1432 B.C. Iron said to have been first discovered.

424 B.C. Lenses made and used by the Greeks. And a lens has been found in the ruins of Nineveh.

79 A.D. Glass known and used by the Romans.

697. Glass brought to England.

1100. Alcohol first obtained by the alchemist, Abucasis.

1287. Nitric acid first obtained by Raymond Lully. Present properties made known by Dr. Priestley, 1785.

1297. Camera-obscura constructed by Roger Bacon.

1400. Chloride of gold solution known to Basil Valentine.

1500. Camera-obscura improved by Baptista Porta.

1555. Chloride of silver blackening by the action of light. Doubtless it was the knowledge of this that induced Thomas Wedgwood and Sir Humphry Davy to make their experiments.

1590. Paper first made in England, at Dartford, Kent, by Sir John Speilman. It is said that the Chinese made paper 170 years B.C.

1646. Magic lantern invented by Athanasius Kircher. 1666. Sir Isaac Newton divided a sunbeam into its seven component parts, and re-constructed the camera-obscura.

1670. Salt mines of Staffordshire discovered.

1727. J. H. Schulze, a German physician, observed that light blackened chalk impregnated with nitrate of silver solution and gold chloride.

1737. Solution of nitrate of silver applied to paper, by Hellot.

1739. Chloride of mercury made by K. Neumann.

1741. Platinum first known in Europe: M. H. St. Claire Deville’s new method of obtaining it from the ore, 1859.

1750. J. Dolland, London, first made double achromatic compound lenses.

1757. Chloride of silver made by J. B. Beccarius.

1774. Dr. Priestly discovered ammonia to be composed of nitrogen and hydrogen; but ammonia is as old as the first decomposition of organic matter.

1777. Charles William Scheele observed that the violet end of the spectrum blackened chloride of silver more rapidly than the red end. Chlorine discovered.

1779. Oxalate of silver made by Bergmann.

1789. Uranium obtained from pitch-blende by Klaproth.

1791. Thomas Wedgwood commenced experiments with a solution of nitrate of silver spread upon paper and white leather, and obtained impressions of semi-transparent objects and cast shadows. Sir Humphry Davy joined him later.

1797. Nitrate of silver on silk by Fulhame.

1799. Hyposulphite of soda discovered by M. Chaussier.

1800. John William Ritter, of Samitz, in Silesia, observed that chloride of silver blackened beyond the violet end of the spectrum, thus discovering the action of the ultra violet ray.

1801. Potassium discovered by Sir Humphry Davy.

1802. Examples of Heliotypes, by Wedgwood and Davy, exhibited at the Royal Institution, and process published. 1803. Palladium discovered in platinum by Dr. Wollaston.

1808. Strontium obtained from carbonate of strontia by Sir Humphry Davy.

1812. Iodine discovered by M. D. Curtois, of Paris.

— Nitrate of silver and albumen employed by D. Fischer.

1813. Ditto investigated by M. Clement.

1814. Joseph NicÉphore de NiÉpce commenced experiments with the hope of securing the pictures as seen in the camera-obscura.

— Iodide of silver made by Sir H. Davy.

1819. Sir John Herschel published the fact that hyposulphite of soda dissolved chloride and other salts of silver.

1824. NiÉpce obtained pictures in the camera-obscura upon metal plates coated with asphaltum, or bitumen of Judea.

— L. G. M. Daguerre commenced his researches.

— Permanganate of potash. Fromenkerz.

1826. Bromine discovered in sea-water by M. Balard.

— Bromine of silver made.

1827. NiÉpce exhibited his pictures in England, and left one or more, now in the British Museum.

1829. NiÉpce and Daguerre entered into an alliance to pursue their researches mutually.

1832. Evidence of Daguerre employing iodine.

1837. Rev. J. B. Reade, of Clapham, London, obtained a photograph in the solar microscope, and employed tannin as an accelerator and hyposulphite of soda as a fixer for the first time in photography.

1838. Reflecting stereoscope exhibited by Charles Wheatstone.

— Mungo Ponton observed that light altered and hardened bichromate of potash, and produced yellow photographs with that material. This discovery led to the invention of the Autotype, Woodburytype, Collotype, and other methods of photo-mechanical printing. 1839. Daguerre’s success communicated to the Academy of Science, Paris, by M. Arago, January 7th.

— Electrotype process announced.

