Demonstration

 

Complex Outfit for Frictional Testing in the Laboratory Click on any image for a larger view.

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DEELEYıS ADSORBED FILM TESTING MACHINE, English, c. 1920, signed by the maker on an interior plaque "No. 32, R.M. Deeleyıs Patent; J.H. Steward Ltd., 406 Strand, London, England," with three patent numbers c. 1918, and signed by the retailer on a case plaque "Herman A. Holz, Testing Machines of High Quality, 17 Madison Avenue, New York." Made of bright lacquered brass, this unusual instrument stands 11-3/4" (30 cm) tall on four levels separated by turned brass columns. The lowest section has gearing with two crankshafts for low and medium speed rotation of the main stage at the second level. The third level holds the mainspring, and the rotating shaft assembly which drives the dials in the glazed readout canister on top. Two blued steel pointers, which are mounted to a squiggle-worked lacquered brass gearbox, read against silvered scales of 0 (1) 100 and 0 (0.01) 1.00. There are several control knobs, for zero-adjustment rotation of the main scale, for zeroing and locking the small pointer, for engaging a train of steadying wheels, etc. The finely made 19" tall fitted mahogany carrying case has a large drawer of accessories, including four interchangeable steel stage plates, upper assembly with three stud feet and nine stackable cast-iron weights, crank handle, etc. Condition is fine noting some wear to the finish, and some rust on the iron and steel. Workmanship is of high quality throughout, and the machine has quite an intriguing "look."

Identifying this unusual device was something of a challenge for us. Despite the professional plaques, the three patent numbers may well be rogue numbers. And R. Mountford Deeley, onetime locomotive superintendent for the Midland Railway, was a bit hard to track down. But finally we have in hand the 1927 (5th) edition of Lubrication and Lubricants, by Archbutt and Deeley. Described in detail on pages 412 to 420, the machine was designed for quantitative frictional testing of lubricants, and was made by Steward in two models, the Simplex and the more sophisticated Laboratory, as offered here. In use the weighted assembly engages the spring and gearing to the pointers, but its stud feet sit freely on the lower stage plate. One applies lubricant to the stage plate, then cranks this plate slowly, and records the point at which the studded assembly slips, when the static friction of the surfaces is balanced by the strain on the spring above. It is a simple test, but a rather complex mechanical design is necessary for accurate and reliable results. We are pleased to offer this example of a rare and interesting apparatus. (and see back cover of this catalogue) (8400) $2800.

 

No Weights Needed, for the Hungarian Ducat Click on any image for a larger view.

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"WEIGHT-LESS" SELF-INDICATING DUCAT SCALE OUTFIT, German (Nuremberg), mid-18th century. This cleverly designed scale has a decoratively shaped cut steel beam 4-3/8" (11 cm) long, with suspension yoke, pointer, and integral arch cut with six tiny notches. Green silk strings support the two turned brass pans, one of which is heavier than the other (by exactly one Ducat's weight), and stamped with the coin's design, showing a figure holding an orb and scepter, and with the letters "HD" (for the Hungarian Ducat.) The original shaped wood case bears a printed instruction sheet, and a similar coin stamp to the wood. Condition is very fine and all original throughout.

In use, no weights are needed! The heavier pan should just balance the weight of a gold ducat placed in the lighter pan. For a genuine ducat, untampered with, the pointer will be vertical. If the coin has been shaved down the scale tilts and the deficiency in number of grains is automatically indicated by the notch on the arch. A fine example of this innovative form. (7394) $1950

 

The "Amsterdam Coin Scale" Outfit Click on any image for a larger view.

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PORTABLE DUTCH CORN SCALE OUTFIT, c. early 19th century. This "Amsterdam corn scale" outfit, when assembled, forms a brass cylinder 3-3/8" in diameter and 7" tall (8.5 x 18 cm). The two halves form the weighing vessels, one for corn and one for weights. The 5-1/2" long cut steel balance beam, with its brass hangers, would be connected to the vessels by chain or cord running through the guides along the sides. The original turned brass weights, of traditional mushroom form, are also present, marked 5, 10, 20, 40, and 60. Condition is fine through-out noting cleaning residue in the crevices. The "Amsterdamse korenschaal" was used to determine the specific gravity of a grain sample, as a measure of its quality. The form was apparently used only in Holland. Examples are uncommon; we find one illustrated in Kisch (Fig. 21). (7414) $950.

 

Combustion Blowpipe Click on any image for a larger view.

