Thursday, 23 April 2009

John Benjamin Dancer and the Large Hadron Collider

Photos courtesy of G P Matthews
What has John Benjamin Dancer got to do with the Large Hadron Collider. Absolutely nothing, except it makes for a catchy headline and also the fact that the LHC is undoubtedly the largest scientific instrument ever made, and the microphotographs of JBD are probably amongst the smallest objects to be seen at the 46th International Scientific Instrument Fair, to be held this Sunday, 26 April at the Thistle Marble Arch Hotel . Dancer was born in London in 1812, to a family of scientific instrument makers, and at 23, inherited the family business. He was involved with photography shortly after its invention in 1839. In 1841 he moved to Manchester where he remained for the rest of his life. He published a large series of microphotographs in the 1850s, 277 of which can be studied in the exhaustively researched history by Brian Bracegirdle and James B. McCormick, The Microscopic Photographs of J. B. Dancer. The subjects range from Sturgeon's Tablet in Kirby Lonsdale Church, containing 750 letters, the whole memorial reduced from 4ft to 2mm, to eminent figures in science such as Faraday, and Herschel, as well as poetry, Shakespeare, architecture, paintings and much more. According to the Manchester Microscopical and Natural History Society, Dancer was responsible for the first sending of microfilmed images during wartime, in the 1870s, during the Franco-Prussian War. He was posthumously awarded a Medal of Meritorious Service by the National Microfilm Association of the USA in 1960.
Graham Marsh, exhibitor at the Fair, has a database of instruments made by Dancer, at his Virtual Museum.

Thursday, 9 April 2009

Laennec. Provenance and Gandhi's Sandals

Nearly two thousand four hundred years ago Plato said "necessity is the mother of Invention" The act of listening to body sounds for diagnostic purposes has its origin further back in history, possibly as early as Ancient Egypt.Rene Theosophilus Hyacinthe Laennec learned as a child that sound travels through solid materials, a fact that had probably been known for quite some considerable time. Often its the case that an invention has to wait for the relevant technology to be in place, but why did it take until 1816 for somebody to roll up twenty four sheets of paper as a tube to listen to chest sounds? Many doctors before had placed their ear to the chest of their patient to listen for sounds to aid their diagnosis and surely Laennec was not the first to be embarrassed in this situation.
Laennec was an experienced wood turner and produced a number of stethoscopes, slightly changing the length and the design in the process. The Science Museum, London, has one of these in their collection, with a paper label glued on the outside, giving its provenance, (image no. 10322024). How many more were made by Laennec is not known, as they were not signed.However, one original Laennec stethoscope was purchased in 1991 by Doctors Yola and David Coffeen from Tesseract. This stethoscope has a wonderful provenance, taking it from 1819 to the present day, as the following entry from the Tesseract catalogue reveals:

The stethoscope is contained in a fine late 19th century case, affixed with a silver plaque beautifully engraved with the declaration that Laennec, who had had training as a wood turner, made this instrument himself, and with the provenance of ownership -- "STÉTOSCOPE (sic) tourné par LAENNEC offert par lui au Professeur LOBSTEIN de STRASBOURG qui le laissa à HIRTZ qui à son tour le donna au Professeur STRAUS." (Translation: Stethoscope turned by Laennec and offered by him to Professor Lobstein in Strasbourg who left it to Hirtz who in his turn gave it to Professor Straus.) Visible in ink on the stethoscope itself is the signature "Lobstein" with traces of additional writing (Note: Under ultraviolet light this inscription is more distinct, but still incomplete. It includes the word "stethoscope" written twice.) A handwritten letter from Louis Pasteur's grandson, Prof. Pasteur Valléry-Radot, dated 10 July 1966, accompanies the instrument, declaring: "Ce stéthoscope de Laënnec a été entre les mains de Lobstein, de Hirtz, de Straus et de Grancher. Il m'a été donné par mon parrain le Professeur Grancher, en 1905. Je l'ai gardé jusqu'à aujourd'hui. Paris, le 10 juillet 1966." (Translation: This stethoscope of Laennec was in the hands of Lobstein, of Hirtz, of Straus, and of Grancher. It was given to me by my godfather, Prof. Grancher in 1905. I have kept it until today. Paris, July 10, l966.)

