Introduction

Lantern slides represent the main physical component of works in the art of projection. They are technical artefacts constructed and designed to create mutable luminous images on the screen. They were produced to be used in live performance events combining performance elements such as recitations, singing and music with images on a screen. The article The Dispositif of the Historical Art of Projection introduces the function of lantern slides as ‘technical images’ and describes the characteristic difference between prefabricated technical image information and performative screen image manifestation. As such, the structural and compositional principle of the screen interacts with the theatrical volatility of the projected images. Image sequences of arbitrary length permit the visual configuration of fictional narratives and historical occurrences, the differentiated portrayal of natural science topics, and the presentation of fantastical worlds and breath-taking colour effects.

Prior to a magic lantern show operators and performers choose the appropriate slides for the performance. All visual representations and visual effects utilised as technical image information must be available on glass slides (or possibly similar transparent materials or film) beforehand. During the performance the operator inserts the slides into the slide stage of a projection apparatus (‘lantern’), and so produces images on a screen or similar surface, in a planned chronological order. To the well-trained eye of an experienced operator, the potential screen image manifestation is quickly apparent on direct inspection of individual slides.

Experimental approaches to the projection of historical slides reveal considerable differences between the lantern slides themselves and the images visible on the projection surface. Most slides have an image diameter of roughly three inches (7.5cm), though some elaborately designed unique specimens display image diameters of up to eight inches (20cm). As projected images they can be enlarged to sizes ranging from six to twenty-five feet (2-8m) in diameter. Thus, delicate details and image errors may be only visible in the screen projection, and not necessarily upon inspection of the artefact. In contrast, the mechanical components of movable slides – such as cranks, rack-wheels and sliding glass plates – are always visible when the artefacts are examined, but the motion effects for which these mechanisms were designed are only realised detached from the artefacts, in their representation as screen images. For example the technical image information of dissolving views consists of several (at least two) individual slides, but the ‘dissolving view’ effect is achieved through changes and superimpositions only visible on the screen. Accordingly, operators recognised the indispensable need to check the screen image manifestations before coordinating them with the performances of live performers and musicians.

Examples of surviving lantern slides

The first illustration of a surviving lantern slide shows a square slide on a light box. Its edge lengths are 3¼ inches (8.3cm). It consists of two glass plates bound together by a circumferential paper binding strip: one plate carries the image, the other serves as a protective cover glass. Between both glass plates, a format mask, made of black paper, frames a square image detail of 7 x 7 cm with rounded corners. On the format mask, labels read “Ora pro nobis”, image number 3, a copyright notation and the declaration “from life models”.

The slide image, in transmitted light, shows a group of people in front of the portal of a church. On closer inspection, the photographic nature of the image becomes apparent. The hand-coloured image shows a scene taken in a studio, with the pictured characters standing in front of a painted background which represents a church with an open door. The virtual agents embody a social contrast: well-dressed churchgoers stand opposite a barefoot girl clad in rags in the snow. The photographed scene is reminiscent of literary depictions of poverty such as Hans Christian Andersen’s story The Little Match Girl. The image is part of the late Victorian lantern slide set Ora Pro Nobis (Bamforth, UK, 1897), which consists of eight slides illustrating a commercially published song recounting the death of a poor orphan girl. eLaterna Archive contains archive editions of four surviving versions of this slide set, which have been compiled and commented on in a critical edition.

Ora Pro Nobis is exemplary of thousands of lantern slide sets, produced in standardised slide formats starting from the 1870s. The introduction of standardised dimensions for lantern slides served to facilitate distribution as well as the technical standardisation of performances. Slides in a standard format make up the bulk of the surviving slides, as well as the greatest proportion of all slides recorded in LUCERNA. The standard of a 3¼ inch (8.3cm) square was common in the UK and Germany; in France and the USA the standard was rectangular, 8.3 x 10cm or 3¼ x 4 inches.¹

