What are some hidden elements that are related to weather observation in Little Alchemy 2?

In Little Alchemy 2, there are several hidden elements related to weather observation that you can discover. Here are some of the key combinations and steps to unlock them:

1. Thermometer:
- Combination: Glass + Mercury
- Steps:
- First, create Glass by combining Sand + Fire.
- Next, create Mercury by combining Metal + Water.
- Finally, combine Glass + Mercury to create a Thermometer.

2. Barometer:
- Combination: Air + Pressure
- Steps:
- First, create Air by combining Fire + Water.
- Next, create Pressure by combining Air + Air.
- Finally, combine Air + Pressure to create a Barometer.

3. Rain Gauge:
- Combination: Glass + Rain
- Steps:
- First, create Glass by combining Sand + Fire.
- Next, create Rain by combining Cloud + Water.
- Finally, combine Glass + Rain to create a Rain Gauge.

4. Weather Vane:
- Combination: Metal + Wind
- Steps:
- First, create Metal by combining Fire + Stone.
- Next, create Wind by combining Air + Air.
- Finally, combine Metal + Wind to create a Weather Vane.

5. Anemometer:
- Combination: Wind + Tool
- Steps:
- First, create Wind by combining Air + Air.
- Next, create Tool by combining Metal + Human.
- Finally, combine Wind + Tool to create an Anemometer.

These combinations will help you unlock the hidden elements related to weather observation in Little Alchemy 2. Experiment with these steps and enjoy discovering new elements!