La pedra en sec. Materials, eines i tècniques tradicionals a les illes ...

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slope is created by stepping the terrace
wall, can also be considered as an
exception. They are normally to be
found in the polygonal retaining walls
built by civil engineers on roads in the
19th century.
Some writers have pointed out as a
singular feature of vegetables gardening
terrace walls is hat they are 'broken',
that is to say the facing slopes at
the bottom of the retaining wall whereas
it is straighter at the top. Such a
building peculiarity is not to be found
in all vegetables gardening terrace
walls, but the fact that the sa Regata
retaining wall (the highest in Majorca)
shows this feature would lend support
to the idea of greater drystone wall
solidity when it has a broken slope.
Although, in the traditional knowledge
the slope and the height of the wall
are held to be the important aspects
leading to stability, there is no general • Marge escalonat
agreement on a formula for working
them out. Observation of the existing
great variety would suggest that the
influence of the master masons is
greater than the apects mentioned
above. Nevertheless it should be
pointed out that the greatest slopes
are to be found on road retaining
walls where they reach their greatest
heights. In these cases, slopes ·over
35% can be observed whereas terrace
walls slopes for cropland are
usually between 15% and 25%.
Tools required
Small stone hammer, large stone hammer,
stonecutter's hammer, pointed
sledgehammer, bevel square, levelling
line, two-handed basket, triangular
hoe, tope, burin, mallet.