Measuring Weather

Today we continued with our weather unit study by finding out how the weather is measured. First we made our own thermometer (pictured below). You just need a glass bottle with a lid, a straw, blue-tac and a ruler. First make a hole in the lid and push the straw through. Seal around the straw to make it airtight with blue-tac. Fill the bottle with water (food colouring makes it easy to see). Screw on the lid and the water will rise up the straw a little. Stick the ruler to the bottle. The level of water in the straw is room temperature. Next we placed our thermometer in a bowl of hot water and watched the temperature rise - the water rose up the straw. Next we plunged the thermometer into icy water to see the temperature fall again. We explained what was happening in therms of water molecules becoming more active with the heat and spreading upwards.

You could take this experiment further and mark the points of boiling water and melting ice (O°C and 100°C) and then divide the space into 1°C intervals. We decided to try using some commercial thermometers to find the temperatures of water samples (top).

Next we made an anemometer and weather vane to measure the speed and direction of the wind. There is a good tutorial in the book "Make it Work - Weather". It hasn't been very windy today but we were still able to test our measuring devices in the garden.

Weather vane by L

Anemometer by R (Wind blowing from the left will push up the gauge, the stronger the wind the higher the indicator match will rise)