This telescope was used by the Signal Corps of the Confederate States of
America during the Civil War. It has an achromatic objective, a four-element
erecting eye piece, and a three-draw brass body covered with leather. Negretti
& Zambra made and sold a wide variety of mathematical, optical, and
philosophical instruments. The firm was established by Italian immigrants in
London in 1850, and became Negretti & Zambra, Ltd., in 1948.
Ref: Gloria Clifton, Directory of British Scientific Instrument Makers,
1550-1851 (London, 1995), p.198.