ELEGANT IVORY-BOUND OPERA GLASSES, French, 19th century, signed around each eye lens "Par Brevet d'Invention et de Perfectionnement." Measuring 4" (10 cm) wide overall, these elegant low power binoculars are made of gilt brass with main tubes bound in splendid turned ivory rings. There is center-focus, and a swiveling ivory handle. Condition is fine noting that each ivory ring has a single age check, formed as the ivory shrank on the brass. (7047) $550.

GERMAN PERPETUAL CALENDAR, 18th century, made of gilt and silvered brass, 1-7/8" (4.7 cm) in diameter. On one side the rotatable "Calendarium Perpetuum" shows the days of the week (in German, and marked with their planetary signs) against days of the month, and has floral patterns hand-engraved in the open spaces. The other side gives, in seven readout windows defined by its rotatable disk, month of the year with its number of days, tabulation of the important saints' and feast days in the month, sun¹s Zodiacal position, length of day, length of night, time of sun rise, and time of sunset. There is further floral engraving, as well as inclusion of a seated person amongst the vines. The Zodiacal signs are identified by amusing little hand engravings. A good example in very fine condition. (7037) $2400.

FASCINATING EARLY QUADRANT, English, mid-17th century. This very thin brass quadrant is 3-3/4" (9.5 cm) in radius, hand engraved on one side, with practice engraving of several numerals and letters on the reverse. There is a circumferential quadrant scale divided every degree, for use in measuring the angular altitude of sun, moon, stars, mountains, buildings, etc., by sighting along the edge and reading against a little plumb line which would be suspended from the apex. Next is a calendrical scale, laid out for a vernal equinox of approximately 11 March (consistent with the Julian calendar), and for a latitude of 52° (close to that of London). The sky grid of arcuate hour and azimuth lines is crossed by the ecliptic, and is consistent with Edmund Gunter¹s design of 1623. There is an edge scale of solar declination, and in the corner a fascinating shadow square, each leg divided every 5 from 0 to 50. Within the square is a scale hitherto unknown to us on surviving quadrants. The 90° angle is divided radially into ten equal segments labeled "J, F, M, A, M, D, N, O, S, A," and with "J, J" on the center line. And concentric arcs indeed carry variously the numbers 28, 30, and 31, which all align, rather primitively, with the letters, giving an aide-mémoire for the number of days in each month. The apex of the square has hand-engraved decoration of a very distinctive style found on some 17th and early 18th century English instruments: compare with that on a plane table rule (Tesseract Catalogue 76, Item 30) and that on a boxwood compendium attributed to Sutton (Wynter and Turner, p. 132). Condition is fair noting much old pitting to the brass, and only remnants of the little pinhole sights remaining. The instrument was reputedly purchased in Wales many decades ago, and probably suffered outdoor weathering a very long time before. Nevertheless it is a fascinating early quadrant. (7077) $4500.

EARLY SOLAR VIEWER, English, c. second half 18th century, made of turned dark hardwood, 1-1/4" (31 mm) in diameter, set with an extremely dark greenish glass filter of 0.3 inches diameter clear aperture (the glass held in place with a brass spring ring as used on 18th c. simple microscopes and telescopes). This uncommon astronomical implement is in excellent condition. Designed for public use, we can speculate that it was prompted by the interest in the transits of Venus (of 1761 and 1769). To an earth-bound observer, Venus would appear as a dark slowly moving spot on the sun's disk. Halley (1656 - 1742) had advocated observations of the timing of these transits from various locations on earth, for determining the sun's parallax, and thus the distance from Earth to the sun. Major expeditions were mounted, particularly in 1769. The previous transit had been in 1639, the next not until 1874. And no total solar eclipse was visible from England between 1724 and 1927. So we seem to have here a rare little "Transit of Venus Viewer." (9085) $395. (SOLD)

ELLIPTICAL LENS BINOCULARS, French, mid-19th century, signed in the eye mounts "Jumelle Elliptique, Brevetée S.G. D.G., Ringard Opticien, R. S't. Martin, 199, Paris," and with the maker¹s "RD" mark. Measuring 4-3/4" (12 cm) wide, and made of beautiful contrasting black enameled and gilt brass, with lens mounts and central focusing knob of hard rubber or wood, the binoculars have highly elliptical tubes fitted with singlet eye and objective lenses. Their unusual elliptical form provides the user with a field of view much wider horizontally than vertically, in a quite compact instrument. Condition is very fine noting some small chips to the mounts. The original leather case is rather rough, but has interesting fouled anchor motifs on the brass clasp.