The next example shows a pair of images of Lake Thun in Switzerland. One slide shows the scenery by day and the other the same by night. The transparent images are on circular glass plates embedded in rectangular wooden frames, with a label on the frame giving the title, image number and manufacturer. Another label on the slide showing the day scene shows the handwritten annotation of an operator advising the slide to be inserted in a “right hand lantern”. These projections with multiple projection apparatuses were called dissolving views (‘Nebelbilder‘ in German) because the screen images ‘dissolved’ into each other on screen to create a transformation effect.²

In an early lecture on the history of the art of projection, the German manufacturer of optical lanterns and lantern slides Franz Paul Liesegang portrays enchanting transformations of a landscape from day to night or from summer to winter, for which a projection apparatus with two lenses was required. The same technique made it possible to superimpose parts of images (such as movable figures) or effects (such as the appearance of the Northern Lights) on the screen image and let them disappear again. The slide set The Emigrant Ship (‘Das Auswandererschiff’), was designed for an apparatus with three lenses: a sailing vessel is caught in a thunderstorm and hit by lightning. A movable image of flames and smoke (‘Brandplatte’ in German) is then superimposed to show the ship ablaze.³

The slide set The Emigrant Ship was offered internationally in various versions. The example of the first slide from a British version shows the technical construction of a complex movable image.⁴ A mechanism moves four glass plates relative to each other to show the departure of the vessel through moving waves. The archive edition for this set in eLaterna Archive shows the mechanism in detail.

The eLaterna Archive records the surviving slide sets in digital archive editions as main constituents of works in the historical art of projection. These consist of all surviving components of the works and are represented as digital objects ready to be studied. Examination tools document the glass slides in all views as three-dimensional material artefacts and also show how they appear on the screen as mutable projected images. The metadata schemata of eLaterna and LUCERNA categorise slides and slide sets based on technical and artistic criteria.

Slide formats and technical description

Factors such as performance programming, projection technique, production and distribution determined the format and design of lantern slides. The construction of a slide primarily needed to comply with its function as technical image information. The technical designs of the transparent images and effects, as well as the various image moving mechanisms, determine the visual occurrences on the screen. The frames of lantern slides were manufactured to fit the slide stages of projection apparatuses or their ‘slide carriers’, accessories which position the transparent images in the optical system of the apparatus.

Moving mechanisms were usually integrated into the frames of the slides. The dimensions of lantern slides corresponded to the requirements of the projection apparatus they were designated for, ranging from one to three inches (2.5-7.5cm) in height for long slides produced for toy lanterns, up to ten inches (25cm) for slides for the custom-built lanterns of larger educational institutions.

Regardless of the slides’ intended use in performance, the technical production processes affected their formats as well. Painted slides, for example, required a certain size which allowed detailed craftsmanship in their painting. In the nineteenth century, typographic and photographic reproduction processes were introduced to produce lantern slides in large editions. This, in turn, impacted the image effect of those slides on the screen, which differed greatly from that of painted slides. Photographs initially enabled the transfer of smaller details onto glass than would have been possible by hand within the same dimensions, so drawings and painted images were also reproduced photographically and frequently hand-coloured. To rationalise production, manufacturers used similar cuts of glass for images and effects as often as possible, as well as uniformly manufactured wooden parts for the frames. This standardisation of dimensions particularly served to make production and distribution efficient.

Lantern slides were rarely produced exclusively for use by one particular institution, individual artist or showperson. The majority of surviving lantern slides are from the nineteenth century and were used in public performances for mass audiences by educational institutions and users who needed a large range of slides on various subjects for education and entertainment.⁵ Their demand guided the thematic and artistic choices of companies who commercially manufactured technically-reproduced lantern slides. Slides with moving mechanisms, slide carriers for use with slides in standardised formats and the optical lanterns offered for these applications were dimensioned to work with each other. This made it possible to use commercially available slides from different manufacturers with the same lantern and to freely and creatively mix and match slides in performance programmes. Surviving manufacturers’ catalogues and manuals outline a diverse range of distinct lanterns and slides.⁶ In addition, by around 1900 projection apparatuses were on offer which allowed films to be incorporated into the programming of a performance alongside lantern slides.⁷

Classification of lantern slides

The classification of surviving lantern slides in collections and archives is based on existing material artefacts, and particularly on the mechanical construction of lantern slides, techniques of image production and optical effects. The distinctive primary attribute for classification is the mechanical construction, while techniques of image production and optical effects are typically handled as additional features. eLaterna Archive and Lucerna record all classification criteria as metadata of both individual slides and slide sets.