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FINE BLOWPIPE, possibly German, 19th century, made of clear lacquered brass, 10" (25 cm) long, with removable nozzle and turned bone mouthpiece. Very finely constructed, likely a Lingke manufacture, the blowpipe is in very fine condition. In use one blows a fine high speed stream of air into a flame, richly oxygenating the combustion and creating much higher temperatures capable of melting or vaporizing or oxidizing or reducing samples, when performing chemical and mineral analysis. (9333) $250.

 

Double Prism Polariscope Click on any image for a larger view.

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MINIATURE HAND-HELD POLARISCOPE, c. late 19th century, made of black enameled and clear lacquered brass, 2-3/8" (6 cm) overall. The frame is shaped like a tuning fork, with finger grip and twin Nicol prisms in cylindrical mounts. One places a sample (mineral thin section, or small crystal, for example) in the space between the arms and sights through the device towards a light source. The first prism passes linearly polarized light, and the second prism, which can be rotated at will, "analyzes" this light. Included are three specimens mounted between glass, one of them a series of eleven transparent strips of varying retardance, showing different colors when viewed between the crossed prisms. In fine condition, a most unusual pocket instrument. (9323) $550.

 

Captain Henry Kater's Renowned Hygrometer Click on any image for a larger view.

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HENRY KATERıS PRECISION HYGROMETER, English, c. 1825, signed "Tho's. Jones, 62 Charing Cross, London." This exquisitely crafted instrument stands 2" (5 cm) tall in its pierced cylindrical housing of golden lacquered brass. It has a highly domed glass top and pristine white enameled dial with two readouts of 0(0.01)1.00 and 0(1)10. The total range is thus 0 - 10 units, with readout divided to one-hundredth of a unit. It is fitted with golden pointers, and has step-down gearing inside. This is Captain Henry Kater's renowned hygrometer, based on the sensitive and reliable expansion and contraction, with varying humidity, of a bundle of hair or other natural material. One of the best materials was a type of grass seed Kater found in Mysore while serving with the British Army (see Middleton, 1969). The hygrometer is in excellent condition throughout, complete with its original red-Morocco-leather bound case, the case a bit scuffed.

Kater (1777 - 1835) participated in the Great Trigonometric Survey of India, returning to Britain to a life of scientific research. He invented "Kater's pendulum" which enabled measurement of the gravitational field, and developed the floating collimator. It was in the astronomical study of atmospheric refraction that he was led to the need for a sensitive hygrometer. He published an initial form in Nicholson's 1809 Journal of Natural Philosophy, Chemistry, and the Arts, arguing for its much greater sensitivity over de Saussure's design, and for its ruggedness, compactness and portability. The maker was Thomas Jones, who proudly advertised as "Pupil of the Late Mr. Ramsden." He was a very fine craftsman, responsible for many innovative details on scientific instruments (see our Tesseract Catalogue 86, a special issue on "Ramsden and His Circle"). (9313) $2950.

 

The Interference of Light "Waves" Click on any image for a larger view.

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SUPERB FRESNEL MIRRORS OUTFIT, DEMONSTRATING THE WAVE CHARACTERISTICS OF LIGHT, French, c. 1880, signed "J. & A. Duboscq à Paris." The mirror assembly, approximately 4" (10 cm) on a side, sits atop a brass pillar on a three-legged cast iron base with leveling screws; overall height varies from 14-1/2" to 21" (37 - 53 cm) by clampable drawtube. The high precision assembly holds two front-surface black glass mirrors in spring-loaded mounts, with six knobs controlling various tilts. A large micrometer wheel gives extremely fine repeatable calibrated displacement with readout on silver scales, and an adjustable shutter perpendicular to the two mirrors can block most of the direct (non-reflected) light beam. The device is constructed of blackened and clear lacquered brass, and is in exceptional near-new condition. It is stowed in the original softwood case, and exhibits the finest of 19th century construction details.

In use one reflects a single grazing light source from both mirrors simultaneously, and observes light and dark bands in the projected beam, provided there is a very slight angle between the planes of the mirrors. The banding is the direct result of interference of light, and disappears when either mirror is covered up. This experiment, devised by Augustin Jean Fresnel (1788-1827), was the experimentum crucis of the wave theory of light.

The Duboscq firm, famous for their optical instrumentation, was begun as Soleil in the early 19th century, finishing as Pellin in the early 20th. The makers Jules and nephew Albert Alexis were formally in partnership for only a few years c. 1800 (see Marcelin). A splendid example of Fresnel's mirrors. (9350) $2400.

