We found that from top to bottom of the fall was 45 yards.

There was all the appearance of immense thickness, especially towards the upper part.
Christian had placed his candle in a niche in the column, while he arranged the string for measuring the fall, and the effect of the spark of light at the top of the long steep slope was extremely strange from below.

The whole scene was so remarkable, that it required some effort to realise the fact that I was not in a dream.

Christian stood at the top invisible, jodeling in a most unearthly manner, and developing an astonishing falsetto power, only interrupting his performance to assure me that he was not coming down again; so I was obliged to measure the breadth of the fall by myself.

I chose a part where the ice was not very steep, and where occasional points of rock would save some of the labour of cutting steps; but even so it was a sufficiently tedious business.
The string was always catching at something, and mere progression, without any string to manage, would have been difficult enough under the circumstances.