The categorisation of slides serves to systematise surviving collections. Apart from the description of characteristics it also delivers information on the possibilities of the respective categories for the content, visual and dramatic design of the images which, nevertheless, were used with varying creative intentions. It is therefore useful, in order to describe and classify the material artefacts, to allocate the surviving slides to distinct types of moving mechanism. These are described in the basic element formats and mechanical construction of lantern slides. Examples from that text show that the same mechanisms were used for very distinct motion effects. Furthermore, similar motion effects were used for the composition of varying image contents and narrations. The individual investigation of a surviving slide explores the actual utilisation of options provided in the various categories, and is recorded as commentary in critical editions on eLaterna Archive.

The categories for the classification of lantern slides are generally named with reference to historic trade literature and manufacturers’ catalogues. The terms used in these stem from certain customs and differing conventions; their use is partly inconsistent. There is no verifiable historic formal standardisation of nomenclature. At present, however, the identifiers used in collections and archives enable a sufficient basis for communication.

There is still a need for etymological research to be done on the terminology of the history of the art of projection and the screen or, at the very least, glossaries referencing historic sources in a variety of languages.

4.1 Mechanical construction

An extensive classification scheme, which is mainly concerned with the (mechanical) construction of lantern slides, is widely observed by collectors. In 1990 film historian John Barnes published his classification of magic lantern slides for cataloguing and documentation in a publication of the Magic Lantern Society.⁸ His classification consists of 22 main categories which are further divided into 66 sub-categories. The categories refer to “lantern slides produced for the commercial market during the nineteenth century”⁹ but also include examples from the eighteenth century. In the main, they are well suited for descriptive recording and comparative documentation of surviving lantern slides in collections. However, Barnes’ chronological classification of which categories emerged in which periods of time has been partly superseded and no longer corresponds with the current state of research.

The documentation of lantern slides in eLaterna Archive and Lucerna lists the mechanical construction in the metadata under ‘format’. The basic element formats and mechanical construction of lantern slides outlines these categories. eLaterna Archive lists combined mechanisms under the format ‘combined mechanism’, with each element of the combination also recorded individually under ‘movement mechanism’.

4.2 Single slides and slide sets

eLaterna Archive differs decidedly from Barnes’ categorisation in the handling of the basic category ‘single slide’ (Barnes category D). Barnes’ commentary on his scheme described the single slide as “A single subject mounted in a wood frame”, supposedly introduced around 1830 but “eventually superseded by the Standard Slide”. In contrast, the basic element formats and mechanical construction forgoes chronological allocations and considers the single slide as a basic unit with diverse surviving versions, with standardised slides (Barnes category V) treated as one manifestation of single slides.

Temporal sequences of the visual occurrences on the screen from single slides are only realised through a succession of projected images. To achieve this, the slides are interchanged in the projection apparatus and the transition between the images is fashioned by visible exchange (for example shifting sideways with a slide carrier) or by dissolving. This process is described in the basic element optical projection effects. A predetermined combination of slides determines their temporal sequence in a performance. The combination may be determined immediately before a performance or by compilation of the slides in sets which are used for multiple performances in the same succession. Most surviving slide sets were compiled by manufacturers. In addition to the predetermined succession of images of a slide set, other slide formats introduce further temporal sequences through image motion, as described in the basic element formats and mechanical construction.

