Steampunk Canada

Fitzroy"s Storm Glass

Fairly easy to obtain chemicals are used to create a weather prediciton device in a glass vial. Potassium Nitrate might be a bit difficult to get these days but was used for foot baths and in making pickles.

You might be able to find the potassium nitrate in a specialty gardening or hydroponics store, as it's also a common ingredient in fertilizers.