 

Optical Demonstrations Click on any image for a larger view.

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DEMONSTRATION LENS PAIR, POSITIVE AND NEGATIVE, c. second half 19th century, made of plated brass, 3-3/4" (9.5 cm) tall with their curviform handles. One lens is double convex (positive) with a focal length of about 3-1/2"; the other lens double concave. In an exemplary demonstration, the former will magnify the printed word, the latter diminish it. An unusual pair, in excellent condition. (9340) $295.

 

Patented by Sir William Crookes Click on any image for a larger view.

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CROOKES' SPECTROSCOPE IN MINIATURE, English, c. 1875, signed "John Browning, London." This fine little spectroscope has a central trapezoidal box containing the glass prism, and two 4" (10 cm) long tubes, one with extending tube containing the two-element eyepiece, the other with extending tube containing the simple adjustable slit. Each tube can be adjusted slightly for tilt with respect to the prism. Spectra are clearly visible. The instrument is in very fine condition, with its beautiful clear lacquered finish to the brass. It possibly had been stand-mounted at one time.

This is a diminutive version of the spectroscope patented by Sir William Crookes in 1861. The large version was manufactured by Spencer Browning and Co., and was stand-mounted with horizontal collimator tube; it was exhibited at the 1862 International Exhibition. One example is in the Whipple Museum in Cambridge, a second one in the Power House Museum in Sydney. But the makers also advertised "a most efficient, portable and convenient instrument...Crookes' Pocket Spectroscope for tourists...." Spencer Browning and Co. are listed in the London directories until c. 1870, and John Browning on his own, at the same address, from c. 1872. We are aware of one other miniature example of this form. (8349) $2750.

 

 

 

 

Color Separations in Nature Click on any image for a larger view.

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SMALL POCKET SET OF CLAUDE LORRAINE FILTERS, probably English, c. mid-19th century. Mounted in a 1-1/2" (3.7 cm) long tortoiseshell framework, the three colored glass filters (yellow, orange, and blue) are useful "for producing a great variety of colors and showing their combination; it also will be found both pleasing and useful for viewing eclipses, clouds, landscapes, etc." (from 1848 Benjamin Pike, Jr. catalogue). Pike, based in New York City, imported (and manufactured) a wide variety of scientific instruments. This rare little outfit is in excellent condition (noting one small hairline crack), the filters set in exquisite multi-toned horn or tortoise mounts. (9252) $350.(SOLD)

 

Geometry in Two and Three Dimensions Click on any image for a larger view.

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"CUSACK'S PATENT GEOMETRIKON" OUTFIT, English, c. late 19th century. Contained in its original 8-3/4" x 4-3/4" x 1-1/2" (22 x 12 x 4 cm) pine box is an elaborate set of didactic materials comprising Cusack's hinged dihedral panels in mahogany and brass, plus three geometrical solids in wood, several plain two-dimensional geometrical figures, two diagrams on celluloid, numerous folding diagrams of projective geometry for mounting on the dihedral panels, numerous auxiliary planes of heavy card for placing within the diagrams, and the original long glass-headed pin. The set is essentially complete, noting slight damage to some of the paper figures. An uncommon geometrical teaching outfit in fine condition. The inventor is found in a book published in London in 1890, Cusack's Principles of Logic, by S. Blows. Professor Cusack produced a series of textbooks, all published by the City of London Book Depot, as well as the present "Set of Apparatus for Simplifying the Study of Solid Geometry, as required for Science Subject I," plus sets of drawing and shading models. (9322) $1450.

 

French Pocket Thermometer Click on any image for a larger view.

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A REAUMUR WATCH-CASE BIMETALLIC THERMOMETER, French, 19th century. The case is made of bright plated metal, 1-3/4" (44 mm) in diameter, with glazed front and removable back plate. The dial is delicately hand-painted with "Reaumur" and a -35° to +80° scale divided every degree and labeled "Glace" (i.e., "Ice") at 0°. The mechanism has a long shaped bimetallic spring, amplification linkage, and geared sector driving the pointer which is preloaded by a fine hairspring. Condition is fine and functional throughout, noting light scratches to the dial plate. This handsome pocket thermometer is unusual in being designed solely for the Reaumur temperature scale, as proposed by Rene Antoine Ferchault de Reaumur in 1731. He set the freezing point of water at 0°, and, for the "convenience" of octogesimal division, the boiling point at 80°. It was generally replaced in the late 18th century by the Centigrade system. (8279) $1600.

