{p. 40}

Two things stand out in his report:

1. The obvious determination to fit some explanation, no matter how
farfetched, to the Mantell sighting.

2. The impossibility that Venus--a tiny point of light, seen only with
difficulty--was the tremendous metallic object described by Mantell
and seen by Godman Field officers.

With Venus eliminated, I went to work on the balloon theory. Since I
had been a balloon pilot before learning to fly planes, this was
fairly familiar ground.

Shallett's alternate theory that Mantell had chased a Navy research
balloon was widely repeated by readers unfamiliar with balloon
operation. Few thought to check the speeds, heights, and distances
involved.

Cosmic-ray research balloons are not powered; they are set free to
drift with the wind. This particular Navy type is released at a base
near Minneapolis. The gas bag is filled with only a small per cent of
its helium capacity before the take-off.

In a routine flight, the balloon ascends rapidly to a very high
altitude-as high as 100,000 feet. By this time the gas bag has swelled
to full size, about l00 feet high and 70 feet in diameter. At a set
time, a device releases the case of instruments under the balloon. The