A tunnel must be bored, for I forget how far, through virgin rock, with the help of inadequate tools and unskilled labour, and this tunnel must be finished by a certain date.

A hundred unexpected difficulties arose, and one by one were conquered.

Great dangers must be run, and were avoided, while the responsibility of this tremendous engineering feat lay upon the shoulders of a single individual, Oliver Orme, who, although he had been educated as an engineer, had no great practical experience of such enterprises.
Truly the occasion makes the man, for Orme rose to it in a way that I can only call heroic.

When he was not actually in the tunnel he was labouring at his calculations, of which many must be made, or taking levels with such instruments as he had.

For if there proved to be the slightest error all this toil would be in vain, and result only in the blowing of a useless hole through a mass of rock.