— Professor Faraday described Fox Talbot’s new method of photogenic drawing to the members of the Royal Institution, January 25th.

— Fox Talbot read a paper, giving a full description of his process, before the Royal Society, January 31st.

— Sir John Herschel introduced hyposulphite of soda as a fixing agent, February 14th.

— Dr. Alfred Swaine Taylor employed ammonia nitrate of silver in preference to chloride of silver for making photogenic drawings, and employed hyposulphite of lime in preference to hyposulphite of soda for fixing.

— Daguerre’s process published in August, and patent, for England, granted to Mr. Beard, London, August 14th.

— “History and Practice of Photogenic Drawing”; L. S. M. Daguerre. Published September.

— First photographic portrait taken on a Daguerreotype plate by Professor. J. W. Draper, New York, U. S., in the autumn of this year.

1840. “On the Art of Photogenic Drawing,” by Alfred S. Taylor, lecturer on chemistry, &c., at Guy’s Hospital. Published by Jeffrey, George Yard, Lombard Street, London.

— “The Handbook of Heliography, or the Art of Writing or Drawing by the Effect of Sunlight, with the Art of Dioramic Painting, as practised by M. Daguerre.” Anon.

— Wolcott’s reflecting camera brought from America to England and secured by Mr. Beard, patentee of the Daguerreotype process.

— The moon photographed for the first time by Dr. J. W. Draper, of New York, on a Daguerreotype plate.

— John Frederick Goddard, of London, inventor of the polariscope and lecturer on chemistry, employed chlorine added to iodine, and afterwards bromine, as accelerators in the Daguerreotype process.

1840. Antoine F. J. Claudet, F.R.S., of London, employed chlorine for the same purpose.

— M. Fizeau, of Paris, deposited a film of gold over the Daguerreotype picture after the removal of the iodine, which imparted increased brilliancy and permanency.

— Chloride of platinum employed by Herschel.

— Fox Talbot’s developer published September 20th.

1841. Calotype process patented by Fox Talbot, September 20th.

— First photographic compound portrait lens made by Andrew Ross, London.

— Towson, of Liverpool, noted that chemical and visual foci did not coincide. Defect corrected by J. Petzval, of Vienna, for Voightlander.

— “A Popular Treatise on the Art of Photography, including Daguerreotype and all the New Methods of Producing Pictures by the Chemical Agency of Light,” by Robert Hunt, published by R. Griffin, Glasgow.

— Daguerre announced an instantaneous process, but it was not successful.

1842. Sir John Herschel exhibited blue, red, and purple photographs at the Royal Institution.

— “Photography Familiarly Explained,” by W. R. Baxter, London.

1843. “Photogenic Manipulation,” by G. T. Fisher Knight, Foster Lane.

— Treatise on Photography by N. P. Lerebours, translated by J. Egerton.

1844. Fox Talbot issued “The Pencil of Nature,” a book of silver prints from calotype negatives.

— C. Cundell, of London, employed and published the use of bromide of potassium in the calotype process. 1844. “Researches on Light and its Chemical Relations,” by Robert Hunt. First edition; second ditto, 1854.

— Robert Hunt recommended proto-sulphate of iron as a developer for Talbot’s calotype negatives; also oxalate of iron and acetate of lead for other purposes.

— A. F. J. Claudet patented a red light for “dark room,” but at that date a red light was not necessary, so the old photographers continued the use of yellow lights.

1845. “Photogenic Manipulations:” Part 1, Calotype, &c.; Part 2, Daguerreotype. By George Thomas Fisher, jun. Published by George Knight and Sons, London.

— “Manual of Photography,” including Daguerreotype, Calotype, &c., by Jabez Hogg. First edition. Second ditto, including Archer’s collodion process, bichloride of mercury bleaching and intensifying, and gutta-percha transfer process, 1856.

1845. “Practical Hints on the Daguerreotype; Willats’s Scientific Manuals.”

— “Plain Directions for Obtaining Photographic Pictures by the Calotype and other processes, on paper; Willats’s Scientific Manuals.” Published by Willats, 98, Cheapside; and Sherwood, Gilbert, and Piper, Paternoster Row.

1846. Gun-cotton made known by Professor SchÖnbein, of Basel.

1847. Collodion made by dissolving gun-cotton in ether and alcohol, by Mr. Maynard, of Boston, U.S.

1848. “Photogenic Manipulation:” Part II., Daguerreotype, by Robert Bingham. Published by George Knight and Sons, London.

