"He is listed in the Newark directories from 1842-1843 through the 1849-50 issue as follows:  Dowling, Michael, math instrument maker, one address is 158 Market Street.  The New Jersey State Department of Health, State Registrar of Vital Statistics, Trenton, N. J. under date of 24 January 1966 could find no record of Mr. Dowling's death.  The Mt. Pleasant Cemetery Co., Neward, J. J. in letters dated 13 and 17 September 1965 state that Michael Dowling was interred in single grave May 16, 1853 and that he was 63 years old at the time of his death."

Reference:  Smart, Charles E.   The Makers Of Surveying Instruments In America Since 1700  Troy, New York:  Regal Art Press.  1962