21, Rue de L’Odéon | au fond de la Cour1
Paris le 22 Août
Monsieur
J’ai l’honneur de repondre a votre lettre du 16 courant et je vous donne ci contre le prix des appareils necessaires pour un cours complet d’optique. Cependant, je n’ai pas mis dans cette liste les appareils que j’ai déjà eu l’honneur de vous fournir et qui sont indispensables.
Dans l’attente de vos orders, je vous prie Monsieur de recevoir mes salutations les plus empressées et de me croire votre très dévoué serviteur | J. Duboscq
Liste des appareils pour répeter toutes les expériences d’optique.
√ 2 lentilles de 33 centimetres de foyer concave et convexe – 60″
1 diaphragme à ouverture rectiligne – 20″
1 id à fleche pour la refraction – 10″
√ 3 miroirs plan, concave et convexe
√ 1 prisme à angle droit reflexion totale – 45″
1 prisme de flint très pur pour les raies – 60″
1 prisme [a] flacon pour avoir un spectre avec divers liquides de dispersion differente – 45ʹ
1 prisme achromatique a 3 verres – 50″
1 prisme a angle variable pour l’achromatisme de la reflexion totale – 200ʹ
1 lentille et ses diaphragmes pour les aberrations de spéricité et de réfrangibilité – 90ʹ
verre violet et dessin pour l’experience de M. Stokes – 20ʹ
1 Cuve a diagonale pour la refraction – 36ʹ
Cuve pour la decomposition de l’eau et pour la recomposition métallique – 20ʹ
× 1 appareil a deux corps pour la projection des photographies, objet d’Histoire naturelle
globules du sang. &c &c – 250ʹ
appareil pour les anneaux coloré de Newton – 40ʹ
appareil pour les anneaux a liquides - 72ʹ
id id les lames epaisses – 50ʹ
appareil pour projeter la double refraction, couleurs complementaires de Arago, les
cristaux a axes, les lames de chaux, les verres trempés comprimées &c – 250ʹ
presse pour comprimer – 20ʹ
presse pour courber – 20ʹ
pince a chauffer – 18ʹ
× Disque de newton transparent – 30ʹ
√ Lentille cylindrique avec prisme pour recomposer la lumiere – 60ʹ
Appareil pour les hyperboles mobiles – 40ʹ
2 parallelepipedes fresnel – 40ʹ
Collection de cristaux [a axes] verre trempés chaux sulfatée &c [aussi] 20ʹ
Photographes objets microscopiques et autre, la pièce 5
21, Rue de L’Odéon | at the bottom of the court1
Paris, August 22nd
Sir,
It is my pleasure to respond to your letter of the 16th of this month,2 and I am providing you herewith the price of the apparatus necessary for a complete optics course. However, I have not included in this list the apparatus that I have had the honour of supplying you, and which are indispensable.
While waiting for your orders, I am asking you, Sir, to accept my most considerate greetings. Sincerely, your much devoted servant | J. Duboscq
List of the apparatus used in performing all the optical experiments.
√ 2 lenses concave and convex each of focal length 33 centimetres – 60″3
1 diaphragm with a rectilinear aperture – 20″
1 ditto with an arrow [indicating] refraction – 10″
√ 3 plane mirrors, concave and convex
√ 1 right-angle prism for total reflection – 45″
1 very pure flint prism for the [dispersion of] rays – 60″
1 prism with flask to obtain a spectrum with various liquids of different dispersion – 45ʹ
1 achromatic prism with 3 glasses4 – 50″
1 prism with a variable angle for the achromatism and the total reflection – 200ʹ
1 lens and its diaphragms for [measuring] spherical aberration and aberration by refraction – 90ʹ
Violet glass and a drawing for Mr. Stokes’ experiment5 – 20ʹ
1 diagonal vessel for refraction – 36ʹ
Vessel for the decomposition of water6 and its metallic recomposition – 20ʹ
1 device with two [parts?] for the projection of photographs, natural history objects, blood cells, &c &c – 250ʹ
Apparatus for Newton’s coloured rings7 – 40ʹ
Apparatus for producing rings in liquid – 72ʹ
ditto for thick plates8 – 50ʹ
× Apparatus for projecting double refraction, Arago’s complementary colours, crystals with axes, livers of lime, compressed tempered glass etc. – 250ʹ
a press for compression9 – 20ʹ
a press for bending – 20ʹ
pliers for heating – 18ʹ
× transparent Newton’s disc10 – 30ʹ
√ Cylindrical lens with prism for the recombination of light – 60ʹ
Device for [displaying] movable hyperbolic fringes11 – 40ʹ
2 Fresnel rhombs – 40ʹ
A collection of crystals [with axes], tempered glass, sulfate of lime &c [as well] 20ʹ
Microscopic object photographs and others, [priced] per item – 5ʹ
RI MS JT/1/D/180
21, Rue de L’Odéon | au fond de la Cour: The address forms part of a printed heading which also includes the wording ‘Exposition de Londres | Council Medal | J. Duboscq’ (Duboscq had been awarded a Council Medal for the optical instruments he displayed at the Great Exhibition in London in 1851) ‘Élève & Succr de Soleil’ (Duboscq was the student and successor of the eminent optician and mathematical instrument maker Jean Baptiste François Soleil, who was also his father-in-law) ‘Les lettres adressées à la maison J. Duboscq, doivent être affranchise’ (Letters written to the house of J. Duboscq must be postmarked).
your letter of the 16th of this month: letter missing.
60″: The numbers at end of each line indicates the price, in francs. In the RI Managers’ Minutes (vol. XI, f. 117) for 5 November 1855, it was ‘Resolved, That a sum not exceeding £40 [about 1,000 francs] be placed at Dr. Tyndall’s disposal, to purchase apparatus from M. Duboscq at Paris.’
achromatic prism with 3 glasses: Probably a compound achromatic prism composed of 3 pieces of glass.
Mr. Stokes’ experiment: In his paper ‘On the Change of Refrangibility of Light’ (Phil. Trans., 142 (1852), pp. 463–562), Stokes had shown that, while rays of some colours passed through a flask containing a solution of sulphate of quinine unhindered, others had been changed in colour, while the fluid became fluorescent.
Vessel for the decomposition of water: a voltameter.
Newton’s coloured rings: Book 2 of Newton’s Opticks (1704 and later editions) contains numerous experiments with these rings.
thick plates: Newton discussed these in book 2, part 4, of his Opticks.
a press for compression: for compressing, say, samples of glass in order to alter their optical characteristics.
Newton’s disc: A wheel divided into seven sectors, each painted one of the seven colours of the spectrum. When rotated the disc appears white; showing that white is a mixture of these colours.
Device … hyperbolic fringes: For displaying the polarisation of light by crystals.
Please cite as “Tyndall1131,” in Ɛpsilon: The John Tyndall Collection accessed on