THE PLAIN QUADRANT, English, mid-18th century, made of finely-grained boxwood in the form of a quarter circle, 6" (15 cm) in radius and 9/32" (7mm) thick. The borders are ruled, and the arc is divided every degree from 0 to 90, with calibrations every 10° and intermediate 5° positions marked with triple-dot patterns. The quarter circle's center is pierced with a hole for supporting a string and plumb bob (not present). Condition is very fine throughout. Sometimes referred to as a "mariner's" or "plain" quadrant, this form is useful for simple measurement of solar or stellar altitudes. The angular altitude of the pole star, or the midday sun, leads directly to one's latitude. The plain quadrant also can serve for simple inclination measurements, e.g., in construction, surveying, gunnery, etc. $1950.

BOX SEXTANT OUTFIT WITH GIMBALLED ARTIFICIAL HORIZON MIRROR, English, c.1820, signed "Simms, London." The 2-3/4" (7 cm) diameter brass sextant is complete with inlaid silver scale and one-arcminute vernier, scale magnifier, geared index arm, mirror adjusting tool, peepsight, single draw telescope, two swing-away filters, and screw-on handle/cover. The cover is engraved with tables of tangents and arctangents. The original fitted mahogany case contains a weighted plane mirror in double gimbal rings, which sets up on folding supports in the case top. This is a novel approach to providing a perfectly horizontal reflecting surface; in use one measures the angular distance from a star, the sun, or even a coastal landmark, to its reflection in the mirror. Half this will be the altitude of the object, determined without reference to the horizon itself, which may be obscured by haze, etc. Condition is very fine throughout. This is one of the few known instruments produced by a member of the Simms family of nautical and mathematical instrument makers. Made prior to William (II)¹s partnership with Edward Troughton beginning in 1826, it is the only example of this unusual design we have come across. (8220) $4500.

LARGE ELEGANT PARALLEL RULE, English, c. 1800, hand-engraved on the reverse "J. Watkins, Charing Crofs, London." This all brass rule is 12" (30 cm) wide, constructed with a massive scissor hinge elegantly shaped and pierced, designed with opposing slots which provide an offsetting parallel motion as the rule is opened. There are two small knobs for grasping, and both outer edges are beveled for precision in course marking and chart reading. Condition is good noting some stains and darkening, and minor nicks.

This is a fine example of an important tool of the early navigator. Jeremiah Watkins was a successor to the well-known Francis Watkins, and is recorded as working under his own name 1798 - 1810. He in turn was followed by Watkins & Hill, who were succeeded in the mid-19th century by Elliott Brothers, and then by English Electric in 1966. Jeremiah was thus an important early link in the two-century history of this succession of quality, innovative instrument manufacturies. $2400.

GOLD SCALE SEXTANT BY CARY, English, c. late 19th century, #3271. This elegant sextant is Cary's "partial double frame" design and has a splendid inset scale of gold, divided every ten arcminutes, with a silver vernier reading to ten arcseconds. The instrument has Reeves' endless tangent screw (an 1882 patent), the governmental broad arrow mark, the Hydrographic Office mark, and the repair mark of Cooke, Troughton & Simms. The scale radius is 8"; the overall height 10-1/2" (27 cm). The sextant is equipped with one telescope, four index filters, two horizon filters, scale magnifier, scale diffuser, index arm spirit level, and fine adjustment for horizon mirror. There is no case. Condition is fine, noting a couple of small dents.

This is a good example of the rigid but lightweight innovative design by the firm founded in the 18th century by William Cary. Special features here include the quick-release index arm clamp coupled with long tangent screw fine motion with precision readout, and the unusual little spirit level on the index arm, useful when the horizon is obscured or elevated. This sextant must have an interesting history, with its governmental service and documented 20th century repair. A very rare example of the top of the line gold scale on a navigational instrument. (9235) $3950.

FINE ENGLISH SPYGLASS, c. early 20th century, signed "Ross, London, No. 26235; Made for J. Gieve & Sons, Portsmouth." Opening from 17-1/2" to 25" (44 - 63 cm) by single drawtube and objective shade, the telescope has nickel-plated brass construction, with stitched leather binding to the main tube. It is complete with achromatic doublet objective, erecting eyepiece system, dust cover and dust slide. Condition is very fine giving fine images. The retailers had premises on High St. in Portsmouth, and are known for naval swords as well. (7246) $750.