Techniques of image production

“To paint the picture right is the work whereupon rests the main importance; because no matter how well adjusted the lantern, and whether the cut glasses inside it are beautiful, if the images with all their colours do not appear lucidly and vividly on the wall, and are badly drawn as well, then you will not derive pleasure or profit from the expenditure.”¹⁰

This observation from the Oekonomisch-technologischen Encyklopädie by Johann Georg Krünitz conveys a pivotal experience of the art of projection by the eighteenth century: the processes of the image production and the quality of their execution on the slide determine the luminous images on the wall or screen. Krünitz’s comment on drawings and paintings is equally true for the typographic and photographic processes of image production and reproduction introduced in the nineteenth century which became the basis for the mass production of slides.

The slide images were applied to the transparent image substrate by painting, drawing, typographic processes or photographic techniques.¹¹ The metadata schemata of eLaterna Archive and Lucerna record these basic methods. More differentiated information, or rather research results, on the techniques of image production used may be elaborated on in the commentary on the surviving slides.

5.1 Image substrate materials

For a given intensity of the light source in an optical lantern, the luminosity and brilliance of the images on the screen is determined by the transparency of the paint application and the image substrate of the slide being used. No other material meets the requirements of a limpid image substrate as well as glass, which makes it easier to accept the serious disadvantage of the fragility of this material in contact with heat or mechanical force. However the application of binder, pigments and photographic emulsions to glass substrates requires considerable experience, and the cut glass plates need to show as few streaks and bubbles (which would be visible on the screen) as possible.

Other transparent image substrates such as mica or transparent paper were used far less frequently. From the beginning of the twentieth century, cellulose-based film material was also available to produce photographic or printed slides. After the development of the 35mm slide, film material dominated slide production in the second half of the twentieth century, until the advent of the currently common data projector in which the technical image information is digitally encoded and no longer visible itself. eLaterna and Lucerna record the image substrate in the metadata.

5.2 Image shaping and masking

In some surviving slides the shape of the image on screen is determined by the shape of the image substrate as fitted in the physical frame of the slide. The circular image of Lake Thun above is one example. In other cases, a format mask (or ‘mount’) is used to determine the shape of the screen image.¹² Optical projection effects such as dissolving views usually show the dissolving images within the same shape of exterior frame. Images superimposed on other projections typically leave only those parts of the image exposed on the slide which were intended to appear on the screen, with the rest of the image masked or covered in coating paint. eLaterna records the construction features ‘framing’ and ‘masking’ in the metadata.

5.3 Hand painted image techniques

A variety of methods of paint application were used in slide painting. Contemporary instructions primarily elaborate on the advantages and disadvantages of water and oil colour.¹³ Slides are also categorised as ‘painted’ when outlines and shades were applied with opaque colours or graphite pencil prior to the colouration with transparent colours. Drawings without colouration primarily served for illustration of educational topics, occasionally manufactured by the lecturers themselves.¹⁴

5.4 Print-based techniques

Different printing techniques allowed for the application of the same images to slides in technically unlimited numbers. Initially some hybrid processes combined the printing of graphic outlines with hand colouration – ‘copperplate sliders’, offered by the British optician Philip Carpenter from 1823, are regarded as the first commercially exploitable process of this kind.¹⁵ Their production was based on a technique similar to copperplate printing, for creating graphic outlines of the image which were transferred onto glass plates in quantity and then coloured by hand. Carpenter emphasised that the process ensured an invariably high quality of his depictions from natural history, history and other educational topics.¹⁶ Similar processes can be identified starting from the eighteenth century.¹⁷

‘Transfer slides’ represented a cheap method for the manufacturing of mass-produced full-colour lantern slides. For this technique, images were printed on to a paper substrate with colour printing techniques (such as chromolithography), then transferred onto the glass using various transparent binding materials, and finally the paper was removed.¹⁸ Transparent paper was sometimes also used as a substrate for printed images, bound between two cover glasses.¹⁹ A technical inventory and investigations of printing techniques used to produce lantern slides exists only rudimentarily.²⁰ For example there are no known investigations of slides printed on transparencies from the 1930s-40s, when they were used for educational policy and propaganda by the Nazi government.²¹

