 They have a clear aperture of a square, half an inch in the side, and when held at right angles to the line of sight will separate the ordinary and extraordinary images to the amount of two inches, when the object viewed is held at seventeen inches from...  The British Journal of Photography - Page 2691878Full view - About this book
 | Science - 1878 - 802 pages
...The latest that I have had were procured for me by Mr. Tisley, optician, 172 Brompton Road. It has a clear aperture of a square, half an inch in the...sufficient for working with carte-de-visite portraits. One image is quite achromatic, the other shows a little color. The divergence may be varied and adjusted... | |
 | Anthropology - 1879 - 474 pages
...spar. The latest that I have had were procured for me by Mr. Tisley, optician, 172, Brompton Road. They have a clear aperture of a square, half an inch...when the object viewed is held at seventeen inches fiom the eye. This is quite sufficient for working with cartes-de-visite portraits. One image is quite... | |
 | Sir Francis Galton - 1883 - 434 pages
...Iceland spar. The latest that I have had were procured for me by Mr. Tisley, optician, 172 Brompton Road. They have a clear aperture of a square, half an inch...sufficient for working with carte-de-visite portraits. One image is quite achromatic, the other shows a little colour. The divergence may be varied and adjusted... | |
 | Francis Galton - Ability - 1883 - 422 pages
...Iceland spar. The latest that I have had were procured for me by Mr. Tisley, optician, 172 Brompton Eoad. They have a clear aperture of a square, half an inch...held at seventeen inches from the eye. This is quite COMPOSITE PORTRAITURE. sufficient for working with carte-de-visite portraits. One image is quite achromatic,... | |
 | Sir Norman Lockyer - Electronic journals - 1878 - 746 pages
...spar. The latest that I have had were procured for me by Mr. Tisley, optician, 172, Brompton Road. They have a clear aperture of a square, half an inch...the eye. This is quite sufficient for working with cartes-de-visite portraits. One image is quite achromatic, the other shows a little colour. The divergence... | |
 | Karl Pearson - 1924 - 570 pages
...used for optical superimposition is a 'double-image prism' of Iceland spar. The latest I have had has a clear aperture of a square half an inch in the side,...at right angles to the line of sight will separate ordinary and extraordinary images to the amount of two inches, when the object viewed is held at seventeen... | |
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