How Does Priestley Show That Tension Is at the Heart of the Birling Family?

Priestley presents tension in various ways withing in the Birling family. At the beginning of the play, Priestley creates his tension by changing the colour of the lighting. The start is a ‘low and intimate pink’ which could suggest a hidden tension within the family home. After the inspector arrives the lighting changes to a ‘bright, harsh white light’ which makes the family look like they are in the spotlight of a police interrogation. This shows that there is tension at the heart of the Birling family as it may be hidden to begin with, certain comments give the reader a small insight to what is hidden and not spoken of.
The light of being under interrogation works well as Inspector Goole is there is to accuse them of a crime and then asks them a series of questions to reveal the truth and the all the tension they have hidden. One of the hidden tensions within the Birling family is the fact that Mr. Birling talking about his business with Gerald at the dinner table celebrating Shelia and Gerald’s engagement, ‘Now, Arthur, I don’t think you ought to talk business on an occasion like this’.
This presents hidden tension because Mrs. Birling doesn’t say what she really thinks, which could be that Mr. Birling talks about his business too much. Mr. Birling does not follow instructions for long proving that he cares more about his work than his own family. As any wife would be annoyed with this as they think that it should always be the other way around, Mrs. Birling is the same but knows she will not get anywhere so sighs and leaves him to get on with it.