prize8-4, Exercise 1: Stevenson's account of the Bell Rock as a source

Model answer (check the details):

What it can tell you: the sequence of the work season by season, the methods used (the floating lightship, the barrack on legs, the cutting and fitting of granite), the numbers of workmen, the weather and the setbacks, and Stevenson's own view of the problems. It is a first-hand account by the person in charge.

Its limits:
1. It was published in 1824, years after the work, and is shaped by memory and by Stevenson's wish to present himself well.
2. It was written in the middle of a dispute about credit with John Rennie, so it has an interest in stressing Stevenson's part (check).
3. It says little about the ordinary workers' own views, wages and fears, and nothing from their side.
4. Figures for costs and numbers may be rounded or presented to suit.

What to set beside it: the Board's minutes and accounts, Rennie's papers and letters, the workers' records, contemporary newspapers, and modern histories of engineering.

Conclusion: use the account for method and detail, and test claims of credit and difficulty against other sources.

Care: the same caution applies to any engineer's account of his own achievement.