According to his sister Harriet Martine Dean, his interest in armour began at age six, when he "spent hours examining a helmet" while visiting the collection of the estate of the late Carlton Gates in Yonkers (d. 1869), a family acquaintance, whose holdings included Asian and Medieval arms and weaponry. in 1876, aged about nine, he tried to buy the helmet but was outbid. In 1877, at age 10, he purchased two 16th century daggers from the collection of Henry Cogniat and started his personal collection.