Thus, the stethoscope was given by LAENNEC to his friend Prof. JEAN-FREDERIC LOBSTEIN, le jeune (1777-1835, Director of the museum of the School of Medicine in Strasbourg in 1819, at the same time named to the Chair of Pathological Anatomy, and author of a number of articles on pathological anatomy which supplemented articles written by Laennec), who gave it to MARC-MATHIEU HIRTZ (1809-1878, Head of the Clinic at the Medical School in Strasbourg, professor of pathological and clinical medicine, member of the Academy of Medicine -- named in 1873), who in turn gave it to ISIDORE STRAUS (1845-1888, who was "Agrégé" at the School of Medicine in Strasbourg, when the German invasion of Alsace forced him to flee to Paris, where he worked with Chamberland in Pasteur's laboratory. He was an open partisan of Pasteur's theories. In 1883, he was part of an expedition to Egypt which was sent to combat an epidemic of cholera). The stethoscope was passed on to JACQUES-JOSEPH GRANCHER (1843-1907, who was known from very early in his career for his work in percussion and auscultation. He later became clinical professor of pediatrics, and was instrumental in early childhood vaccinating based on Pasteur's work.) He was the godfather of LOUIS PASTEUR VALLÉRY-RADOT from the latter's baptism on May 13, 1886. Valléry-Radot (1886-1970) was the son of René Valléry-Radot and Marie-Louise Pasteur, fourth child of Louis Pasteur. He himself was a prominent physician and writer, and member of the Académie Française. Grancher gave the instrument to his godson, who sold it privately in 1966.

Provenance, when it can be assigned without any uncertainty, is a tremendous plus for enhancing the value of a scientific instrument, especially when it is from the owner and inventor of the piece. Unfortunately very few instruments come on the market with undisputed provenance, a paper label or even an engraved inscription can still be very effectively faked, but the power of celebrity ownership was shown a few weeks ago, when three objects owned by Mahatma Gandhi, a cheap watch, a pair of sandals and a brass bowl fetched £1.4 million at Antiquorum, in New York.

We'd like to hear from any exhibitor at the Scientific Fair who will be bringing an instrument to sell with an interesting provenance.

Wednesday, 8 April 2009

See both halves of Babbage's brain in one day

For the fair visitor who arrives in London before 26 April or staying on after for a city break, here's a few suggestions for places to visit. For the medical collector a trip to the Hunterian Museum at the Royal College of Surgeons, in Lincoln's Inn Fields, not many instruments but lots of body parts in jars, as well as half of Charles Babbage's brain. The other half is on the first floor of the Science Museum near to his Difference engine.The Science Museum continues to dumb down, as more and more of its permanent collection finds its way into the Blyth Road Store, although their slide rules, calculators and drawing instruments are fairly impressive. The Wellcome Museum on Euston Road has two temporary exhibitions, both about mental illness: Bobby Baker's Diary Drawings, Mental Illness and me 1997-2008 and Madness and Modernity, Mental Illness and the Visual Arts in Vienna in 1900. Well worth a visit is the permanent exhibition "Medecine Man." The best collection of surgical instruments is still on the top floor of the Science Museum. The new Clocks and Watches Gallery at the British Museum has some very interesting scientific instruments, including "the most sophisticated astronomical compendium known to have survived.." Made by Johann Anton Linden it contains numerous types of gilded and silvered brass components, including sundials and calendrical tables.It also has a table of latitudes and a table for converting time in different systems of hours, as well as an astrolabe.

515 Leeuwenhoek microscopes still not accounted for.

I was at Christies Auction room in South Ken today and watched the Leeuwenhoek microscope sell for a staggering £313,250. It was found in box of laboratory impedimenta from the zoological department of Leiden and purchased by the present owner. The catalogue description goes on to say that of the over 550 microscopes made only nine are known to be extant.He gifted 26 silver examples, now worth just over £8million, to the Royal Institution, who it would appear have managed to lose the whole lot! It might be worth them looking through their own boxes of laboratory impedimenta to see if they can find them. Anyway that still leaves over 515 for the rest of us to find.Good hunting!

Saturday, 14 March 2009

How much research is enough?

We at Tesseract pride ourselves on finding arcane objets of science and medicine, and on researching them thoroughly. But we feel our research is always incomplete; rarely can we even answer of the journalist's six basic questions: "WHO, WHAT, WHEN, WHERE, WHY, and HOW".