 

Certified Chemistry Standards Click on any image for a larger view.

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CHEMISTRY STANDARD VOLUME MEASURES, English, c. 1900, comprising a set of five graduated glass pipettes, numbered "2244," engraved variously with volumes in minims, grains, drachms and ounces, each one etched with a sequence of certifications including date and ruling monarch (e.g., 1908 ER, 1921 GR, 1931 GvR, 1941 GviR, 1951 GviR, 1961 EiiR). The fine fitted mahogany case is 12-1/4" x 3-7/8" x 1/2" (31 x 10 x 1.3 cm) and bears a brass plaque engraved "County of Renfrew, DeGrave & Co. Ltd. Makers London." In excellent condition, this is an unusual set of fine volume standards. (9272) $495.

 

Unusual Chemical Balance Click on any image for a larger view.

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SINGLE ARM BALANCE, Continental, mid-19th century. The finely grained hand-dovetailed walnut(?) case measures 9-1/4" x 5" x 3-3/8" (24 x 12 x 8 cm) , with internal fitted drawer holding the case-mounting balance outfit. There is a turned brass pillar with steel assembly supporting the steel beam with its spherical brass counterweight and adjustable side weight. A double pan hangs from the far end. This unusual balance is in very fine condition, and has an interesting note of provenance within the drawer: "Cette balance, moins les poids, appartient a Mr. Kaeppelin, profess'r." Rodolphe Kaeppelin (1810 - 1891) was science professor at the Lycee de Colmar, and wrote a text Cours de physique (4th edition 1846). Kaeppelin is best known for his innovative "hydrostat" weighing instrument, published 1856. (8415) $950.

 

Acoustic Columns Click on any image for a larger view.

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DEMONSTRATION SOUNDING TUBES, probably English, late 19th century. These four lacquered brass tubes are mounted on a mahogany base 13-1/4" x 4" (34 x 10 cm), the tallest standing 11-1/8" above the base. Each has a wood plunger piston which, when withdrawn rapidly, produces a sound whose frequency depends on the length of the standing column. Complete and all original, in fine condition. (9282) $975.

 

Provincial Standard Measure Click on any image for a larger view.

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EARLY PORTUGUESE VOLUME MEASURE, probably northern Portugal, c. early 19th century. Carved from a single block of wood, with handle, pouring spout, and overflow notches, the vessel measures 4" (10 cm) tall. Condition is fine, noting old deposits and a few worm holes. This vessel would have served as a secondary standard measure for liquids; when filled to the level of the two notches, through which any excess liquid spills away, it contains approximately 294 milliliters. The Portuguese system of volume measure for liquids (oil, wine, etc.) was standardized by King Sebastiao in 1575, and successfully continued in use until the adoption of the metric system in the 19th century. The principal unit was the almude, subdivided into twelfths (the canada) and forty-eighths (the quartilho). There were also half-units of each of these. But the actual volume of the almude remained very much a local matter; for example, in Lisbon it was the equivalent of 16.54 liters, but in Porto 25.08 liters (Doursther, 1840; Noël, 2009). So our vessel falls between the quartilho of Lisbon (345 ml) and the meio-quartilho of Porto (261 ml); it must represent one of the innumerable local volumes in use at the time. The construction is typical of vessels from northern Portugal. For more background on the subject, and for examples of primary standards, see Weights and Measures in Portugal (2007). (8369) $950.

 

Authorised by the French Government Click on any image for a larger view.

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FRENCH HANGING SCALE WITH VERTICAL COUNTERWEIGHT, c. 1870, signed "Romaines, Autorisees du Gouvernement; Lemercier, Brevete S.G.D.G.," and bearing Lemercier's mark, the verification stamp, and the number 254 (possibly for that bureau of control). This balance scale is made of iron and brass, 11" (28 cm) overall (from top of suspension ring to bottom of hook). A single horizontal shaft carries the counterweight arm, pointer, and hook arm, but the latter is suspended at a slight offset from the shaft axis, giving considerable leverage in the linkage. As a load is applied to the hook, the counterweight and pointer incline accordingly, with readout against a scale of 0 - 10 kilograms, subdivided every 100 grams. The hook arm is cleverly shaped to allow passage of the spherical weight. Condition is fine, the metal cleaned long ago. Lemercier, a clockmaker of Tinchebray in the Orne region in France, is credited with this design, and in fact held the legal rights to it, from 1863 until 1898, as granted (and eventually withdrawn) by the French bureau of weights and measures. The present example is the earliest form, datable to 1863 - 1873 (see Pommier, 2005). (8339) $1350.

