The Letter Books contain copies of outgoing correspondence from the Secretary to missionaries (mainly the mission secretary).

Letters to Rev E C Stuart and other missionaries re the ill health of missionaries and the receipt of missionary journals; a list of suggestions for the improvement of the Krishnagur mission; yearly estimates for the mission; re finance; re the opening of a new college in Calcutta; re conferences to be held; letters to the Baptist Missionary Society re the work in Mulliana; a minute on the management of the missions and proposals for enlarging the system of management in North India; a letter from the Earl of Chichester, CMS President to Sir John Lawrence.