When did assistants work for Pitt-Rivers?

The following table was created by Mark Bowden; we are very grateful to him for providing us with the information, first published in his paper, 'From antiquarianism to archaeology: Pitt Rivers and his contemporaries' in Heather Sebire Pursuits and Joys: Great Victorian Antiquaries and Intellects published by Cambridge Scholars Publishing.

The chronology of Pitt Rivers’ excavations in Cranborne Chase and their publication against the periods of employment of his assistants or ‘Clerks’: this indicates that Claude Gray, who alone was present for the whole of the campaign published in Volume 3 but for none of the other work, may be responsible for the very fine contextual record achieved at Bokerly Dyke and Wansdyke.