Jack Calvin

A fellow officer in Robertson's Engineer circle: John David Calvin, born November 20, 1883, the elder of two brothers serving in the Canadian Engineers; his brother Reginald is the diary's "Rex Calvin." Robertson rides up the line with him in February 1916, and in May 1917 notes that "Jack Calvin's Capt'cy gazetted so that leaves me 5th on the list": the promotion Robertson was measuring his own prospects against. In June 1918 Jack Calvin confirms, in person, the secondhand news of Robertson's new command of a transport-and-bridging section.

The Corps seniority list Robertson kept has both brothers, one above the other, with the same seniority date of 2 December 1915: "Calvin, J.D.," pencilled "Capt." and "England; Adjt. 5th Div.," and the second Calvin just below. The seniority list attaches the 5th Division adjutancy to Jack, while the diary attaches the 5th Division to Rex; whether both brothers served with that formation, or the pencilled note belongs to the other, is not clear from these sources.