Final answer:
The specific major contribution of Noel Perkin as a missionary secretary is not detailed in the provided reference materials, but missionaries of his time played essential roles in cultural and religious exchanges.
Step-by-step explanation:
The major contribution of Noel Perkin during his term as a missionary secretary is not clearly documented within the provided reference materials. However, historically, missionaries like Noel Perkin have played significant roles in cultural exchanges and the spread of religious beliefs. Missionaries were instrumental in education and assimilation efforts, often bringing languages and customs of the conquering nations to the local populations in various colonies. While this information hints at the broad impact missionary secretaries like Perkin might have had, it does not pinpoint his specific contributions.