While Harry was doing this, Ralph sawed out four wooden dirigibles shown at b, 8 inches long, 3 inches across at the widest part, and 1⁄4 inch thick.
A hole was drilled through the centre of each propeller and another in the flat stern of each air-ship. The pivots for the propellers were flat-head wire nails small enough for the blades to revolve freely, but driven securely into the air-ships.
These were now fastened at the ends of the arms of the anemometer by attaching two strips of basswood to each ship by wires. The strips were to hold the ships in the proper position facing in the direction of motion, which was always the same, no matter in which direction the wind was blowing.
The upper ends of these strips were brought together, and securely fastened under one of the bolts by wires.
As the anemometer revolved, centrifugal force sent the air-ships out as far as the basswood strips would allow.
Fig. 99. The Zeppelin wind vane
It was a very interesting fair weather toy, but the first gale, while having no effect on the anemometer other than to make it spin around at terrific speed, nearly wrecked the ships by slamming them against the standard. So the boys always took the ships off at night, and put them on again when they wanted to give an exhibition.
The propellers were gilded and the ships painted in bright colours.