1.   Brackley itself produced rather few people who impressed themselves on the historical record.

2.   Diagnoses are based on evidence accumulated about failure modes, operator observations of symptoms and historical records.

3.   Guide writers have a traditional obligation to honour the historical record, alongside their duty to point out present circumstances.

4.   Historical records for this time are incomplete.

5.   Historical records have often been kept in an ad hoc way, so that our information is not complete.

6.   However, the historical record is difficult to reconcile with this point of view.

7.   I am particularly grateful for his generous help with photographs, historical records and advice.

8.   Incomplete historical records have made the investigation more difficult.