William T. Gregg
1818-1897

William T. Gregg was born in Ireland in 1818 and probably died about 1897 as Mrs. Gregg is listed as a widow in Plainfield, NJ. The 1880 census of Brooklyn, NY states that he was 62 years old and was born in Ireland. Prior to 1843 he lived at 13 Doyers Street. He worked with Michael Rupp from 1844 to 1853, as Gregg and Rupp, at the corner of Pearl Street and made mathematical instruments. He later worked with his son, W.T. Gregg Jr., as Gregg and Son (1873-1887) at 110 Wall Street; his son continued under the same name until 1891. William T. Gregg Jr. was born in Brooklyn in 1850 and died in Yonkers, NY, on March 8, 1916. In 1891 Gregg senior was living in Plainfield, NJ.

In 1894 the assets of William Gregg were acquired by William & David Mogey (1880s-1920), telescope makers. They had a shop in New York N.Y., later moved the shop to Bayonne, N.J., then in 1908 they moved to Plainfield, N.J.

MICHAEL RUPP (1818 - 1899)
New York City

He was born in France in 1818. He died in Brooklyn, New York on November 12, 1899. He came to the United States in 1829 and to New York City in 1844.

New York City directories: 1844-45 Rupp, Michael, h. 40 Forsyth. 18444-53 Gregg & Rupp, mathematical instruments, William T. Gregg and Michael Rupp. 1853-1899 Rupp, Michael, mathematical instruments.