Here we present two examples, and would welcome further insight. We have in stock a monocular of truly exceptional quality, certainly 18th century, and probably English, based on the casework with its scalloped silver trim, etc. But WHO made it and WHERE? Perhaps the leather stampings can be identified, or the style of engraving on the mother-of-pearl. Many analyses could be done, from the origin and species of the rayskin, to impurity content of the silver, to microarcheological studies of pollen grains, etc., caught as dust in little crevices. Where does / should / must one stop?

Secondly we have a fascinating level, described as follows:
SIXTEENTH CENTURY LEVEL, PROBABLY FOR GUNNERY, Continental, signed “A. Pourtales, 1588.” The level is of sturdy brass, 7-5/8” (19.5 cm) wide from foot to foot, and over 1/4” (7 mm) thick. An integral 90° arc is divided every degree 0° ± 45° and labeled every 5°. There are distinctive early numeral shapes, in particular the z-shaped “2” and the slanted topless “5.” The vertex is pierced for use with string and plumb bob. The arms are decorated with sinuous floral designs, engraved and punched. Surfaces have linear outlines throughout, and there seem to be small traces of gilding. The reverse is otherwise plain but for a preliminary scale division on the arc. Condition is good, the brass with a fine dark patina, noting nicks and a stress crack in the arc.
This is a splendid example of early level, probably made for setting elevation (or depression) of a cannon . Bion (1709) shows a similar level on the breech of a cannon, and various forms of gunner's level are illustrated by Bennett & Johnston (The Geometry of War, 1500 - 1750).
The year 1588 is significant, signalling the defeat of the Spanish Armada (with its invasion fleet of 130 ships!) by the British. It is difficult to pin down the maker; the name “Pourtales” itself is widespread. In one name search, for example, we find a Count Albert Pourtales exploring the Wild West in the early 19th century. He was born in Paris, but a descendent of Huguenot refugees who had emigrated to Neufchatel (Prussia, now Switzerland) in 1720. His father served in the Prussian army, then for Napoleon, and finally for the Berlin court. The numeral shapes are another small clue to origin, the “2” form suggestive of a German origin. But more research needs to be done.

So we know WHEN and by WHOM it was crafted, but WHERE was it made, and for WHAT exact purpose? And how do we even approach these questions? Such mysteries, in fact, are the real fascination of our business.

Wednesday, 11 March 2009

The exchange rate is looking good!

The exchange rate is looking pretty good at the moment for our colleagues in the USA who are thinking of coming over for the fair in April, in fact, almost the best its been since records began, except for almost parity in 1985. I can remember almost selling out of stock at this time but when I went to replace it I suddenly found all the prices had gone up! Some time in the early twentieth century W. F. Stanley produced “Higgins Patent Calculating Triangle”. The exchange rate only seems to go from 4.80$ to 4.90$ so I guess that puts it in the first quarter of the twentieth century. I googled the calculator to see if I could find out more only to discover one appearing at auction on March 28/29! The sale is with Philip Weiss Auctions .

The weekend of Mar. 28-29 will comprise three sessions – two on Saturday and one on Sunday. The first Saturday session, beginning at 10 a.m., will feature an impressive collection of medical and scientific instruments. Included will be medical and dental items; a collection of calculators and slide rules; office items (early check punches and registers); and pre-1950 spy and surveillance equipment.

Highlights will include a previously unrecorded 19th-century Kwik Calculator; Pascaline Calculator; McFarlane's Calculating Cylinder; Higgins Patent (mechanical) Calculating Triangle; Wheilon Calculometer; Bair-Fulton American Calculator; and numerous 19th- and 20th-century slide rules, including some special-purpose rules for artillery, brewing and other, more esoteric applications. Check it out.

Monday, 9 March 2009

Very strange instrument in Peter Delehar's Shop

Peter Delehar started the Scientific Instrument Fair in London 24 years ago and has enthusiastically dealt in esoteric and interesting instruments in the same shop his father started 90 years ago this year.Peter has a reputation for exhaustive research on most of his pieces and this one is no exception:here's what he has to say about it:This rare, unusual instrument, is made of glazed paper on card and is contained in its original marbled card slip case. It is entirely covered, on both sides, including the edges, with tables, gauge points and an arc for use as a clinometer. It was invented in 1852 by Maximilion Robert Pressler (1815-1886), the father of the modern science of forestry.
It is signed *PRESSLER’S INGENIEUR-MESSKNECHT Tharand. Dresden*. The scales include those titled ‘*Reciproken*’, ‘*Bogen*’, ‘*Kreis*’, ‘*Qw*’, ‘C*w*’, ‘*Centi*’, ‘*Tg*’, etc. and many conversion factors.

