Article
Stanhope magnifying lens popular between 1860 and 1920
Charles Stanhope was born in London in 1753. He was a well-regarded statesman and had a considerable interest in science. Because he was a wealthy man and very philanthropic, he aided not only his own scientific investigations, but also those of other inventors.
Editor's Note: Collecting items of ophthalmic interest is part of our ophthalmic heritage. What follows is an article about collecting Stanhopes, artifacts that occupy but a "small" area of our ophthalmic past.-Norman B. Medow, MD, FACS
One of his personal inventions carries his name, the Stanhope lens. This small magnifying lens was used in the textile industry to count the numbers of cotton fibers in a field. The lens was used well into the end of the 1800s. Its most popular use was in the making of peeps or optical viewers. The lens consists of a glass rod with one flat polished surface located at the exact focal length of the spherical convex surface at the other end. Stanhope died in 1816, long before the most popular use of his lens would be established.
In 1859 René Dagron, a microphotographer in France, was suffering from the same problems as Dancer was in England. After seeing a Stanhope magnifier, he developed the idea of mounting microphotographs on a miniature Stanhope lens. The images were fixed to the flat surface of the lens using a clear optical cement called Canadian Balsam. This is the same balsam that was used in bifocal segment cementing for many years.
Documenting war Dagron became very successful and used these microphotographs to document the Franco-Prussian War in 1870. Dagron was ingenious not only in documenting the war with microphotographs but in the way he sent them to Paris; he used carrier pigeons! After the war Dagron developed a thriving business using images of the United States, Europe, and the Holy Land as the primary images for his tourist attraction.
John Tull, MD, is a retired ophthalmologist as well as author, collector, and historian. He is a board member of The Museum of Vision at The Foundation of the American Academy of Ophthalmology. He is a member of the Stanhope Collectors Club.This vignette is an edited, abbreviated version of the article that appeared in Scope, Fall 2001;vol. 5, issue 3:7-12.
Norman B. Medow, MD, FACS, editor of Ophthalmic Heritage, reviewed this column. He is director of pediatric ophthalmology at Manhattan Eye, Ear & Throat Hospital, and Chair of the Museum of Vision at The Foundation of the American Academy of Ophthalmology.