5.5 Photographic processes

From the mid-nineteenth century, photographic positives could be printed directly onto glass.²² The brothers William and Frederick Langenheim (Philadelphia 1849), and Daniel H. Briggs (Abington, Massachusetts 1850/51), are believed to be the earliest technical developers of photographic lantern slides who commercially exploited the slides themselves.²³ This invention was appreciated as a great advance compared to painted lantern slides: photography made it possible to provide comprehensive stocks of realistic slides on all educational topics. Furthermore, the photographs were characterised by the depiction of accurate details which afforded enormous magnification on the screen regardless of the small image area of a standard slide.²⁴

Various photographic processes were developed for slide making, for the reproduction of photographs, paintings and graphics. Since photographs were inherently monochrome, a variety of processes of hand colouring were also used.²⁵ An improper examination of these slides might lead to confusion between fully hand-painted slides and colourised reproductions of drawings and photographs. The image quality of photographs and the possibility of producing technically unlimited editions in a chemical technical process made photographic lantern slides the ideal basis to develop the art of projection as a mass medium.

5.6 Other image types

Real objects of an appropriate size may be projected directly, if they can be dissected translucently and bound between the cover glasses of a slide – known examples include insect wings and plant seeds. These objects take the place of the technical image information and transform into their own likeness on the screen. Krünitz mentions in 1794 that the magic lantern may thus function as a microscope.²⁶ For the projection of very small objects, projection microscopes were designed, and from the 1850s, these were also used to project microphotographs.²⁷ Various other accessories for projection apparatus, such as water-filled glass tanks (cuvettes) in which objects could be immersed or coloured dyes injected, were also developed to allow the immediate projection of scientific experiments and demonstrations.²⁸