 

Sphericity Measurement

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PRECISION SPHEREOMETER, French, mid-19th century. Standing 6-1/2" tall, made of brass with a steel lead screw, the spherometer has three tapered legs, central pin on the fine thread precision screw, and "micrometer" readout with vertical scale graduated every half-millimeter, and circular scale (on a six-spoked ring) graduated every 0.001 millimeter (!) The central pin presses against an upper double lever arm with very high amplification factor, so that repeatable positive contact is reliably indicated. The instrument thus measures the central height, and therefore the sphericity, of a surface. Condition is fine noting nicks around the scale edge, and crazing to the original lacquer finish. The most sophisticated early mechanical spherometer we have seen. (6401) $695.


Original Prize Medals for Photography Click on any image for a larger view.

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PHOTOGRAPHIC PRIZE MEDALS, English, 1880's. The two medals, which came to us from the same Byrne family source, are described briefly as follows:

1) Silver 1-1/2", O.D., Derby Corp. Art Gallery 1882 VR, Industrial Art Prize Medal. No inscription; wonderfully designed and super-detailed.

2) Bronze 1-3/4", one side with bust of James Watt, Royal Cornwall Polytechnic Society, First Class, edge engraved "Byrne & Co., for portraits on China, 1881."

   

The winner's name is engraved around the edge of the latter. The photographers Byrne & Co. are found in 1883 and 1900 directories at 1 Clarence Terrace, in the London Borough of Richmond upon Thames (home to Hampton Court Palace, Ham House, Kew Gardens, etc.) Condition is fine. $400./the pair

 

Early De Luc Hygrometer Click on any image for a larger view.

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HAIR HYGROMETER, English, c. second quarter 19th century, signed "Watkins & Hill, London." The open framework is constructed of clear lacquered brass, 8-3/4" (22 cm) tall overall, with suspension ring and mounts for the mechanism. It is fitted with a circular scale of relative humidity divided every unit from 0 to 100, and ends marked D(ry) and M(oist). An index pointer is driven by central double pulley, the pulley drawn counter-clockwise by string attached to a tight bundle of very fine hair, and clockwise by string attached to a long finely wound preload spring. The hair is secured, at the base of the instrument, to an adjustable calibration screw. If the air dries out, the hair shrinks, pulling on the string and rotating the index arm counterclockwise against the spring tension. Condition is very fine complete with the original shaped wood case lined in purple cloth and bound in red Morocco leather. This is a good early example of the hygrometer form designed by Jean-Andre De Luc but here activated by a fine bundle of hair rather than by a strip of whalebone. Hair was in fact the province of Horace Benedict de Saussure, and controversy between the two scientists raged for years in the late 18th century (see Middleton, 1969). (8359) $2850.
 

 

Looking around Corners in 1750 Click on any image for a larger view.

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RARE ITALIAN POLEMOSCOPE, 1750, signed on a silver band, "In Galleria D.S. M.C. 1750." Made of turned (probably tropical) wood, bound in (now quite darkened) silver, this optical instrument measures 1-13/16" (47 mm) tall by 1-7/16" (36 mm) outside diameter. It has viewing port and observation port, with internal oval glass mirror set at 45°. The other end is set with a circular plane glass mirror. Condition is fine except for considerable loss of silvering to the mirrors. In use the polemoscope, or "jealousy glass," permits very discrete viewing at right angles of, for example, patrons at the opera. This unusual example, with its simple second mirror, allows one to also view to the rear, surreptitiously, or to check one's own makeup. We have not identified the maker. The "Galleria" address suggests the shops in the fine arcades of northern Italy, for example in Milan and most notably in Turin, where the Galleria built by the famous architect Amedeo de Castellamonte in 1673 still exists, and even includes an ongoing shop established in 1707 (thanks to Alberto Lualdi for this insight). It is tempting to connect the initials with the workshop of the optical instrument maker Domenico Selva (and his son Lorenzo), quite active in mid-18th century Venice (albeit a city of arcades termed "Procuratie" and not "Galleria"). But perhaps we have here tangible evidence of an unrecorded maker. (8319) $2950.  

 

Official Pre-Metric Measure from Upper Austria Click on any image for a larger view.

