Living pictures; their history, photoproduction and practical working. With a digest of British patents and annotated bibliography (1899)

Record Details:

Title:
Living pictures; their history, photoproduction and practical working. With a digest of British patents and annotated bibliography
Date:
1899
Publisher:
London Optician & Photographic Trades Review
Volume:
Living pictures; their history, photoproduction and practical working. With a digest of British patents and annotated bibliography
Leaf #:
00029
Language:
English
Collection:
Books
Format:
Books
Contributor:
Robarts - University of Toronto
Sponsor:
University of Toronto
Coordinator:
Media History Digital Library
Description:
52
Date Added:
July 19, 2022
Something wrong or inaccurate about this page? Let us Know!

Thanks for helping us continually improve the quality of the Lantern search engine for all of our users! We have millions of scanned pages, so user reports are incredibly helpful for us to identify places where we can improve and update the metadata.

Please describe the issue below, and click "Submit" to send your comments to our team! If you'd prefer, you can also send us an email to mhdl@commarts.wisc.edu with your comments.




We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.

Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.

DIAGRAM ILLUSIONS. 11 Faraday also pointed out that one wheel gave the same result if revolved in front of a mirror, the image taking the place of the second wheel; the advantage secured being that speed of object and image were bound to be absolutely identical. It was but a step from this discovery to the employ- ment of a disc pierced with slots to look through and bearing radial lines on its face, i.e. the side to be turned towards the mirror. From this experiment strange results followed. When the slots were equal in number to the radii (Fig. 7), the image (as seen through the slots and in the mirror) ap- peared stationary; when the slots were slightly fewer than the radii, the wheel appeared to travel slowly forw^ard (z>. in the same direction as the real motion of the disc) and to move in the backward direc- tion if the slots outnumbered the radial marks. Now it must be understood that the disc is revolved so rapidly that if the image be viewed directly [i.e. not through the slots) the black spokes would be confused into a gray circle. Yet when seen through these small openings every individual spoke appears distinctly, a fact which points out the slots as the key to the mystery. The reason is simple. Every time a slot passes the eye an impres- sion is received of the image of the whole face of the disc (as seen in the mirror), and though the whole image is turning rapidly, the slot (if narrow) goes so quickly past the eye that the image has not time to move far enough to give any impression of motion, and therefore Fig. 7.