FLAT DRUM SEXTANT, English, c. first half 19th century, constructed of brass, 4-1/4" (11 cm) in diameter and 1-5/8" (3.6 cm) thick, the interior with "wriggle-work" designs and fine clear lacquer finish, the exterior of chemically darkened brass. A geared index arm carries an internal mirror, and is set with a silver vernier divided to one arc-minute. This reads against the 0° - 122° inset silver scale. There is a scale magnifier on long arm, and separately insertable dark red index and horizon filters. The sextant cover can be screwed onto the opposite side to serve as handgrip, and to avoid loss. The instrument itself is quite handsome, and fully functional, but we note a crack and chips to the cover¹s threads, and some edge damage to the sextant surround. The interior lacquer finish is excellent, the exterior rubbed and worn.

This is an unusual form of pocket "box" sextant, considerably larger in diameter than most, and yet no thicker. It is similar to that described and illustrated in Adams'/Jones' Geometrical and Graphical Essays of the late 18th century (although here with interior rather than exterior rack work). For an Adams example see Tesseract Catalogue 38 Item 55. (9200) $1450.

A MINIATURE SOLID SILVER OCTANT, English, 1979, fully hallmarked for London sterling silver of 1979, and with maker's mark. The flat frame measures 5" (13 cm) tall. This diminutive, more-or-less functional "replica" of an 18th century octant has a peepsight, horizon mirror, hinged filter, and index mirror on moving arm. The scale is divided in zenith distance every degree from 90° to 0°, with transversal interpolation, and with readout against the index arm's line of faith which is sub-divided every 10 arcminutes. The arms display floral decor, and the center presents an unusual fish or sea monster. Quality is modest; condition is very fine. Although hardly an antique, at just over 30 years of age, this is nevertheless an amusing, solid silver honestly hallmarked piece which can demonstrate the principles of celestial altitude measurement and transversal interpolation. (9275) $595.

ARTIFICIAL HORIZON OUTFIT, English, c. 1900, contained in the original 8" x 4-1/2" x 1-3/4" (20 x 11 x 4 cm) fitted mahogany case, signed "Stanley, Great Turnstile, Holborn, London." The finely made brass cell, finished in beautifully contrasting chemically darkened and clear lacquered finishes, contains a flat dark glass and is mounted with three leveling screws. Also provided is a tubular glass spirit level, one side ground flat. Condition is excellent. With the spirit level set on the black glass plate, one levels the instrument very precisely by adjusting the three screws while repeatedly turning the level by 90°. Then with a sextant, for example, one can measure the angular altitude of a celestial body by measuring the angle between the body and its reflection in the mirror, and dividing the result by two. No knowledge or view of the horizon is required, an exceptional advantage when the horizon is obscured by low fog or haze, or mountains, etc. (9222) $795.

SIGNIFICANT PRESENTATION TELESCOPE IN SHEFFIELD SILVER, English, early 19th century, stamped on the first two drawtubes "Berge, London late Ramsden," and engraved around the objective mount "de M. Berge à M¹r. Emery dit hermély, 1822." The telescope opens from 7" to 20-3/4" (18 to 53 cm) with a mahogany maintube and three drawtubes and mounts of heavy silver over copper. It is fitted with a greenish triplet achromatic objective and erecting optical system giving fine images. Condition is very fine noting the eye cap replaced.

This telescope records an interesting history, having been made by Ramsden¹s successor, Matthew Berge, and presented to the famous Jean Marie Emery dit Herméley (1769 - 1850). The sailor and later lieutenant Emery (who went by the name Herméley) served under Georges Cadoudal in the underground chouanne army, as a Royalist, against the French Revolution. (9255) $2800.

A SCOTTISH BOX SEXTANT WITH TANGENT SCREW FINE ADJUSTMENT, c. 1830, signed "Ramage, Aberdeen." The 3" (7.6 cm) diameter brass drum-shaped sextant has a removable cover that screws onto the back as handle. The finely crafted miniature sextant itself has inlaid silver scale and one-arcminute silver vernier, scale magnifier, swinging index arm and mirror with the most unusual feature of clamp and long tangent screw fine adjustment, insertable red and green filters, optional peephole or single drawtube telescope with screw-on solar filter, and mirror adjusting tool. Condition is very fine with original stitched leather outer case, noting case and cover with some wear. The sextant itself is beautiful with its original bright lacquer finish.

This is a fine example of the "snuff box" sextant, useful for exploration on land, navigation at sea especially on small craft or lifeboats, etc. But it is very special for having a precision long-screw fine adjustment to the index arm position. We know of another such instrument, in the National Maritime Museum, that with the same sort of raised quadrantal clamp plate, pierced with three holes, but signed "Adie, Edinburgh." (9191) $1450.