Bausch & Lomb Optical Co. (Rochester, NY)

Alvan G. Clark Lens, 1888-c.1890's

Scovill & Adams Co. catalog, June 1891, pp. 67-68


The Gauss Lens was invented by Carl F. Gauss in 1817 as an improvement to an astronomical objective for refractor telescopes,  The Gauss Lens consists of two elements (one positive and one negative) having a thin air spacing.  In 1888, Alvan Graham Clark convinced Bausch & Lomb Optical Co. to produce a Double-Gauss Lens for photography.  The Double-Gauss, marketed as the Alvan G. Clark Lens, combined two Gauss lenses arranged symmetrically in the barrel.  Alvan G. Clark was the son of the founder of Alvan Clark & Sons, an optical company that manufactured  astronomical lenses.  Their specialty was refracting lenses (as contrasted to the reflecting mirror lenses that dominate large telescope objectives at present).  Alvan Clark & Sons, among others, made the 36" lens at Lick Observatory, and the 40" lens at Yerkes Observatory, still the largest refracting telescope in the world.

Alvan G. Clark, having grown up with telescopes, was an famed astronomer of the day.  He found the first documented instance of a white dwarf star, Sirius B, the companion to the bright star Sirius.  His fame allowed him to suggest the lens to B&L, and likewise, his fame allowed B&L to market the lens as an improvement.  Unfortunately, the lens reportedly was not much better than the already available rapid rectilinear lenses that were common and less expensive.  The basic lens design, but with more complex groups, has been used for 35mm lenses by such notables as Leica and Nikon.

Bausch & Lomb Optical Co. Photographic Objectives, Shutters and Accessories, Bausch & Lomb Optical Co. (Rochester, NY), 1898, pp. 42-43
The International Annual Anthony's Photographic Bulletin, Vol. III, 1890-1891, W. J. Harrison and A. H. Elliot, eds., E. & H. T. Anthony & Co. (New York, NY), ads p. 95
How to Make Photographs and Descriptive Price List, The Scovill & Adams Co. (New York, NY), distributed by Horgan, Robey & Co. (Boston, MA), June 1891, pp. 67-68
How to Make Photographs and Descriptive Price List, The Scovill & Adams Co. (New York, NY), distributed by Horgan, Robey & Co. (Boston, MA), January 1892, pp. 69-70
The International Annual of Anthony's Photographic Bulletin Vol. VII 1895,E. & H.T. Anthony & Co. (New York, NY), 1894, ads p. 54
Catalogue of Photographic Apparatus, Rochester Optical Co. (Rochester, NY), May 1897, p. 76
Illustrated Catalogue of Photographic Equipments and Materials for Amateurs, E. & H.T. Anthony & Co. (New York, NY), February, 1898, p. 51

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