The Holmes Stereoscope

Not only was the Holmes Stereoscope priced to be available "within the range of all classes," as claimed by the Illustrated London News, it was probably the most effective stereoscope ever produced. The British photographer, Valentine Blanchard, discovered a Holmes scope that had been left behind at a seaside hotel by an American tourist. So impressed was he with the instrument that he imposed on a British manufacturer to copy the American design with the addition of a detachable stand as shown in the model above. In its original form, the Holmes scope was hand-held by way of a retractable handle mounted near the viewer end of the focus adjustment bar. The stereograph slots between two metal clips mounted on a cross-rail, focal length can be adjusted by sliding the rail along the bar (seen slotted into the stand in the illustration above). As Valentine noted, the arrangement allows for a much greater degree of focal adjustment than did the mechanics of its contemporary stereoscopes such as the Pedestal or Brewster models.

The design of the Holmes stereoscope, with its comparative portability, was to become the blueprint for later pocket stereoscopes such as the Rotoscope and the modern View-max.