Page:Whymper - Scrambles amongst the Alps.djvu/105

Rh the way in which the waste power of nature has been applied for the reduction of the difficulties of the undertaking. There is not a single steam-engine on the works: everything is done with compressed air, or by hydraulic power. Just one half of the tunnel was driven at the end of October 1866, after more than nine years of labour. The third quarter was finished by the end of 1868, Unless extraordinary obstacles are encountered, the two ends will probably meet in February 1871;