Notes

1. ^{^} See Lester Smith and Stephen Herbert, “Formats, slides”, in David Robinson, Stephen Herbert and Richard Crangle (eds), The Encyclopaedia of the Magic Lantern (London: Magic Lantern Society, 2001) 116-117; Ruchatz (Note 29), p. 405-409. [xxx  -Ruchatz reference???]
2. ^{^} See Mervyn Heard, Phantasmagoria: the Secret Life of the Magic Lantern (Hastings: The Projection Box, 2006), 197-210.
3. ^{^} See Franz Paul Liesegang, Vom Geisterspiegel zum Kino. Vortrag zu einer Reihe von 66 Bildern (Düsseldorf: Liesegang, 1918), 31-35.
4. ^{^} A recording of a performance of this slide set is available on the DVD-ROM Lichtspiele und Soziale Frage. See Martin Loiperdinger and Ludwig Vogl-Bienek (compilers), Lichtspiele und Soziale Frage: Screening the Poor 1888-1914 (München: Edition Filmmuseum, 2011).
5. ^{^} See Ludwig Vogl-Bienek, Lichtspiele im Schatten der Armut. Historische Projektionskunst und Soziale Frage (Frankfurt am Main and Basel: Stroemfeld, 2016), 117-145.
6. ^{^} For a detailed overview see Walter D. Welford and Henry Sturmey (eds), The “indispensable Handbook” to the Optical Lantern: a Complete Cyclopaedia on the Subject of Optical Lanterns, Slides, and Accessory Apparatus (London: Iliffe & Son, 1888).
7. ^{^} Ludwig Vogl-Bienek, “Screening Sensations and Live Performance: the Creative Blending of the Traditional and New Projected Media at the Start of the Twentieth Century”, in: Kaveh Askari et al. (eds), Performing New Media, 1890-1915 (New Barnet: John Libbey, 2014), 217-226.
8. ^{^} John Barnes, “Classification of Magic Lantern Slides for Cataloguing and Documentation”, in: Dennis Crompton, David Henry and Stephen Herbert (eds), Magic Images: the Art of Hand-Painted and Photographic Lantern Slides (London: Magic Lantern Society, 1990), 75-84.
9. ^{^} Ibid., 75.
10. ^{^} Johann Georg Krünitz, Oeconomische Encyclopädie oder allgemeines System der Land-, Haus- und Staats-Wirthschaft, in alphabetischer Ordnung (Berlin: 242 volumes, 1773-1858); see particularly Vol. 65 (1794), 467. Online edition: www.kruenitz1.uni-trier.de (accessed 30 December 2017).
11. ^{^} See T.C. Hepworth, The Book of the Lantern: Being a Practical Guide to the Working of the Optical (or Magic) Lantern. With Full and Precise Directions for Making and Coloring Lantern Pictures (New York: Edward L. Wilson, 1889), 97-170; and [Paul Eduard Liesegang], Die Projections-Kunst für Schulen, Familien & öffentliche Vorstellungen (Düsseldorf: Liesegang, 8th edition 1882), 102-146.
12. ^{^} See Ann Hecht, “Masks (or Mats, Mounts), Slide“, in: Robinson, Herbert and Crangle (eds), Encyclopaedia, 189.
13. ^{^} See [Liesegang], Projections-Kunst, 114-127; Francisco Javier Frutos, “From Luminous Pictures to Transparent Photographs: The Evolution of Techniques for Making Magic Lantern Slides” in: Magic Lantern Gazette, vol. 25, no. 3 (2013), 3-11; and Janet Tamblin, “Slide Painting”, in: Robinson, Herbert and Crangle (eds), Encyclopaedia, 283-284.
14. ^{^} See [Liesegang], Projections-Kunst, 102-108.
15. ^{^} See Philip Carpenter, Elements of Zoology: Being a Concise Account of the Animal Kingdom, According to the System of Linnaeus (London: Rowland Hunter, 1823).
16. ^{^} Ibid., 1-5. For information on the production of ‘copperplate sliders’ see Ann Hecht, “Copper-plate Sliders”, in: Robinson, Herbert and Crangle (eds), Encyclopaedia, 77.
17. ^{^} See Willem Albert Wagenaar, Margreet Wagenaar-Fischer and Annet Duller, “Dutch Lantern Workshops“, in: Willem Albert Wagenaar, Annet Duller and Margreet Wagenaar-Fischer, Dutch Perspectives: 350 Years of Visual Entertainment (London: Magic Lantern Society, 2014), 39.
18. ^{^} See Ann Hecht, “‘Transparent’ Paper Slides“, in: Robinson, Herbert and Crangle (eds), Encyclopaedia, 308.
19. ^{^} See Ann Hecht, “Transfer Slides”, in: Robinson, Herbert and Crangle (eds), Encyclopaedia, 306.
20. ^{^} See Hermann Hecht, “Decalcomania: Some Preliminary Investigations into the History of Transfer Slides”, in: New Magic Lantern Journal, vol. 1, no. 3 (1980), 3-6.
21. ^{^} See Westermann Verlag, 2000 meist farbige Dia-Bilder (Braunschweig, Berlin, Hamburg: Westermann Verlag, 1942).
22. ^{^} See Stephen Herbert, “Photographic Slides”, in: Robinson, Herbert and Crangle (eds), Encyclopaedia, 232.
23. ^{^} Deac Rossell, “Langenheim, William and Frederick”, in: Robinson, Herbert and Crangle (eds), Encyclopaedia, 158-159; Deac Rossell, “Briggs”, Ibid., 45.
24. ^{^} See [Liesegang], Projections-Kunst, 1-2.
25. ^{^} See Jens Ruchatz, “Photographic Processes for Slide Production”, in: Robinson, Herbert and Crangle (eds), Encyclopaedia, 230-231.
26. ^{^} Krünitz, Oeconomische Encyclopädie, Vol. 65 (1794), 508.
27. ^{^} Stephen Herbert, “Lantern Microscope (or Projection Microscope)”, in: Robinson, Herbert and Crangle (eds), Encyclopaedia, 159; Stephen Herbert, “Microphotographic Projection”, Ibid., 193.
28. ^{^} See Lewis Wright, Optical Projection: a Treatise on the Use of the Lantern in Exhibition and Scientific Demonstration (London: Longmans, Green and Co., 1891), 145-146.