Transactions of the American Institute of Electrical Engineers, Volume 31

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American Institute of Electrical Engineers., 1912 - Electric engineering
"Index of current electrical literature" Dec. 1887-1890 appended tov. 5-7.

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Page 1024 - The author is disposed to adopt the hypothesis of an electrical plenum, and from the foregoing experiment it would appear that the transfer of a single spark is sufficient to disturb perceptibly the electricity of space throughout at least a cube of 400,000 feet of capacity...
Page 1023 - But be this as it may, the fact that the magnetic action of a current from a trough is at least not sensibly diminished by passing through a long wire, is directly applicable to Mr. Barlow's project of forming an electromagnetic telegraph ; * and it is also of material consequence in the construction of the galvanic coil.
Page 1021 - Professor Henry has been enabled to produce a magnetic force which completely eclipses every other in the whole annals of magnetism; and no parallel is to be found since the miraculous suspension of the celebrated oriental impostor in his iron coffin."* The first Electro-magnetic Engine.
Page 1225 - A considerable part (perhaps as much as onethird) of the energy delivered to the tube is transformed into heat at the point where the cathode rays bombard the target. Where platinum is used it has been found necessary, to prevent melting, to place the target beyond the focus of the cathode so as to spread the bombardment over a larger area. As a radiograph is a shadow picture, and as the source of the...
Page 609 - Divide the area by .7854 and extract the square root of the quotient ; the result is the diameter.
Page 616 - A," and the speed regulation of "D" is poor. STARTING WITH VARIABLE SECONDARY RESISTANCE Fig. 7 represents the conditions of speed, current, etc., when a variable secondary resistance is used at start. The motor starts at "F" on curve "D," and takes a current "G." The current falls to "H," while the speed rises to "i," which corresponds to the normal torque "T" at which the motor will run under the given conditions as long as the motor operates on curve "D.
Page 269 - The average load of 44,220 kw. was apportioned among the various roads operating in the city. (2) The results were increased, so as to apply to the Association of Commerce electric zone instead of the city limits. (3) A study was made of the movement of freight cars during the different hours of the day, and the different months of the year. The increased traction on account of cold weather was also considered. The daily, monthly and yearly load factors were thus obtained. (4) The maximum demand...
Page 1224 - Rontgen tube. With the advent of dense, forged pieces of pure malleable tungsten, the possibilities of the Rontgen tube are greatly extended. The desiderata in a material to be used as the anticathode or target are the following : 1. High specific gravity. 2. High melting point. 3. High heat conductivity. 4. Low vapor pressure at high temperature. The reasons why the above qualities are desirable follow readily from a brief consideration of the theory of Rontgen-ray production. From the concave cathode,...
Page 399 - I do not know that I can add anything to what has been already said in the text of the Lecture on this point.
Page 1225 - Roentgen tube is of the utmost importance, as the character of the rays is so largely determined by the vacuum. Metal, which under the influence of the high temperature vaporizes from the target, condenses on the glass in finely divided form and absorbs relatively large amounts of gas, thus changing the vacuum. At high temperatures tungsten vaporizes least of all the metals. Two distinct types of tungsten target are being tried out experimentally in competition with one another. The first of these...

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