— Albumen on glass plates first employed for making negatives by M. NiÉpce de Saint Victor. Process published June 13th.

— Frederick Scott Archer experimented with paper pulp, tanno-gelatine, and iodised collodion, and made collodion negatives in the autumn. 1849. Collodion positive of Hever Castle, Kent, made by Frederick Scott Archer early in the year.

— M. Gustave Le Gray suggested the application of collodion to photography.

1850. “A Practical Treatise on Photography upon Paper and Glass,” by Gustave Le Gray. Translated from the French by Thomas Cousins, and published by T. and R. Willats. This book is said to contain the first printed notice of collodion being used in photography.

— R. J. Bingham, London, suggested the use of collodion and gelatine in photography.

— M. Poitevin’s gelatine process, published January 25th.

1851. Frederick Scott Archer published his collodion process in the March number of The Chemist, and introduced pyrogallic acid as a developer December 20th.

— Fox Talbot announced his instantaneous process, and obtained, at the Royal Institution, a copy of the Times newspaper, while revolving rapidly, by the light of an electric spark.

— NiÉpce de St. Victor’s heliochromic process, published June 22nd. Examples sent to the judges of the International Exhibition of 1862. See Jurors’ Report thereon, pp. 88-9.

— Sir David Brewster’s improved stereoscope applied to photography.

1851. “Photography, a Treatise on the Chemical Changes produced by Solar Radiation, and the Production of Pictures from Nature, by the Daguerreotype, Calotype, and other Photographic Processes,” by Robert Hunt. Published by J. J. Griffin and Co., London and Glasgow.

1852. “Archer’s Hand-Book of Collodion Process.” Published May 14th. Second edition, enlarged; published 1854.

— “Archer’s Collodion Positive Process.” Published July 20th.

— Fox Talbot’s photo-engraving on steel process; patented October 29th. 1853. A Manual of Photography, by Robert Hunt, published.

— Photographic Society of London founded. Sir Charles Eastlake, P.R.A., President; Roger Fenton, Esq., Secretary. First number of the Society’s Journal published March 3rd.

— Cutting’s American patent for use of bromides in collodion obtained June 11th, and his Ambrotype process introduced in America.

— “The Waxed-Paper Process,” by Gustave Le Gray. Translated from the French with a supplement, by James How. Published by G. Knight and Co., Foster Lane, Cheapside.

— Frederick Scott Archer introduced a triple lens to shorten the focus of a double combination lens.

1854. E. R., of Tavistock, published directions for the use of isinglass as a substitute for collodion.

— First series of photographic views of Kenilworth Castle, &c., from collodion negatives, published by Frederick Scott Archer.

— Liverpool Photographic Journal, first published by Henry Greenwood, bi-monthly.

— First roller-slide patented by Messrs. Spencer and Melhuish, May 22nd.

— Fox Talbot first applied albumen to paper to obtain a finer surface for photographic printing.

— Photo-Enamel process; first patent December 13th.

— Dry collodion plates first introduced.

1855. M. Poitevin’s helioplastic process patented February 20th.

— Dr. J. M. Taupenot’s dry plate process introduced.

— Photo-galvanic process patented June 5th.

— “Hardwich’s Photographic Chemistry.” First edition, published March 12th.

— Ferrotype process introduced in America by Mr. J. W. Griswold.

1856. “Photographic Notes.” Edited by Thomas Sutton. Commenced January 1st; bi-monthly. 1856. Sutton’s Calotype process, published March.

1856. Dr. Hill Norris’s dry plate process. Patented September 1st.

1856. Caranza published method of toning silver prints with chloride of platinum.

1857. Moule’s photogene, artificial light for portraiture. Patented February 18th.

— Carte-de-visite portraits introduced by M. Ferrier, of Nice.

— Kinnear Camera introduced. Made by Bell, Edinburgh.

1858. Pouncy’s Carbon process patented April 10th.

— Skaife’s Pistolgraph camera introduced.

1858. J. C. Burnett exposed the back of the carbon paper and obtained half-tones.

— Fox Talbot’s photo-etching process, patented April 20th.

— Paul Pretsch’s photo-engraving process introduced.

— “Sutton’s Dictionary of Photography,” published August 17th.

— The Photographic News, founded, weekly. First number published September 10th, by Cassell, Petter, and Galpin, London.

— “Fothergill Dry Process,” by Alfred Keene, published August.

