During his ministry he has been absorbed in two specialties, the one being his principal and the other his secondary object of pursuit.

The former is the critical study of the Bible originals and the development of the Bible's thought, and the latter is the tracing of Divine Providence through history. Of the results of his Bible study, he has written and printed very much, but not in pamphlet or book-form. Upon history, his researches have been mostly of local bearing, being developments of church and local annals. In October, 18(35, he delivered an historical address upon his first church at East Millstone, then ten years old ; in 18t;8, another upon his church at Yonkers, then twenty-five ; and in 1883, a third upon the same church, then forty years old. All these were published by the congregations. His Thanksgiving sermon of 1866 wius also published by his people, and his Centennial Thanksgiving sermon (1876) on "Our American Kepublic, the Child of Special Providence," was called for by a representation from the uniting congregations that heard it, and published. The General Synod of the Reformed Church published also a sermon he preached before it in 1S74 on " Ofierings to the Lord," being its " Annual Sermon on Benevolence." In 1876, Dr. Cole himself published a large octavo volume, the fruit of very great labor, giving the genealogy of his own Holland family from 1580 to date. In October, 1882, at the call of his fellow-citizens of Yonkers, he delivered in the open air, to many thousands of people, a bi centennial oration commemorative of the founding of the Manor (now the city) Hall of Yonkers, which was printed and very widely circulated. In 1883 and 1884 he edited the " History of Rockland County," alluded to above. In Sei)tember, 1884, as president of the General Synod of the Reformed Church, he presided at the installation of Rev.