- FAQ

Sir David Brewster

Sir David Brewster
Sir David Brewster
  Sir David Bewster was born  on December 11th, 1781, in Jedburgh, Roxburghshire, Scotland and died on February 10th, 1868, in Allerby, Melrose, Roxburghshire, Scotland

Scottish physicist noted for his experimental work in optics and polarized light--i.e., light in which all waves lie in the same plane. When light strikes a reflective surface at a certain angle (called the polarizing angle), the reflected light becomes completely polarized. Brewster discovered a simple mathematical relationship between the polarizing angle and the refractive index of the reflective substance. This law is useful in determining the refractive index of materials that are opaque or available only in small samples.

Brewster was educated for the ministry at the University of Edinburgh, but his interest in science deflected him from pursuing this profession. In 1799 he began his investigations of light. His most important studies involved polarization, metallic reflection, and light absorption. He was elected a fellow of the Royal Society in 1815, and he invented the kaleidoscope the following year. He was knighted in 1831. In the early 1840s he improved the stereoscope by utilizing lenses to combine the two dissimilar binocular pictures and produce the three-dimensional effect. Brewster was instrumental in persuading the British to adopt the lightweight, flat Fresnel lens for use in lighthouses. In 1838 he became principal of the United College of St. Salvator and St. Leonard of the University of St. Andrews and in 1859 became principal of the University of Edinburgh.

Of Brewster's numerous published works, his Treatise on Optics (1831) and Memoirs of the Life, Writings and Discoveries of Sir Isaac Newton (1855) are probably the most important. 

Sir David Brewster was an outstanding scholar who had the distinction of going to Edinburgh University at the age of eleven. He was elected a Fellow of the Royal Society in 1815, was a founder of the British Association for the Advancement of Science, and was responsible for numerous inventions. He did early work on the properties of light, and the kaleidoscope. He was in touch with Fox Talbot and it was he who suggested the use of the photographic process to David Hill, as an aid to his painting. He clearly favoured Talbot's Calotype process over the Daguerreotype. 

"While a Daguerreotype picture is much more sharp and accurate in its details than a Calotype, the latter possesses the advantage of giving a greater breadth and massiveness to its landscapes and portraits... 

In point of expense, a Daguerreotype picture vastly exceeds a Calotype one of the same size. With its silver plate and glass covering, a quarto plate must cost five or six shillings, while a Calotype one will cost as many pence....

The great and unquestioned superiority of the calotype pictures is their power of multiplication. One Daguerreotype cannot be copied from another, and the person whose portrait is desired must sit for every copy that he wishes.

When a pleasing picture is obtained, another of the same character cannot be reproduced. In the Calotype, on the contrary, we can take any number of pictures, within reasonable limits, from a negatives; and a whole circle of friends can procure, for a mere trifle, a copy of a successful and pleasing portrait. 

In the Daguerreotype the landscapes are all reverted, whereas in the Calotype the drawing is exactly conformable to nature..

The Daguerreotype may be considered as having nearly attained perfection.... whereas the Calotype is yet in its infancy..."

In 1849 Brewster invented the Lenticular Stereoscope, a viewer for stereoscopic prints. These became popular items in Victorian drawing-rooms. His book (The Stereoscope, its history, theory and construction) is still a good introduction to stereoscopic photography, though the author rather spoilt it by his unpleasantries concerning Wheatstone, who had actually invented stereoscopy. 

Please do not forget to visit the Bookshop, offering the world's largest selection of books in 3D and about 3D.
Learn More Click Here to Pay

Button left Back to the FAQ Page

Last modified on May 4, 2005
Copyright © 1999 - by and Alexander Klein. All rights reserved.