M. Ringard, Parisian optician, crafted these rather remarkable binoculars. His techniques of cutting and centering the oval lenses is specially treated in an 1848 paper in the Bulletin de la Société d¹Encouragement pour l¹Industrie Nationale. (9043) $850.

HANDSOME POCKET GLOBE, English, 1859, signed directly in the gores "A New Terrestrial Globe, with all the discoveries to the present time, Pub. by J. Manning, 1859." This globe is an impressive 3-1/2" (9 cm) in diameter, with small iron axis pins, and set with twelve lithographed gores showing light green oceans, tan land surfaces, and some hand-colored outlining. It has a brilliant glassy varnish, typical of pocket globe construction in the second quarter 19th century (e.g., those of John Smith and of George Lane). Political divisions and geographical features are detailed, e.g., Germany is still labeled as "German States." Condition is very fine throughout, with completely stable crazing to the varnish. The globe fits well and rotates within a somewhat worn card box.

Not much is known of globe maker James Manning of London, for whom Elly Dekker (in Globes at Greenwich) gives working dates 1854 - 1863. In a sense the mid-19th century was the end of an era for pocket globe making; gone was the tradition of pocket cases lined inside with celestial cartography, and the production of table globes focused on the educational market (again see Dekker). Here we have a splendid example of a substantial mid-century pocket globe, with its evolved construction and wonderful glassy varnish. (9013) $3500.

SCOTTISH SILVER DOUBLE-DIAL PERPETUAL CALENDAR, second half 18th century, signed "Alexr. Wilson Kelso." This fine 18th century silver perpetual calendar is mounted in a turned wood frame 3-3/8" (9 cm) in overall diameter. One rotatable dial has days of the week (Sunday a sun face) alignable with days of the month to give any full month's calendar. The inner dial also has days of the week (Sunday a moon face) independently alignable, presumably as lunar calendar and tide predictor. Condition is very fine; it is housed in a later, excellent outer case.

This is a rare Scottish instrument, by a good maker working in the town of Kelso in the Scottish Borders area. He was likely the Alexander Wilson (1714 - 1786), type-founder, astronomer, surgeon, and instrument maker, who was, in 1758, in partnership with James Watt, and who was later appointed the first professor of Practical Astronomy at the University in Glasgow, and who is credited with the invention of philosophical bubbles. Wilson was friends with the 3rd Duke of Argyle, and was a founder of the Royal Society of Edinburgh. (9055) $2800.

THE "TOURISTEN-FERNSEHER," A CANE-MOUNTING OPEN-AIR TELESCOPE, German, c. 1900, comprising two quite portable lenses set in tin mounts, contained in the original 3-1/2" x 5" (9 x 13 cm) card box with instructions. Each lens holder is designed to clamp onto one¹s walking-stick, thus forming an impressive Galilean telescope with a 2" diameter objective and focal length of approximately 20". It functions well, and is in good condition, the box rough. (9035) $495.

FRENCH PERPETUAL CALENDAR, c. 1800, set in a 12" x 17-1/4" (30 x 44 cm) heavy oak surround, behind glass in an old gilt wood frame. The calendar itself is 10-1/2" x 15-1/2", of heavy card, hand decorated in ink and watercolor, with a collage of a flower (pansy?) in bloom. An ornate arch design is supported by twin columns on a faux-marble base, and is surmounted by a finial and a fine armillary sphere and globe. There are two volvelles, the outer with days of the month which can be set against a fixed scale of days of the week, this latter showing each day in French, its corresponding planetary symbol, and planet name. The inner volvelle rotates independently, and is set to the month. Relevant information is then visible in six windows: the time of sunrise (being the average for that month), time of sunset, length of day, length of night, Zodiacal sign symbol (beautifully drafted and watercolored), and list of the principal feast days. Condition is fair only, with losses and some browning in addition to the original brown wash, and the central pin or pulley replaced. Nevertheless it is an unusual, charming, and quite well-painted work of art and science. (9075) $1250.

