How can I pull down the mercury of thermometer as there are bubbles in between?

Question

I had tried to jerk it many times but the bubbles still persists. Thanks a lot!!!

Answer 1

Try to heat the thermometer to (or near to) maximum of its scale, maybe it helps. But do it very slowly an carefully, because overheating would damage the thermometer.
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Answer 2

I thought the empty tube above the mercury was evacuated to prevent this. Anyway, there should be an empty reservoir in the top to help prevent the thermometer from bursting if it gets too hot. Heat it until the bubble rises into the reservoir and pops. Do this in a closed container in case it bursts anyway.