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alternating current amperes anode armature arranged ball break capacity cells chapter circuit breaker coil giving condenser conductor connected Crookes tube Crookes vacuum tube desirable developed direct current discharge terminals disk double focus tube elec electric current electric light circuit electrical discharges electrified electrode Elihu Thomson exciting apparatus experimenter exposure fluorescence fluorescent screen fluoroscope glass hand high frequency apparatus high frequency transformer high potential Holtz machine inch spark induced current induction coil inductive effects initial charge insulation kind known light rays lines of force magnetic metal obtained operated ordinary photographic plate placed platinum practical primary coil produced radiograph ray experiments ray phenomena rays of light reader rheostat rotary contact breaker Ruhmkorff coils secondary coil secondary terminals sensitized plate single focus tube small motor spark gap static machine storage battery surface tinfoil type of apparatus type of tube usually volts Wimshurst Wimshurst Machine X rays
Page 116 - A wide field of concrete investigations is open here for the social scientist, investigations which are important not only from the theoretical but also from the practical point of view; for the manipulating of symbols, whether for persuasion or propaganda, requires at least a clarification of their intrinsic structure.
Page 23 - ... sliding a cardboard or rubber cover over the latter. Now we will place it on a table, lay a hand upon the covering of the plate and produce the X rays by means of a suspended Crookes tube. In a few moments the electric current is stopped and the plate taken away and developed. Upon printing this- we find that part of the plate not covered by the hand is a clear white. We also find that the X rays have penetrated entirely the muscles, and to a great extent the flesh, blood and nails, leaving only...
Page 11 - Society. 441 with the wonderful difference that the new rays would penetrate flesh, blood, muscle, cloth, wood and many other substances which are opaque to ordinary rays of light. For years he had been studying the action of currents of electricity in glass tubes more or less •exhausted of air, known as the Geissler, Crookes, or vacuum tubes. Like the electric current, he found the rays...
Page 22 - We will wrap it in black paper or enclose it in a plate holder, sliding a cardboard or rubber cover over the latter. Now we will place it on a table, lay a hand upon the covering of the plate and produce the X rays by means of a suspended Crookes tube. In a few moments the electric current is stopped and the plate taken away and developed. Upon printing this- we find that part of the plate not covered by the hand is a clear white. We also find that the X rays have penetrated entirely the muscles,...
Page 119 - Ruhmkorff coil, the terminals of the two cups are connected together and then connected with the cathode, or negative terminal, of the coil. The terminal of the wedge-shaped electrode is connected with the positive, or anode. When the current from the coil is discharged through the tube, the two cathodic streams bombard the platinum wedge, and the two cathode electrodes being cupshaped, the cathodic rays are focussed to a point and strike the anode upon each side.
Page 53 - Condenser consists of a number of sheets of tinfoil separated from each other by means of wax paper.
Page 178 - The film side can always be ascertained by holding the plate sideways towards the red light. The film side is dull while the other side of the plate, being plain glass, has a bright and shining appearance. If still in doubt, the film side can be detected by moistening a finger and touching one corner of the plate. If the film is on that side, it will feel sticky.
Page 147 - The plate may be placed either in an ordinary plate-holder, which should be closed in the regular manner with a slide (not of metal), or the plate may be wrapped up in a piece of photographer's black paper, with sufficient folds to exclude light both from the sides and the ends.
Page 24 - Thus we can to-day obtain pictures of the bony structure of any part of the body and show the presence not only of foreign substances of a metallic nature, but also of calcareous deposits or other substances that are opaque to the X rays.