Ill 
Account of the celebrated Slide of Al^nach. 
crowns, they began the construction of the slide, and completed 
it in the spring of 1818 
The slide of Alpnach is formed entirely of about S5,000 
large pine trees, deprived of their bark, and united together in 
a very ingenious manner, without the aid of iron. It occupied 
about 160 workmen during eighteen months, and cost nearly 
100,000 francs, or L. 4250* It is about 3 leagues, or 44,000 
English feet long, and terminates in the Lake of Lucerne. It has 
the form of a trough, about 6 feet broad, and from 3 to 6 feet 
deep. Its bottom is formed of three trees, the middle one of 
which has a groove cut out, in the direction of its length, for re- 
ceiving small rills of water, which are conducted into it from 
various places, for the purpose of diminishing the friction. The 
whole of the slide is sustained by about 2000 supports, and in 
many places it is attached, in a very ingenious manner, to the 
rugged precipices of granite. 
The direction of the slide is sometimes straight, and sometimes 
zig-zag, with an inclination of from 10*^ to 18°. It is often car- 
ried along the sides of hills and the flanks of precipitous rocks, 
and sometimes passes over their summits. Occasionally it goes 
under ground, and at other times it is conducted over the deep 
gorges by scaffoldings 120 feet in height. 
The boldness which characterises this work ; the sagacity dis^ 
played in all its arrangements, and the skill of the engineer, 
have excited the wonder of every person who has seen it. Be- 
fore any step coidd be taken in its erection, it was necessary to 
cut several thousand trees to obtain a passage through the im- 
penetrable thickets ; and as the workmen advanced, men were 
posted at certain distances in order to point out the road for 
their return, and to discover, in the gorges, the places where the 
piles of wood had been established. M. Rupp was himself obliged, 
more than once, to be suspended by cords, in order to descend pre- 
cipices many hundred feet high ; and in the first months of the 
undertaking he was attacked with a violent fever, which depriv- 
ed him of the power of superintending his workmen. Nothing, 
however, could diminish his invincible perseverance. He was 
carried every day to the mountain in a barrow, to direct the la- 
* These dates must be erroneoui^, as Mr Playfair saw the slide in operation in 
