I need help with finding some sources of error! My experiment is that there is one candle lit and five different sizes of beakers being upside down onto the candle (one at a time) and seeing how long it takes for the candle to burn out for each beaker.

Question

I already have one but need three --- the one I have is that someone walks by your table and the wind makes your fire smaller without your knowledge. Then you put your beaker on the candle, which ultimately affects how long it takes for the candle to burn out, since the size of the fire isn't at it's largest.