Telling Time by the Stars Click on any image for a larger view.

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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.


High Precision Time Setting Click on any image for a larger view.

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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 Gearing of the Planets Click on any image for a larger view.

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MECHANICAL ORRERY FOR LANTERN PROJECTION, English, mid-19th century. The mahogany panel measures 7" x 4-3/8" x 1/2" (18 x 11 x 1 cm) with a central 3-1/2" hole mounted with eight brass ring gears carrying representations of all the planets and their moons (out through Neptune), these moving planets painted in color on glass. The gears are driven by a brass and steel crank with a turned wood handle. The result is a planar view of the solar system, with the planets circling the sun at variable rates. Condition is very fine and functional throughout, with a little old repair to the crank. Notably Mars' orbit includes seven asteroids; Jupiter has cloud bands or rings; Saturn has rings and eight satellites; Uranus has six satellites, and Neptune is depicted with two satellites and rings! (9062) $950.


Astronomical Quadrant with Rackwork Motions Click on any image for a larger view.

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JONES' IMPROVED ASTRONOMICAL QUADRANT, English, early 19th century, signed "W. & S. Jones, 30 Holborn, London." This handsome lacquered brass instrument stands 10" (25 cm) tall on its tabletop base with three leveling screws. The base has a circumferential degree scale, and is centered by a rotating disk which carries the instrument on central pillar, and which is fitted with crossed spirit levels, internal pinion and ring gears, and one-arcminute vernier. Atop the openwork pillar is mounted the 4-1/4" (11 cm) radius openwork quadrant with 0° - 90° scale, one-arcminute vernier, and pinion with external rack. Thus the instrument functions as a geared altazimuth theodolite. It is aligned not with sight vanes but with a right angle telescope with sliding focus to both the objective and eyepiece, fitted with solar filter. Condition is very fine, complete, and functional; the brass is spotted but retains most of its original clear lacquer finish. This is a very rare example of Jones' improved astronomical quadrant. In his Lectures of Natural and Experimental Philosophy George Adams (and subsequently William Jones) devotes six pages to the construction and use of the simple astronomical quadrant. But in a footnote, Jones describes this improved version: "By the addition of a small telescope, with a reflecting eye-piece, vernier scales to the arc and circle, rack-work and pinion to the arc AB, and circle EF, &c. I have rendered this small instrument useful for observing angles up to the zenith, and with more ease and accuracy for angles in general." The first example we have seen. (9011) $9800.


Aluminum from the Columbian Exhibition Click on any image for a larger view.

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PERPETUAL CALENDAR MADE FOR THE COLUMBIAN EXHIBITION, American, 1892, signed "Perpetual Calendar, Patd. 1891 & 1892 by W.W. Kitchen." Made of aluminum, 1-3/16" (3 cm) in diameter, the disk bears on one side a raised profile of Christopher Columbus, and on the other a calendar marking every seventh day of each month. At the center is inset a brass volvelle with the days of the week. Setting this volvelle once per year allows direct readout of the day of the week for every date. This is a fine example of the perpetual calendar patented by William Whitney Kitchen, of Rockford, Illinois, on 1 December 1891. It was available at the 1893 World¹s Columbian Exposition held in Chicago to celebrate the quatercentenary of Columbus' 1492 voyage to the New World. (9052) $450.


Triplet Lenses Throughout Click on any image for a larger view.

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REMARKABLE COMPACT ALL-TRIPLE-LENS BINOCULARS, French, c. 1875, engraved "Douze Verres" (for "Twelve Lenses") and signed in the case "Gregoire Opticien, Quai St. Antoine, 14." Measuring 3-7/8" (10 cm) overall and 1-1/8" (3 cm) thick (closed), they are constructed of gilt brass and tortoiseshell, with a central knurled ivory focusing knob. Each objective lens, and each eyepiece, is itself a triplet, a sophisticated design to minimize aberrations and permit a compact, short-focal-length instrument. The apparent maker was Gregoire of Lyon, working throughout the third quarter 19th century. The firm had been founded in 1790, owned by Pierre Biette in the 1830's, and by H. Peter in the late 19th century. A fine device, in superb condition, with the original carrying case. (9030) $1350.


A Single-Lens Telescope Click on any image for a larger view.

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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.













Astronomical-Navigational-Surveying Quadrant Click on any image for a larger view.

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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.


Lunar / Solar Calendar Disk Click on any image for a larger view.

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PERPETUAL CALENDAR / LUNAR CALENDAR, English, 19th century, made of brass 1-1/2" (3.7 cm) in diameter. One side has a rotating disk marked "Day of the Month For Ever," with a smiling sunface and a ring of month dates. This reads against a fixed ring of weekdays. The other side has a volvelle marked "Moon's Age, Phases, and Southings," with circular scales of twice-12 hours, date of the lunar month, and weekdays. An eccentric circle indicates fullness of the moon. In fine condition, this is an uncommon form of lunar / solar calendar. We note a variant version, undoubtedly by the same maker, marked as a tidal calendar "High Water and Moon¹s Age" (Tesseract Catalogue 38, item 58). (8088) $750.


Innovative Telescope in Silver Plate Click on any image for a larger view.