GUNTER'S DAY / NIGHT QUADRANT WITH CONSTELLATION DISK, English, c. 1700, the brass quadrant 4-7/8" (12 cm) in radius, set with twin pinhole sight vanes and pierced with a hole for plumb line. The front is hand engraved with Edmund Gunter's full layout, as described in 1623. It is laid out for a vernal equinox of 11 March, consistent with the Julian calendar still in effect in England, and for latitude of 51°, consistent with Salisbury and Winchester, for example, in southern England. Arranged as a quarter of an astrolabe, for a fixed latitude, the quadrant shows the sky projection between equator and tropics, crossed by the ecliptic (divided with a Zodiacal scale), horizon, azimuth lines, and hour lines. There is an edge scale of solar declination, a shadow square at the apex, a calendar scale, and a quadrantal scale for observing altitudes of sun and stars. The sky positions of five bright stars are plotted along with their names (Al Peg for the Wing of Pegasus, Oc Tau for the Bull's Eye, etc.) and right ascensions. The details follow very closely those published by Gunter, with the addition of crescent decorations, typical of c. 1700, at the ends of the calendar scale.

The reverse carries a nocturnal, with fixed circular hour scale (twice-12 divided every 15 minutes), and central planispheric volvelle showing five constellations and their principal stars (45 in all). These are the traditional Ptolemaic circumpolar constellations of Ursa Major, Ursa Minor, Draco, Cepheus, and Cassiopeia, shown in geocentric view (i.e., on Earth looking outward), and surrounded by a calendar scale divided every five days. The constellation figures are depicted simply but quite distinctively. A survey of celestial maps (see in particular Warner, The Sky Explored, Celestial Cartography 1500 - 1800), shows enormous variety in design, the figures being adapted to the age and culture and technology, religious and political vogue, etc. But nowhere do we find the present imagery, until we turn to Gunter's description of the nocturnal with volvelle ("rundle") located in his Works in the section on the Use of the Sector. Condition is fine noting areas of shallow scratches.

In use one can perform many observations and calculations with the instrument. Quite simply one sights the sun through the pinholes and, using a little plumb line and bead, determines the time of day. One can predict sunrise and set, length of daylight, etc., for any date. By sighting any of the five stars one finds the time at night. The nocturnal is even simpler to use -- face North, hold the instrument vertical, rotate the volvelle until the orientation of the constellations matches that seen in the sky, and read the time against the current date. This use is described in more detail in an elusive work by William Leybourn, The Description and Use of a Portable Infrument, Vulgarly known by the Name of Gunter's Quadrant (3rd ed., 1731). A fine early instrument. (9020) $16,500.

HENRI ROBERT'S ASTRONOMICAL BALANCE, French, c. 1835, signed "henry ROBERT, horloger a Paris. invenit." The "balance" is constructed with a 20" (51 cm) long lacquered brass tube fitted to a flat brass suspension bar and two large brass chain links. When suspended, the whole can rotate about the zenith direction, and the tube can pivot in its vertical plane. The tube itself is fitted with a tiny lens and pinhole at one end, and a removable target at the other. The target is inscribed with a grid of lines identified by dot patterns, and is inclined to the optical axis, and visible through a cut in the side of the tube. Condition is fine and complete, retaining about half the original lacquer finish.

Henri Robert (1795 - 1874) was a clock-and-watch maker and prolific inventor. He worked with Breguet, establishing his own business in 1832, and became "Clockmaker to the Marine" as well as "Clockmaker to the Queen." This is his astronomical balance, by which one can determine the error in a watch or clock with high precision, simply by observing the sun (see Archives des Découvertes et des Inventions Nouvelles...pendant l¹année 1833). One suspends the balance in sunlight sometime before noon, aligns it with the sun, and, using the watch or clock in question, notes the exact times that the spot of sunlight crosses the lines on the target (as the sun ascends in elevation as it approaches the maximum at noon). One again notes the exact times that the same lines are crossed after noon. An average of the times should be 12:00:00 noon -- if not, one resets the watch by the difference. The maker / inventor offered the apparatus in two sizes, this one the larger and more accurate, giving time corrections to five seconds. This is a remarkable survival, complete even with the original suspension chain links. We are aware of only one other example of Robert's invention, that in the smaller version (Orologi e strumenti della Collezione Beltrame, 1996). (9040) $5500.

