From Herborg Blacksmith to Vestas - Wind Power for the World: The Rise of Modern Wind Energy - page 270

branches of the T, and with the central branch screwed onto the
rotor shaft. The sail wing was made from Dacron, the material that
is also used for sails on boats.
For the rotor shaft support I made a simple shaft box arrange-
ment with two ball bearings mounted on a lattice structure fitted
to an ordinary farm wagon. We could then take the wagon out on a
field, place it with the rotor in the correct position in relation to the
wind and in various ways measure the yield of the rotor in order to
see how the sail wing worked.

Figure 9.2 Testing of the rotor on the field, 1977.

With this experimental rotor I experienced my first (but not
last) wreck. As in the case of so many other accidents I could have
told myself that this go wrong. The fact was that I, faithful

to the tradition, had made the rotor running anti-clockwise.
Traditionally wind roses would rotate in the clockwise direction,
whereas Dutch windmills and windmills with adjustable narrow
vanes would rotate anti-clockwise. In normal circumstances the
direction would have been without practical importance, but
that did not apply for the experimental rotor, as it was assembled

must