HARRIS, Thaddeus Mason, clergyman, born in Charlestown, Massachusetts, 7 July, 1768; died in Dorchester, Massachusetts, 3 April, 1842. He was a descendant in the sixth generation of Thomas Harris, of Ottery St. Mary, Devonshire, England. His father was a Revolutionary patriot, who died during the war, leaving his family destitute. Thaddeus was sent to earn his living with a farmer in the township of Stirling, Massachusetts, and received some schooling with the farmer's children. He entered the school of Dr. Morse, a suspected Tory, who prepared him for college, and in 1787 he was graduated at Hat-yard. Through the influence of friends he was in this year invited to become private secretary to General Washington, but was prevented by an attack of small-pox. He taught at Worcester a year, studied theology, and in 1781 was appointed librarian at Harvard. He accepted a call in 1793 from the 1st Unitarian church at Dorchester, and remained its pastor till three years before his death. Harvard gave him the degree of D. D. in 1813. He published "Discourses in Favor of Freemasonry" (Boston, 1803); "Journal of a Tour of the Territory Northwest of the Alleghany Mountains" (1805); "A Natural History of the Bible" (1821); "Memorials of the First Church at Dorchester" (1830); and "Biographical Memoirs of James Oglethorpe" (1841).--His son, Thaddeus William, entomologist, born in Dorchester, Massachusetts, 12 November, 1795; died in Cambridge, Massachusetts, 16 January, 1856, was graduated at Harvard in 1815, studied medicine, and practised at Milton Hill, Massachusetts, until 1831, when he was appointed librarian of Harvard. For several years he gave instruction in botany and natural history, and was the originator of the "Harvard students' natural history society" and a member of the "Massachusetts horticultural society." He was appointed in 1837 a commissioner for a zoological and botanical survey of Massachusetts, and after much research published a catalogue of the insects of that state, which enumerated 2,350 species. This, with his other extensive catalogues and his collection of insects, was purchased by the Boston society of natural history. His report on "Insects Injurious to Vegetation" (Boston, 1841, enlarged ed., 1852) was published by the legislature, and is a contribution to science of the highest practical value. Sir. Harris also took a deep interest in antiquarian research, and published more than fifty papers on this subject.--His son, William Thaddeus, scholar, born in Milton, Massachusetts, 25 January, 1826; died in Cambridge, Massachusetts, 19 October, 1854, evinced a fondness for books at an early age, and, in consequence of a physical infirmity, reading was his sole amusement. He was graduated at Harvard in 1846, and studied law, but was prevented from practising by delicate health. He edited, for the Massachusetts historical society, Hubbard's "History of New England," with new and important notes (Boston, 1848); the third volume of the "Historical and Genealogical Register" (1849); and published "Epitaphs from the Old Burying Ground at Cambridge" (1845).