capacity, power-factor, and dielectric loss. Full results and test data are given in form of tables and graphical charts. Discussion, pp. 1021-1025, by Messrs. Henry W. Fisher, Charles P. Steinmetz, E. W. Stevenson and Henry G. Stott. General remarks on dielectric properties of cables. S. B. Fortenbaugh CONDUCTOR RAIL MEASUREMENTS Vol. xxvii-1908, pp. 1215-1229 Results of tests on Metropolitan District Railway third and fourth rail conductors, giving leakage and insulation difficulties under various conditions of service; also complete data on resistance tests made on conductor rails. No discussion. HIGH-POTENTIAL UNDERGROUND TRANSMISSION P. Junkersfeld and E. O. Schweitzer Vol. xxvii-1908, pp. 1499-1527 Description of the underground cable system of the Commonwealth Edison Company of Chicago with records of its performance and results of experiments to determine the magnitude and frequency of occurrence of potential rises in the system. Discussion, pp. 1528-1569, by Messrs. L. A. Ferguson, Charles H. Merz, H. W. Fisher, H. G. Stott, E. J. Berg, Wallace S. Clark, Alex Dow, Warren Partridge, E. E. F. Creighton, L. T. Robinson, Henry Floy, John W. Lieb, Jr., Philip Torchio, Charles P. Steinmetz, E. O. Schweitzer, Peter Junkersfeld, Ralph D. Mershon, H. W. Peck, A. E. Kennelly, N. J. Neall, L. L. Elden, M. V. Ayres, G. W. Palmer, Jr., and Dugald C. Jackson. Cable experience of various large central stations and transmission companies. Vol. xxviii-1909, pp. 363-393 THE CONVECTION OF HEAT FROM SMALL COPPER WIRES A. E. Kennelly, C. A. Wright and J. S. Bylevelt Experimental investigation of convection from wires-varying diameter, air pressure and wind velocity. Discussion, pp. 394-397, by Messrs. V. Karapetoff, Charles P. Steinmetz, Charles F. Scott, Paul M. Lincoln and A. E. Kennelly. Remarks on nomenclature for absolute units. RESISTANCE AND REACTANCE OF ARMORED CABLES J. B. Whitehead Vol. xxviii-1909, pp. 737-746 Calculation and tests of effective impedance and reactance of single and double-conductor iron and copper-armored cable under various conditions of current density, spacing, interconnection of armor and sheathing, etc. Discussion, incorporated with that of Mr. H. W. Fisher's paper on "Losses, Induced Volts and Amperes in Armor and Lead Cover of Cables." LOSSESS, INDUCED VOLTS AND AMPERES IN ARMOR AND LEAD COVER OF CABLES Tests of impedance, reactance, resistance and induced current and volts in the sheath and armor of single-conductor iron-armored, copperarmored and steel-tape armored cables, showing the effect of spacing, current density, cross-bonding of sheath and armor, etc. Graphical method of calculating the performance of such cables. Discussion, pp. 766-767, including the discussion of Mr. J. B. Whitehead's paper on "Resistance and Reactance of Armored Cables," by Messrs. Ralph D. Mershon, H. W. Fisher, John B. Whitehead and Charles P. Steinmetz. General discussion of the advisability of using single-conductor cables in alternating-current power transmission. Harold S. Osborne POTENTIAL STRESSES IN DIELECTRICS Vol. xxix-1910, pp. 1553-1581 General résumé of work done in developing graded insulation for cables with derivation of formulas and construction of various sets of curves from which the best designs for graded cables can be read directly. Analytical discussion of phenomena immediately preceding dielectric breakdown- -corona on solid dielectrics-giving opinions of many eminent authorities, followed by a suggested explanation which is checked by tests. Bibliography. Discussion, pp. 1582-1624, by Messrs. J. B. Whitehead, Milton Franklin, A. E. Kennelly, W. S. Franklin, W. I. Middleton, Henry A. Morss, R. W. Atkinson, H. W. Fisher, Percy Thomas, C. J. Fechheimer, G. I. Rhodes, Armin Henry Pikler, C. P. Steinmetz, C. O. Mailloux, Tracy D. Waring, William A. Del Mar and H. S. Osborne. General discussion of graded insulation as applied to cables, generators and transformers, and also of the phenomena that precede breakdown in solid dielectrics. Formulas and experimental results bearing on the design of insulation. Effect of grading on the maximum safe kilowatt capacity of cables. 