The following quote is
taken from The Makers of Surveying Instruments in
American Since 1700 by Charles E. Smart,
"James Foster, Jr. was
born in Baltimore, Maryland in 1814 and died in
Hamilton County Ohio in 1873. Cincinnati directories
list as follows: 1839-40 First listed - employed at
Wells and Foster, Mathematical instrument makers.
This listing continued through 1844. Also listed as a
machinist in 1839 and 1840. And in 1846 listed as
James Foster, Jr. Mathematical and Philosophical
instrument maker. The James Foster, Jr. Company was
last listed in 1880."