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SPLENDID MINIATURE TELESCOPE WITH COMBINABLE EYE LENSES AND SOLAR CAP, English, c. last quarter 18th century, signed "J. Bleuler, London." Constructed with tubes and fittings of Sheffield silver plated copper and brass, this little telescope opens from 2-3/4" to 6" (7 - 15 cm) with three drawtubes. The main tube is finished with black enamel over copper. Giving erect images, the optics are a greenish triplet achromatic objective, two swiveling eyelenses useable singly or in combination, and a slip-on solar filter / dust cap. It is signed on the largest drawtube, and numbered 1, 2, 3 on the smallest. Condition is very fine noting a few scratches to the enamel. It is complete with the original cylindrical wood carrying case bound in red Morocco leather. The innovative maker of this unusual telescope was John Bleuler (1757 - 1829) of Ludgate Hill, apprenticed to Shuttleworth, made free in the Spectaclemakers Company in 1779. (8028) $2200.


Carl Zeiss circa 1930 Click on any image for a larger view.

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OFFICIAL CARL ZEISS PLANETARIUM PHOTOGRAPHS, German, c. 1930, the 14 original silver print photographs measuring 5" x 7" (13 x 18 cm), and variously bearing "Carl Zeiss, Jena" stamps, code number stamps, and/or applied printed descriptions. Depicted are planetaria, equipment, and activities. Most sites are in Germany; there are dramatic views of the powerful modernist architecture of the Weimar Republic applied to planetarium buildings. One unforgettable image shows Mussolini departing the Mailand (Milan) "Ulrico Hoepli" planetarium at its dedication on 20 May 1930. (8038) $1150.


"The Optical Paradox" Click on any image for a larger view.

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THE DIVIDED TELESCOPE -- AN OPTICAL ILLUSION, probably Austrian, c. late 19th century. Lacquered brass sighting tubes, with plain glass "lenses", are mounted through rectangular wood pillars, on a steel column and cast iron base. An air gap is present between the two ends of the "telescope". An observer sees very clearly through the instrument, even when an opaque obstacle is placed in the air gap! A sliding wood panel reveals the secret -- a sequence of four plane mirrors which direct the light down, across, and back up to the viewer. Overall dimensions are 12-1/2" x 15-1/4" x 2-1/2" (32 x 39 x 6 cm), and condition is fine. George Adams terms this "The Optical Paradox, or Double Perspective." A similar device is illustrated by G. L'E. Turner in Nineteenth Century Scientific Instruments (1983), along with an engraving by Tissandier showing such a telescope in use, the observer looking directly through a massive stone! A simple device, but quite uncommon, this the first example we have seen on the market. (8018) $2700.


Handheld Reflecting Telescope, in Fishskin Case Click on any image for a larger view.

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MINIATURE GREGORIAN TELESCOPE, English, c. third quarter 18th century. Measuring 7-1/4" (18 cm) overall, complete with turned brass end cap, the instrument has bright speculum metal mirrors, two-element erecting eyepiece system, and external screw focussing to the secondary mirror. Craftsmanship is excellent, and it gives superb images even in daytime. The telescope is contained in its wonderful original shaped case of wood lined with green velvet and covered in black fishskin. Condition is very fine throughout, noting a bit of rubbing to the original lacquer finish on the brass, and loss of one small semicircular end to the case. The miniature Gregorian telescope is known in very few examples; we have had one by Stedman of London (Tesseract Catalogue 52 Item 7), and one unsigned (Catalogue 40 Item 6). A splendid example. (8013) $4950.



Important American Diamond-Ruled Grating Click on any image for a larger view.

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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.


Uncommon Globes from Chicago Click on any image for a larger view.

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AN AMERICAN GLOBE PAIR, c. 1910, each 10" (25 cm) diameter globe signed "Atlas School Supply Co., Chicago, Manufacturers of Globes." The terrestrial gores are color lithographed and dense with detail, and include isothermal lines, important undersea cables, and wireless communications. The celestial gores are printed in blue, with numerous stars with their astronomical letter and number identifications, and with the traditional constellation figures finely printed in pale bronze. Each globe is mounted in a bent wire semi-meridian, which is inserted into an 11-1/2" (29 cm) tall turned wood base with applied distinctive decor of winged torches (?) and sunflowers (?), gold painted throughout. Condition is good noting some browning to the paper, a couple of small scratches, and some flaking to the gold. Possibly of Masonic provenance, an interesting American globe pair. (7029) $2200.


Four-Eyepiece Telescope by Plossl Click on any image for a larger view.

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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.



Prague-Centered Projection with Celestial Volvelle Click on any image for a larger view.

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THE URANOSCOPE OF PROFESSOR ADOLF MACH, Czech, c. early 20th century, signed "Uranoskop. Astronomicko-zemepisny ukazatel. Sestavil prof. Adolf Mach." Constructed on heavy card, 18-5/8" x 19-3/4" (47 x 50 cm), this unusual planisphere has a rotating volvelle of the heavens printed on starched linen, and a rotating brass index pointer, with readout against an outer hour scale divided every minute. Underneath the volvelle is a fixed map of the earth, printed in colors, utilizing a most remarkable projection centered on Prague. Condition is good with general light soiling and wear, and wrinkling to the linen. (8048) $950.


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