I want to know the answer to the following question:
Who started trials in August 1936?
All the background I'm provided with is that "The British high-definition TV service started trials in August 1936 and a regular service on 2 November 1936 using both the (mechanical) Baird 240 line sequential scan (later to be inaccurately rechristened 'progressive') and the (electronic) Marconi-EMI 405 line interlaced systems.". Is that enough to answer the question?
Answer: yes