To use this as a clinometer the flaps are folded over each other (they are not the same length to allow for the thickness of the card) and it is placed on a post or held in the hand. The plummet (bob missing) indicated the angled observed with the missing, loose sight.

A remarkable, perhaps even unique survival. Width, when laid flat, 8.6 inches (21.8cms). the condition of the slip case is good but noting that there is some wear on one corner. The condition of the instrument is is also good, but also noting that the hinges are slightly frail, the plummet and sight are missing
and there is slight discolouration of the paper.

See: R. Max. Pressler, /MathematischeBrieftasche mit Ingenieur-Messknecht, Dresden 1860/.
M.R. Pressler, /Der Messknecht als Mastknecht, Braunsweig 1853/.
/Zur Verwandlung der Messknechtstafel in das Visirinstrument. N.D. (1860?)/

Sunday, 8 March 2009

Otacoustical Instruments

I've just come across a catalogue I'd mislaid in a mountain of paperwork. Its a 1912 catalogue of Otocoustical Instruments to aid the Deaf. Many of the instruments are disguised aids discretely covered in hair or camouflaged as a vase of flowers on the table. This one proudly tells the world "I am hard of hearing" and looks like a very large early twentieth century iPod! The amplification of these devices isn't often very many dBs but obviously seeing somebody carrying such a device is going to make people speak to them much more loudly than they would otherwise. This one is known as the "Staniland" and cost a staggering 15 guineas, ie £15.75, in 1912. To see a very good collection of eartrumpets, look at fair exhibitor, Laurie Slater's website at
There's a very good book on antique hearing devices written by Elisabeth Bennion and available from
www. .

Big Changes at Portobello Road

Many collectors like to pop into Portobello Road on the Saturday before the Scientific Instrument Fair, but when they come in April they will find the whole of Lipkas Arcade in Westbourne Grove shut down for renovation. Four dealers in scientifc and pharmaceutical antiques have been forced to move out. Fletcher Wallis has moved to the basement of the Admiral Vernon Arcade, Andrew Crawforth has moved further along Westbourne Grove to 292, Lawrence Cooper, The Antique Dispensary Ltd, has moved up the Portobello to the Chelsea Arcade, just down from Vic Burness, who is still in Roger's. I'm not sure yet where Michael Forrar, Principia Fine Art is moving to, but more of this in future posting.

Saturday, 7 March 2009

How did a farmer weigh his cow sheep or pig in the field?

In the nineteenth century, how did a farmer weigh his livestock in the field? He might have used a clever little slide rule known as "The Cattle Gauge & Key to the Weighing Machine" arranged by J Ewart, Newcastle on Tyne. These rules were often manufactured by James Tree of 22, Charlotte Street, Blackfriars Road, London. The method used involved measuring the length and girth of the animal and using a ready reckoner on the rule, giving percentage values of meat on the carcass, to calculate the weight using a series of gauge points. The rules are made mainly from box but sometimes with ivory slides and occasionally completely from ivory. The Tree family made rules at Charlotte Street from 1832-1895, according to the Directory of British Scientific Instrument Makers 1550-1851, but these rules probably date from the second quarter of the nineteenth century. Although this rule is uncommon, its just the sort of thing that turns up at the fair. Several dealers specialise in slide rules and calculators, notably David & Yola Coffeen, from Tesseract , Peter Delehar , and Desmond Squire .

Friday, 6 March 2009

The 46th International Scientific Instrument Fair

The 46th International Antique Scientific Instrument, Early Technology and Medical Instrument Fair is held on Sunday 26 April 2009 at the Thistle Hotel Marble Arch in London. There are over fifty dealers from around the world offering the biggest and most diverse collection of instruments and books including: marine chronometers, navigational instruments, sundials, globes, weights and measures, physics demonstration and research apparatus, microscopes, slides and accessories, telescopes, telegraphs, medical and pharmaceutical antiques, surgical instruments, drawing instruments and early mechanical calculators and much more.

The fair is held from 10am-3pm at the Thistle Hotel Marble Arch, London W1H 7EH. Entrance price £7.50

for enquiries contact Matthew Nunn +44 (0) 7968 753 218 or go to

The 47th Fair will be held at the Holiday Inn, Bloomsbury, Coram Street, London WC1N 1HT on 18 October
If you are interested in exhibiting at this fair please contact Desmond Squire, at dgsem(at)