Close-up image of digging the monolith for the dam. Four men can be seen in the trench to the left of the tall ladder digging with hand tools. It is annotated "Foundation for monolith 3-9-59"
Stamped on reverse "Richard Bros Penzance"
View along channel towards the McAlpine works on left. Several men building a scaffolding bridge across the channel.
The image is annotated "Downstream diversion channel 3-9-59"