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: Hybrid measurementSara Hillnhuetter By the 1830s, in other words, before photography attracted public attention, measuring techniques based on light-sensitive scales were already in existence. For example, the weather researcher Thomas B. Jordan developed a device to measure light in processes known in their early years as photology or photometry.1 His daylight recorder was used to illustrate hours and intensity of sunshine. The first additional value transmitted by means of light was temperature. The measurement of three-dimensional figures became a matter of routine much later and was mainly used by the military and by astronomers, geologists, and weather researchers whose targets were amorphous, ephemeral, or difficult to access. When daguerreotypes were first presented in 1839 at the Académie des Science, François Arago noted that the depicted objects were projected bundling together in the vanishing point of a lens, a geometric zero, creating the conditions for the measurement of the depicted volumes on the surface.2 But it was not until the 1850s that the practice of measurement by means of photography was given a specific name and routine by Aimé Laussedat (métrophotographie), Pio Paganini (fototopografia), Albrecht Meydenbauer (Photogrammetric).3 Some of the naming is translated into English, but most of the practices go by the term photographic survey or how Charles Sanders Peirce called it photometry.4 All these practices put standard mathematical methodology and photographic techniques to the test, by measuring non-geometrical objects, for example, clouds.5 The more chaotic side of the new medium characteristics was described by a further protagonist of early photography history: In 1833, Henry Fox Talbot traveled to Lake Como, where he completed a drawing of Villa Melzi, noting that he only reproduced the outlines. “Such, then, was the method [...] to trace with my pencil the outlines of the scenery depicted on the paper”.6 His dissatisfaction with the result caused him “to reflect the inimitable beauty” of the light projection in the camera obscura. He wanted an image replete with all details and indifferences of contour and memorizable form. Upon his return, as he described in Pencil of Nature, he began to experiment with light-sensitive emulsions in order to record the “fairy pictures, creations of a moment, and destined as rapidly to fade away”.7 Talbot’s title Pencil of Nature evoked many references in scholarly research on photographic recording where his publication is taken as an example of the replacement and dismissal of manual techniques of visualization.8 But the hybridity of the image is actually in the ordering practice between artifact and fact. In order to derive measurable figures from the array of photographic appearances, it was indispensable to focus the device on the objects in such a manner as to deliver clear contours. In his article about John Herschel and his photographs of the Orion nebula, Omar Nasim quotes Isaac Roberts that it had been essential to have photographs depicting planets as spherical objects in order to access the optional new information from the photographic plate. That meant to connect the already known characteristics of the planet being formed round by gravity to match with their flat appearance. Nasim goes on to argue that drawing was a means of dealing with the complexity of the photographic image. Rudolf Stichweh attributed the advent of precision measuring devices to the cultural desire for complete recordings, which he argued was based on two developments: First, an extreme intellectualization of the experiment and precision measurement, which seems to be trying to escape the unavoidable materiality of instrument use in the second stage. Secondly, a refusal to accept uncertainty and nescience. It is obvious that every use of technology and every development of technology are accompanied by an inescapable ignorance regarding several of the conditions on which a technology is based.9 Both geometry and wealth of detail as the two poles of photographic characteristics were crucial to the various photographic approaches aimed at recording amorphous, unnoticed, or unknown aspects and abstracting them into geometric figures. The desire for completeness and infinite detail drove many of the early players in photography to fix images in order to subject them subsequently to a variety of methods and examinations, of which measurement was one option. In that sense, the use of photography represents a paradigm shift in the long history of measurement,10 because no longer was the object itself measured, rather a picture of it.11 Usually, early photography was a struggle over the correct depiction of a figure, as Nasim already illustrates. Taking measure is therefore a hybrid practice by itself since it develops meaning within distance to the object, what makes the produced knowledge always discussable. In his case study on Theodor Scheimpflug, Michael Kempf demonstrates that professional measurers, the geodetists, were not impressed with the idea of working from a photograph. They continued to prefer the theodolite, an optical angle measuring instrument. The data harvested from observation were directly transferred to a map on paper in an already abstract form. Talbot’s fairy pictures, which portrayed identically, made the geodetists skeptical by their indifferent appearance. Kempf shows how Scheimpflug bolstered his arguments in keeping with the rhetoric of his times, with the broadly stressed neutrality of photography. The article weaves together the different levels of scientific-historical analysis and examines how a technical invention fails by the way it is described and presented. In measurement practice seems to stand as an acid test to appropriating and evo-cating reality by means of photography. Photographed objects gain a second life that takes place independently of their physical existence and can change that very existence. This is clearly demonstrated by Sigrid Schulze’s chapter about the brothers Schlaginweit. Not only did they photograph the Alps, they built a model of them with a view to photographing them again. Like Herschel by drawing the stars in their constellations, the Schlaginweits captured the complexity of the situation with a manual Hybrid measurement 9 model. By photographing it again, they hid the synthetic nature of the object behind the materiality of photography and gave their work an authentic-objective character. Usually, in addition to measuring, photography had a second function in the respective disciplines: the division of time and movement, the scaling of objects, and the structuring of the observation. Finally, Sara Hillnhuetter discusses how images taken by the Preussische Messbild-Anstalt to measure buildings were also used in art history. The art and architecture historians no longer debate the usefulness of the images with regard to their mathematical evaluation, rather their vividness. Through measurement, certain body schemata, which art historians had covered with the principles of perspectives, had been reduced by the photographic process to the extent that the architecture appeared autonomous from its urban context. The text mainly focuses on the lack of unity among the players as to whether the buildings were depicted “correctly”. The case studies show that each upcoming photographic technique contains different relations as productive and reproductive picture to other media, before or after them. Homi Bhabha describes this principle with the term hybridity, with which he marks that the effect of the images still lies in between and cannot be wide apart in a specific direction. He sees the difference of photography especially in the depiction of the absent, which makes it necessary to resume searching and going places: “The dynamic of displacement emphasises the importance of the iterative and interstitial”.12 In that sense the players have to compensate the absence of the depicted object. By doing so they all operate with expectations and knowledge of a collective kind to which they want to add something. The following chapter presents how materiality, techniques, and symbols merge into a concept of “the photographic”. Leaning toward this question, measuring stands for the attempt to find a precise, technical routine between the materiality of the object and its picture, but the genesis of knowledge begins with the reflection about intermingling visualization materialities and further begins with the dealing of expectations already. Notes
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