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AUSTRIAN OFFICIAL STANDARD MEASURE, 1777, stamped (1)777 and with an elaborate crowned double eagle and with twin cross-hatched punches, engraved "Iohan Ferdinand Pachner, K=K, Stadrichter, 1780," and stamped with a recertification "(1)859, Wien" and a small double eagle. The cylindrical brass vessel measures 3-1/16" (8 cm) tall by 2-5/16" (6 cm) base diameter, with shaped base and lip, and decorative turned rings. Condition is fine. This unusual vessel is an official standard for liquid measure, with a capacity of 1/4 Seitel, the Seitel, at about 0.354 liter, being 1/4 of the Mass, the principal pre-metric volume measure in Austria. It was made in 1777 for the important old town of Steyr, in Upper Austria, where Johann Pachner served as city judge from 1772 to 1781, then as mayor from 1782 to 1786. (8399) $3250.
 

 

Rare Certification Rule for Standard Measures Click on any image for a larger view.

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RARE VOLUMETRIC MEASURE STANDARD RULE, French, early 19th century, signed "Kutsch a Paris". The 13-3/4" (35 cm) long brass rule has seven leveling stubs aligned with "Diametre et hauteur des Mesures Usuelles a Grains" ranging from "1/8 Liter" to "Double Boisseau." The other side is divided with two scales (heights and diameters) for "Mesures Usuelles pour les Liquides" from 1/16 to 1/4 liters. Condition is very fine noting light wear. This standard rule served to certify the heights and diameters of the cylindrical measures used to measure out verified quantities of volume. For grain measures, the cylinders had equal heights and diameters; for liquid measures, the height was twice the diameter. The revolutionary bodies in late 18th century France required the best craftsmen to implement this standardization of weights and measures. Lenoir, Fortin, and Jecker were commissioned. Kutsch himself was employed by the Commission des Poids et Mesures, according to Daumas, and was called upon to make measuring comparators. He is listed in Paris directories from 1803 to 1828, at various addresses, as a mathematical instrument maker specializing in weights, measures, and balances. We have had one other standard rule by Kutsch (Tesseract Catalogue 59, Item 47), and the CNAM in Paris holds a standard meter by him. Rare and significant. (8335) $2950.

 

The "Kilogram Divided" Click on any image for a larger view.

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OFFICIAL FRENCH STANDARD WEIGHTS -- THE "PARALLELOPIPED KILOGRAM", very early 19th century. Contained in its 4" x 4-1/2" x 1-1/8" (10 x 11 x 3 cm) fitted wood box are the subdivided elements of a kilogram, specifically brass weights of 500, 200, 100, 50, 20, 10, and 1 gram. Each rectangular weight has an adjustment plug, and is marked with its weight value, plus a host of standardization marks, including variously an image of a balance beam, the number 47, the city (Limoges), the "all-seeing-eye" above an "L," the letter "H," a crowned eagle, and letter certifications running continuously (except no "J") from A through K. Condition is very fine and complete but for tweezers and a few of the smallest weights (present are 991 out of the full 1000 grams). The "parallelopiped kilogram" was published by chemist Claude Antoine Prieur in 1797, in the Annales de Chimie. He devotes eight pages to their description and advantages, and recommends those made by Fortin. The weights could be purchased at the Bureau of Weights and Measures, on rue Dominique in Paris. The present set was made for official use in the town of Limoges, and bears certifications through the first quarter of the 18th century. Following Pommier (in recent issues of Le Systeme metrique), we find that for primary standards the balance beam mark was used 1801 - 1840, the crowned eagle 1808 - 1812, and the sequential year letters starting with A for 1802 (or a couple of years later in some of the provinces). A very rare survival, this is an important standard set from the early years of the metric system. (8379) $3800.

 

Massive Demonstration Outfit Click on any image for a larger view.

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ELABORATE GYROSCOPE COMPENDIUM, probably German, c. 1900. This massive outfit includes an iron base, iron mounting ring 11-1/8" (28 cm) in outside diameter, brass rotor, brass rotor in double gimbal rings, twin rotors in iron ring, speed crank assembly, mounting arms, and seven stackable brass weights. Total weight of the outfit is approximately 45 pounds. Condition is fine and seemingly complete, noting some mild surface rust and a couple of little screws lacking at lubrication(?) holes. Components may be assembled in three basic ways (see photos): (1) iron base with ring and, on top, the arm mounted with rotors at each end and weights in the middle; (2) iron base with vertical ring and central rotor; (3) iron base with mounting block, brass rotor, and spinning wheel with handle. A remarkable compendium. (8387) $4500.


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