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.
.90 -DEGREE REFLECTORS
I Fig. 7. Portion of periphery of spinning disk showing form of mutually perpendicular reflectors and manner of mounting with notched retaining sectors.
RETAINING SECTOR
aphy of flame by the light which the flame itself radiates. Because securing adequate exposure densities is very difficult in direct-flame photography, some sacrifice in resolution appears justified.
In the second optical system, the two cylindrical lenses will be omitted. Although the resulting images will not conform exactly to the rotational surface of the moving optical parts, detracting somewhat from the quality of the resolution, a saving of approximately 15% of the light passing the objective lens will result. For the second optical system, the objective lens will be a Baltar, f/2.7, of 152-mm focal length. The first refocusing lens will be a CineDhor, //2.6, of 6.00-in. focal length. The second refocusing lens will be a Supercinephor, //2.0, of 2.75-in. focal .ength.
A suitable method for fabrication and mounting of the mutually perpendicular mirrors in the outer periphery of the spinning disk presented a perplexing problem. Figure 7 represents a portion of the periphery of the spinning disk showing the form of the mutually perpendicular reflectors and the manner of mounting with notched retaining sectors. This figure shows a wide slot in the peripheral surface of the disk, undercut at each side, in which reflecting prisms and prism-retaining sectors are mounted. As may be seen from the figure, the ends of the reflectors extend into the undercuts of the slot in the peripheral surface of the disk, and are
held in position by the aluminum retaining sectors which also fit into the undercuts. After assembly, each of the aluminum retaining sectors is secured in position by three No. 0-80 machine screws, which are locked by a drop of Glyptal on the head.
When the disk attains a speed of more than a few revolutions per second, centrifugal force drives each prism-type reflector firmly against its seat in the prism-retaining sectors. Each prismtype reflector, fabricated of a high-alloy steel, is polished and coated for high reflectivity on one surface only. The Vnotches were cut in the prism-retaining sectors with an accuracy of ±2 or 3 min of arc. As the reflecting surfaces themselves are driven by centrifugal force firmly against the notched surfaces in the retaining sectors, the 90° angle between the two reflecting surfaces of a pair is accurate within the same tolerance as that maintained for the V-notches in the prism-retaining sectors.
Although the arrangement of mounting of the 500 pairs of mutually perpendicular reflectors in the periphery of the spinning disk permits use of prisms having only one polished reflecting surface, the requirements for uniformity of dimensions in these prisms presented a rather difficult problem. Eventually, a remarkably easy solution to this problem was found, by which the prisms could be manufactured at a comparatively low cost and with extreme uniformity.
According to this method, the prisms
Miller and Scharf: Isotransport Camera
137