Marine Navigational Octant by W. DeSilva of Liverpool, Brass & Bone Inlay, Mid-19th Century

Mid-19th century brass octant with two eyepieces, by W. DeSilva of Liverpool England. Brass frame and bone inlay scale, with wooden handle. Moderate patina on brass, bone is in good shape. One eyepiece has crack in the brass casing that has been drilled out. Case has a nice level of patina with associated nicks and age cracks.