I have been urging for some years past that American education is seriously defective in that it provides an inadequate amount of training of the senses, particularly of the eye.
Charles W Elliot, Ph.D.
President-Emeritus of Harvard University, 1906 Introduction to Keystone's 600 Set Teachers' Guide
A gruesome scene certainly grabs attention (see Figure 1), but will gore help in training a student's senses--particularly in the way Dr. Elliot means in his introductory endorsement for Keystone's set of 600 educational lantern slides? The Keystone View Company must have thought so, because they selected a photograph showing three slaughtered hippos with wooden stakes holding their mouths agape as the picture advertising the company's educational 600 Set (see Figure 2).
"Magic lantern" was the name given to the first simple optical projection device created during the mid-1500s. This was before the development of the photographic process, so early lantern slides were miniature drawings or paintings on glass. Most early magic lanterns used a kerosene lamp as the illumination source, but the low intensity of a kerosene flame limited the use of the device to darkened rooms and restricted the projected image's size. Soon after, larger projectors capable of presentations to large theatre audiences were created. These "big image" magic lanterns used a hydrogen-and-oxygen gas flame aimed at a piece of lime to generate a powerful white light, giving rise to the name "limelight." Neither of the two types was suitable for classroom use; the first was too dim, the second too difficult to use. It was only after the invention of the electric light bulb as an illumination source that magic-lantern projectors became a practical addition to the classroom.
The name "magic lantern" sufficed during the years when it was a parlor entertainment device, but announcing to a class in the sciences that "today's lecture will be presented with the aid of a magic lantern" didn't sound terribly professional. Projectors advertised to educational institutions were given impressive high-tech aliases such as the Stereopticon, Balopticon, Delineascope, or Kinetoscope (see Figure 3). As impressive as the new brand names were, their renaming came too late. The "magic lantern" moniker had already become entrenched by more than a century's use, and most still call the projection devices magic lanterns. In fact, Turtox and other suppliers of biological materials called 35-mm projection slides or transparencies "lantern slides" in their biological supply catalogs until the early 1960s.
Giving a swanky name to the projector may have helped to raise the price, but more was needed to rouse the education community's interest in using the device as a teaching tool. That change required the availability of a large, inexpensively priced inventory of lantern slides. The Keystone View Company, manufacturers of home-use lantern-slide collections, jumped at the opportunity to fill that need.
* The Growth of the Keystone View Company
During the early 1900s, the Keystone View Company of Pennsylvania was the largest producer of stereoviews in the United States. These were flat cardboard cards printed with paired stereoscopic images and, in order to get a three-dimensional effect, viewed with both eyes through a two-lens viewer. The viewer was usually handheld and allowed only one person to see the picture at a time. Keystone View also made lantern slides for projection, which enabled group viewing. Many of the slides were made from one of the stereoview's paired negatives. Lantern slides were not stereoscopic but, being made directly from a film negative into a positive on glass by exposing a photosensitive emulsion, were sharper and had better tonal range than the stereoviews printed on photosensitized cardboard. B. L. Singley was Keystone's founder and original photographer, and, although he was competent enough to make a living by taking and selling photographs, he realized that salesmanship was his best talent. …