All you need to use the Pocket Weather Foecaster is a barometer
to read rising or falling pressure and an indication of wind direction.
the forecaster interprets these readings into one of 26 different
forecasts, providing an extremely accurate weather prediction
for the next 12 hours.
The Zambretti Weather Forecaster is used in conjunction with
a barometer. It interprets the reading of a barometer into one
forecast from a large selection of permutations after making allowances
for variable factors such as wind direction, a rising, falling
or steady barometer and summer or winter season. The forecasts
are based on actual experiences and results obtained over a period
of years. A severe test proved that 91.7925% of the forecasts
obtained with this instrument are correct.