Close-up image of the valve tower construction. The circular valve can be seen centre right. Two men standing on scaffolding poles and more seen above. It is annotated "Valve tower foundation. Concrete etc 3-9-59" Stamped on reverse "Richards Bros…
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"
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"