THE WATSON WINDOW TELESCOPE, English, c. 1925, signed "W. Watson & Sons Ltd., London, Window Telescope." This very large plano-convex glass lens, of 15" (38 cm) diameter and very long approximately 18' (5.5 meter) focal length, is set in a blackened steel frame with recurved handle / suspension bracket, and is complete with its fabric-covered "Sun-cap" cardboard shutter. Designed for hanging indoors against a window, it is in excellent condition throughout.

In The Strand Magazine of 1929, Watson advertises "WINDOW TELESCOPE. From your armchair you can enjoy all the distant view and passing life in a magnified form without resource to telescope or field glass." No eyepiece is used. The observer stands (or sits!) at a distance just inside the focal length, where the focused rays are still converging, and (especially if he/she has sufficient visual dexterity or is sufficiently farsighted) sees an acceptable, erect, magnified image of distant objects. Ads by Watson (the well-known microscope makers) show the lens in use in a typical Arts and Crafts setting. The lens is discussed by Fred Watson (Stargazer -- The Life and Times of the Telescope, 2004), who finds "telescopic" use of a single lens described by William Bourne in the 16th century! (8019) $2900.

HANDHELD ALTITUDE QUADRANT, probably northern European, c. late 19th century, made of golden lacquered brass, with a 12" (30cm) long sighting tube, 6-3/8" (16cm) scale radius quadrant below, and pendulous self-clamping index arm. Construction is simple but ingenious. The sighting tube has three interchangeable plane glass filters as "objectives" (clear, medium green, and quite dark red), each equipped with a horizontal crosswire. The quadrant is divided every half-degree from 0° to 90°, and reads altitude above the horizon. The weighted index arm swings freely, remaining vertical. When the target is sighted, one gently squeezes together the parallel arcs of the quadrant, locking the arm in place so the instrument can be lowered and the angular altitude of the object read off the scale. Instrument condition is very fine, with the original lacquer, noting some scrapes to the finish. The original fitted wood case is lined in purple cloth and covered in black paper, in good condition. This device functions as a handheld astronomical quadrant, measuring star, planet, sun, and moon positions. It may have navigational uses as well, in latitude and longitude determination, and, of course, surveying uses. An uncommon form. (9042) $1900.

ORIGINAL ROWLAND / BRASHEAR DIFFRACTION GRATING, IN GEARED MOUNTING, American, 1895, signed by hand with a diamond stylus, directly on the speculum surface "Plate prepared at the Astronomical and Physical Instrument Wrks. of Jn. A. Brashear, Allegheny, Pa., USA; AE; Ruled on Rowland's Engine, Johns Hopkins University, Baltimore, Md., USA, 1895; 14438 lines to one inch, 568+ to 1 m/m." This remarkable grating is ruled directly on a 2-1/2" (6 cm) square block of speculum metal, with a polished and ruled area 1-3/8" x 1-7/8". It is mounted vertically in a carrier which is rotatable by circular rack and pinion on a substantial base with three leveling feet, all the mounting made of handsome clear lacquered and blackened brass. A glass cover slide protects the grating, which shows some rubbing to the surface, but which produces very good spectra. Condition is very fine throughout.

Henry Augustus Rowland (1848 - 1901), an extraordinary physicist / engineer, made landmark progress in the design and manufacture of ruled gratings, his ruling engines being the best in the world for several decades. John Alfred Brashear (1840-1920) was a mechanical genius who produced numerous superb telescope objectives, and who excelled at creating extremely accurate surfaces (uniform to 1/5 of a light wave!) on speculum metal plates for Rowland's gratings.

A fine example of an original grating, this one graded "superb" by these master makers. (8057) $2400.

QUADRUPLE-EYEPIECE THREE-DRAW MONOCULAR, Austrian, early 19th century, signed "Plofsl in Wien." Opening from 3-1/4" to 8-1/4" (8 - 21 cm) and constructed of silver plated brass and copper, this small telescope is fitted with a cemented doublet achromatic objective, and a wheel of four selectable eye lenses. The tubes are rolled and soldered, not drawn. It offers upright images of high magnification but with a small field of view. Condition is fine noting negligible dents and a tiny edge chip to the lens. There is no handle or mount. The original shaped wood case is lined in purple silk and bound in red Morocco leather. Georg Simon Plossl (1794 - 1868) trained with the Voigtlander optical firm in Vienna, founding his own workshop in 1823. By 1845 he employed no less than 36 workers, and was famous for the quality of his microscopes and telescopes. (8078) $1900.

Surveying

Drafting