SHORT NOTES ON PROFESSIONAL SUBJECTS. 
169 
108. Description oe the Swiss Pile-driving Machine. 
(Communicated by Major Downes, K.A.) 
ELEVATION 
F I C .3 
GUIDE ROD 2" DIAMETER 
a 
The “ monkey ” (Pigs. 1 and 2) should be at least 12 ins. in diameter, and 
about 3 or 4 ft. in length. The handles are made of rope or iron rods, the monkey 
of wood. Pour men can work it easily. 
A hole ( d ) of 2-^ ins. diameter is bored down the centre of the monkey and 
burnt smooth. 
Each picket to be driven requires to have a hole bored in the centre of the head 
to a depth of 9 ins. and of 2-g- ins. diameter. Into this a guiding rod of 2-in. iron 
6 ft. long is temporarily placed, and the monkey is worked up and down upon it. 
The pickets should have an iron band round the head, to prevent them from 
splitting. 
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