Optic projection : principles, installation and use of the magic lantern, projection microscope, reflecting lantern, moving picture machine, fully illustrated with plates and with over 400 text-figures (1914)

Record Details:

Title:
Optic projection : principles, installation and use of the magic lantern, projection microscope, reflecting lantern, moving picture machine, fully illustrated with plates and with over 400 text-figures
Date:
1914
Author:
Gage, Simon Henry, 1851-1946
Publisher:
Ithaca, N.Y. : Comstock Publishing Co.
Volume:
Optic projection : principles, installation and use of the magic lantern, projection microscope, reflecting lantern, moving picture machine, fully illustrated with plates and with over 400 text-figures
Leaf #:
000491
Language:
English
Format:
Books
Contributor:
Gerstein - University of Toronto
Sponsor:
MSN
Coordinator:
Media History Digital Library
Description:
Bibliography: p. 693-703
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.

476 DIRECT CURRENT UNITS [Ca. XIII DIRECT CURRENT UNITS § 655. The Volt. — This is the unit of electromotive force, that is the electric force or pressure necessary to produce one ampere of current in a circuit with a resistance of one ohm. The difference of potential between the two poles of a Weston standard cadmium cell is i.o 19 volts. The ordinary battery used for ringing door bells has approximately one volt pressure. Voltage is a general term representing the pressure in volts in an electric circuit. If the difference of pressure between the two given points is great, then the voltage is said to be high; if the difference is slight, then the voltage is low. For example, in projection one might use 55 volts for the arc lamp, or 220 volts, or 500 volts. Ordinarily neither the low voltage of 55 nor the high voltage of 500 or 220 is used, but an intermediate voltage of no. § 656. The Ampere. — This is the unit of current. It is the current which will deposit .001118 gram of metallic silver per second from a 15% solution of silver nitrate in water. It is the current which one volt will maintain in a circuit with one ohm resistance (see below). Amperage is the term by which is designated the amount of current in amperes flowing at any given moment. If a large amount of current is flowing the amperage is said to be high or great, if a small amount, then it is said to be low or small. For example, in projection, the amFIG. 253. CONNECTIONS OF A VOLT , , . METER TO MEASURE THE ARC perage needed for drawing with VOLTAGE. the microscope on the house cir V VcTtnSer. cuit (§ 493) is small (3-6 am A Arc lamp. peres) , while for opaque pro R Rheostat. jection (§ 289), and for moving Note that the terminals of the volt J . ' . fe meter are connected to the two points pictures (§ 693) in large halls between which it is desired to measure the amount of amperage needed the potential difference. In this case . . . it is the two carbons (across the arc), is great (20 to 100 amperes ).