announcing the doctrine of plural marriage. He later published an essay in defense of the practice in 12 monthly installments in the church periodical The Seer, which provides the most complete defense of the Mormon doctrine during this period. Pratt himself is considered one of the most influential early apologists for the LDS Church. Pratt's views were not always without controversy. In 1865, a majority of the First Presidency and the Quorum of the Twelve Apostles of the LDS Church officially condemned some of Pratt's doctrinal writings, including some of his articles from The Seer. They considered it to be misleading and questionable in relation to the actual doctrine of the Church. Though his many controversial beliefs have been rejected by Brigham Young and other Church leaders, Pratt's writings have nevertheless influenced many modern Mormon beliefs, including their concept of God and the doctrine of the gathering of Israel. In 1869, Pratt transliterated a portion of the Book of Mormon into the Deseret Alphabet. Pratt acted as Church Historian and Recorder from 1874 until his death. He edited many church periodicals and helped divide editions of the Book of Mormon and Doctrine and Covenants into verses and provided footnoted cross references. He served seven terms as Speaker of the House in the Utah legislature. Science publications and lectures Pratt was known as an accomplished mathematician and had a strong interest in astronomy. The disciplines combined with others to form in his mind a philosophy of what might be called 'early' Mormon cosmology. He offered science-based lectures on these topics to early Mormon audiences in Utah and published two related books. New and Easy Method of Solution of the Cubic and Biquadratic Equations was published in 1866, and Key to the Universe was published in 1879. The former is claimed to have been used as a textbook in England, Germany, and France, as Pratt was known as a talented mathematician even outside of Mormon circles. In October 1851, Orson Pratt taught mathematics in the 'Parent School' of the University of Deseret. The Thirteenth Ward School House was used for a classroom. On December 15, 1851, he commenced a series of lectures on astronomy and its religious implications, in the Council House. These educational efforts technically were part of an adult educational program. List of published works An Interesting Account of Several Remarkable Visions (1842) Project Gutenberg Kindle, epub, html, and text