细节
An oxcidised brass lattice framed sextant by W.S. Jones
signed on the arc W.S. Jones, Holborn, London with inset silvered scale, adjustable telescope mount, seven shades, adjustable mirror, index arm with silvered vernier scale and swivel magnifier, tangent screw fine adjustment with clamp, rose wood handle, three telescopes and trade label for D. McGregor & Co., 36 Brymner St., Greenock in fitted mahogany case -- 1in. (29cm.) wide
See illustration
signed on the arc W.S. Jones, Holborn, London with inset silvered scale, adjustable telescope mount, seven shades, adjustable mirror, index arm with silvered vernier scale and swivel magnifier, tangent screw fine adjustment with clamp, rose wood handle, three telescopes and trade label for D. M
See illustration