 900 feet.