• This report is dated December 1954. This extract is from the annex attached to the report which gave detailed findings about the findings of British scientists about the effects of a thermonuclear bomb (which was more powerful than an atomic bomb).
• The report was presented to the British Cabinet by the Minister of Defence.
• The information came largely from the tests carried out by Britain on various Pacific Islands in the 1950s.
• Some of the information came from US scientists. However, there was so much concern about spying that the US was not always willing to give data even to Britain. We now know that there were numerous Soviet spies in Britain's nuclear programme.
• The main aim of the report was to help the British government plan defence measures to protect the population as well as possible against nuclear attack.
• Megatons mean million tons of normal explosive like TNT.
• Ground burst meant the bomb exploding when it hit the ground. Air burst meant exploding in the air above a target (as happened at Horoshima).