1859. Sutton’s panoramic camera patented, September 28th.

— Photo-lithographic Transfer process patented by Osborne, in Melbourne, Australia.

— Wm. Blair, of Perth, secured half-tone in carbon printing by allowing the light to pass through the back of the paper on which the pigment was spread.

— Asser, of Amsterdam, also invented a photo-lithographic transfer process about this time.

1860. “Principles and Practice of Photography,” by Jabez Hughes. First edition published; fourteenth edition, 1887.

— Fargier coated carbon surface with collodion, exposed, and transferred to glass to develop.

— Spectroscope invented by Kertchoff and Bunsen. 1860. “Year-Book of Photography,” edited by G. Wharton Simpson, first published.

— Improved Kinnear camera with swing front and back by Meagher.

1861. Captain Dixon’s iodide emulsion process patented, April 29th.

— M. Gaudin, of Paris, employed gelatine in his photogene, and published in La LumiÈre his collodio-iodide and collodio-chloride processes.

— H. Anthony, New York, discovered that Tannin dry plates could be developed by moisture and ammonia vapour.

1862. “Alkaline Development,” published by Major Russell.

— Meagher’s square bellows camera, with folding bottom board, exhibited at the International Exhibition. Noticed in Jurors’ Report.

— Parkesine, the forerunner of celluloid films, invented by Alexander Parkes, of Birmingham.

1863. Pouncy’s fatty ink process; patented January 29th.

— Toovey’s photo-lithographic process; patented June 29th.

— “Tannin Process,” published by Major Russell.

— “Popular Treatise on Photography,” by D. Van Monckhoven. Translated from the French by W. H. Thornthwaite, London.

1864. Swan’s improved carbon process; patented August 27th.

— “Collodio-Bromide Emulsion,” by Messrs. B. J. Sayce and W. B. Bolton; published September 9th.

— “Collodio-Chloride Emulsion,” by George Wharton Simpson; published in The Photographic News, October 28th.

— Willis’s aniline process; patented November 11th.

— Obernetter’s chromo-photo process; published.

— Instantaneous dry collodion processes by Thomas Sutton, B.A. Sampson, Low, Son, and Marston, London.

1865. Paper read on “Collodio-Chloride Emulsion,” by George Wharton Simpson, at the Photographic Society, March 14th. 1865. Photography, a lecture, by the Hon. J. W. Strutt, now Lord Rayleigh, delivered April 18th; and afterwards published.

— Eburneum process; published by J. Burgess, Norwich, in The Photographic News, May 5th.

— Bromide as a restrainer in the developer; published by Major Russell.

1865. Interior of Pyramids of Egypt, photographed by Professor Piazzi Smyth with the magnesium light.

— W. H. Smith patented a gelatino-bromide or gelatino-chloride of silver process for wood blocks, &c.

1866. Magic photographs revived and popularised.

— Woodburytype process patented by Walter Bentley Woodbury, of Manchester, July 24th.

— Photography reviewed, in British Quarterly Review, by George Wharton Simpson, October 1st.

1867. M. Poitevin obtained the balance of the Duc de Luynes’s prize for permanent printing.

— Cabinet portraits introduced by F. R. Window, photographer, Baker Street, London.

1868. W. H. Harrison experimented with gelatino-bromide of silver and obtained results, though somewhat rough and unsatisfactory.

1869. John Robert Johnson’s carbon process double transfer patented.

— “Pictorial Effect in Photography,” by H. P. Robinson, first edition. London: Piper and Carter.

1870. Thomas Sutton described Gaudin’s gelatino-iodide process.

— Jabez Hughes toned collodion transfers with chloride of palladium.

— John Robert Johnson’s single transfer process for carbon printing patented.

1871. Dr. R. L. Maddox, of Southampton, published his experiments with gelatino-bromide of silver in the British Journal of Photography, September 8th. 1872. “Emaux Photographiques” (photographic enamels), second edition, by Geymet and Alker, Paris.

1873. J. Burgess, of Peckham, advertised his gelatino-bromide of silver emulsion, but it would not keep, so had to be withdrawn.

— Ostendo non Ostento published a gelatino-bromide of silver formula with alcohol.

— Platinotype process patented by W. Willis, junior, June 1st.

1873. R. Kennett’s gelatino-bromide of silver pellicle patented November 20th.

— “The Ferrotypers’ Guide” published by Scovill Manufacturing Company, New York.

