Diana Craig

the weather today will be much the same as the weather yesterday.

Meteorological organizations and museums may offer some equipment, or look online. Organizations and websites are also a good source of inspiration for experiments and homemade equipment. You could start with the following:
www.salemclock.com/weather/weather01.htm
www.miamisci.org/hurricane/weatherstation.html
www.rmets.org/weather/observing/index.php

But it wasn’t until the appearance of primitive bacteria, millions of years ago, that the vital component of the air we breathe first materialized.
Using the power of the sun in a chemical process called photosynthesis, these bacteria absorbed carbon dioxide from the atmosphere and gave off a new gas: oxygen.