From 1901 he worked with George Reisner who was excavating at Giza and Naga el-Deir,[2] before studying at the University of Göttingen in Germany in 1902–03 and then returning to Egypt.

[5] After leaving the Army in 1919, Mace went to New York to work on the restoration of Ancient Egyptian artifacts for the Metropolitan Museum, before returning to lead the excavations at Lisht in 1920.

He was still working there when, in December 1922, the Metropolitan Museum agreed to loan him to the archaeologist Howard Carter to support the clearance of Tutankhamun's tomb.

Given the size and scope of the task in cataloguing and clearing the tomb, Carter sought help from Albert Lythgoe of the Metropolitan Museum's Egyptian excavation team, who readily agreed to the loan of a number of his staff, including Mace.

[7] Arriving on 25 December 1922,[8] Mace was a part of a small team of experienced archaeologists and experts, led by Carter and including Alfred Lucas, Arthur Callender and photographer Harry Burton.

[13] He also played an important role in reporting and advising during Carter's legal dispute with the Egyptian authorities, that led to the temporary closure of the tomb in 1924.

[15] Spending the next four winters in England and the French Riviera, Mace died on 6 April 1928 at a nursing home in Haywards Heath, Sussex.