1874. R. Kennett issued his gelatino-bromide of silver dry plates in March.

— Gelatino-bromide of silver paper first announced by Peter Mawdsley, of Liverpool Dry Plate Company.

— “Backgrounds by Powder Process” published by J. Werge, London.

— Flexible supports in carbon printing patented by John Robert Sawyer, of the Autotype Company.

— Leon Lambert’s carbon printing process patented.

1875. Demonstrations in carbon printing by L. Lambert given in London and elsewhere.

— Eder and Toth intensified collodion negatives and toned lantern slides with chloride of platinum.

1876. “Practical Treatise on Enamelling and Retouching,” by P. PiquepÉ, Piper and Carter, London.

1877. Ferrous oxalate developer published June 29th.

— Wratten precipitated the gelatine emulsion with alcohol, and so avoided the necessity of dialysing.

1878. Improvement in platinotype patented by W. Willis, junior, July.

— Abney’s “Treatise on Photography” published.

— Abney’s “Emulsion Process” published. 1879. J. Werge’s non-actinic developing tray introduced at the South London Photographic Society.

1880. “Principles and Practice of Photography,” by Jabez Hughes, comprising instructions to make and manipulate gelatino dry plates, by J. Werge. London: Simpkin and Marshall, and J. Werge.

— Gelatino-bromide of silver paper introduced by Messrs. Morgan and Kidd.

— Platinotype improvement patent granted.

— Iodides added to gelatino-bromide of silver emulsions by Captain W. de W. Abney.

1880. Warnerke’s sensitometer introduced.

— “The Argentic Gelatino-Bromide Workers’ Guide,” by John Burgess. W. T. Morgan and Co., Greenwich.

— “Photography; its Origin, Progress, and Practice,” by J. Werge. London: Simpkin, Marshall, and Co.

— Hydroquinone developer introduced by Dr. Eder and Captain Toth.

1881. Stannotype process introduced by Walter Woodbury.

— Photographers in Great Britain and Ireland 7,614 as per census returns.

— “Modern Dry Plates; or Emulsion Photography,” by Dr. J. M. Eder, translated from the German by H. Wilmer, edited by H. B. Pritchard. London: Piper and Carter.

— “Pictorial Effect in Photography,” by H. P. Robinson (cheap edition). Piper and Carter.

— “The Art and Practice of Silver Printing,” by H. P. Robinson and Captain Abney. Piper and Carter.

1882. Herbert B. Berkeley recommended the use of sulphite of soda with pyrogallic acid to prevent discolouration of film.

— “Recent Advances in Photography” (Cantor Lectures, Society of Arts), Captain Abney. London: Piper and Carter.

1882. “The A B C of Modern Photography,” comprising practical instructions for working gelatine dry plates, by W. K. Burton. London: Piper and Carter. 1882. “Elementary Treatise on Photographic Chemistry,” by A. Spiller. London: Piper and Carter.

1883. Translation of Captain Pizzighelli and Baron A. Hubl’s booklet on “Platinotype;” published in The Photographic Journal.

— Orthochromatic dry plates; English patent granted to Tailfer and Clayton, January 8th.

— “The Chemical Effect of the Spectrum,” by Dr. J. M. Eder. (Translated from the German by Captain Abney). London: Harrison and Sons.

1883. “The Chemistry of Light and Photography,” by Dr. H. Vogel. London: Kegan Paul.

1884. “Recent Improvements in Photo-Mechanical Printing Methods,” by Thomas Bolas, Society of Arts, London.

— “Picture-Making by Photography,” by H. P. Robinson. London: Piper and Carter.

1885. “Photography and the Spectroscope,” by Capt. Abney, Society of Arts.

— “The Spectroscope and its Relation to Photography,” by C. Ray Woods. London: Piper and Carter.

— “Photo-Micrography,” by A. C. Malley; second edition. London: H. K. Lewis.

1886. Orthochromatic results exhibited by Dixon and Sons at the photographic exhibition in October.

— English patent rights of Tailfer and Clayton’s orthochromatic process secured by B. J. Edwards and Co., Nov. 18th.

1887. Platinotype improvements; two patents.

1888. Pizzighelli’s visible platinotype printing paper put on the market in June.

1889. Eikonogen developer patented by Dr. Andresen, of Berlin, Germany, March 26th.

— Wire frames and supports in camera extensions patented by Thomas Rudolph Dallmeyer and Francis Beauchamp, November 6th.