6. MAGNETIC PROPERTIES AND TESTING OF IRON THE FACTORS WHICH AFFECT THE ENERGY LOSSES IN ARMATURE CORES J. Walter Esterline and C. E. Reid Vol. xxii-1903, pp. 445-460 Description of apparatus for experimental investigation of armature core losses. Analysis of core losses and results of tests showing effect of teeth, core section, solid poles, laminated poles and other factors on such losses. Discussion, pp. 461-466, by Messrs. J. W. Esterline, Henry Pickler, W. E. Goldsborough, W. S. Franklin, Leonard Wilson, C. O. Mailloux and A. E. Kennelly. Effect of number of poles and of pole arc upon armature core losses. MAGNETIC PROPERTIES OF ELECTROLYTIC IRON F. C. Burgess and A. Hoyt Taylor Discussion, pp. 466-471, by Messrs. E. F. Northrup, D. C. Jackson, Chas. F. Scott, W. L. R. Emmett, C. P. Steinmetz, C. F. Burgess and R. A. Fessenden. Magnetic alloys that do not contain iron. THE EFFECT OF IRON IN DISTORTING ALTERNATING-CURRENT WAVE FORM Frederick Bedell and Elbert B. Tuttle Vol. xxv-1906, pp. 671-691 Theoretical investigation of the relation between the third harmonic introduced by iron in the exciting current and the hysteresis loop. Also, an exposition of the relation between the area of the hysteresis loop and the angle of hysteresis advance. Discussion, pp. 692-714, by Messrs. Chas. P. Steinmetz, Philip Torchio, W. S. Franklin, Frederick Bedell, Harold Pender, A. Henry Pikler, S. P. Grace, H. B. Tuttle, S. N. Kintner and A. W. Copley. Full discussion of wave distortion due to iron, showing that other harmonics than the third modify Professor Bedell's conclusions. References to early work of Huguet, Froelich, Kennelly, Gerosa, Finzi, Eickemeyer and Steinmetz. Effect of wave distortion with different polyphase transformer connections. Derivation of the parabolic law of magnetic induction. Oscillograms of induced e. m. f. showing effect of primary impedance on wave form in core loss tests and in transformers. THE TESTING OF TRANSFORMER STEEL M. G. Lloyd and J. V. S. Fisher apparatus. Analysis of core losses and results of tests on large variety of transformer steels. Discussion, pp. 468-473, by Messrs. L. T. Robinson, V. Karapetoff, C. E. Skinner, J. C. Lincoln, Clayton H. Sharp, Andrew Pinkerton, E. E. F. Creighton and M. G. Lloyd. Discussion of the relative value of Bureau of Standards method and the Epstein method for commercial testing. Relation of magnetizing current to transformer regulation. CALCULATION OF IRON LOSSES IN DYNAMO ELECTRIC MACHINERY I. E. Hanssen Vol. xxviii-1909, pp. 993-1001 Experimental study of stream lines in various types of armatures, with a simple method for pre-determining the total iron loss. Discussion, pp. 1002-1004, by Messrs. R. E. Hellmund, A. E. Averett, V. Karapetoff and I. E. Hanssen. Remarks on the accuracy of the author's method. POLE-FACE LOSSES C. A. Adams, A. C. Lanier, C. C. Pope and C. O. Schooley Vol. xxviii-1909, pp. 1133-1156 Theoretical and experimental investigation of pole-face losses, establishing quantitative relations between such losses and the principal variables for both solid and laminated pole shoes. Comparison of calculated losses with test values. No discussion. 7. BATTERIES Arthur E. Kennelly THE NEW EDISON STORAGE BATTERY Vol. xviii-1901, pp. 219-230 Description of the battery, its advantages and mechanical construction. Performance data obtained from Mr. Edison. Discussion, pp. 231-246, by Messrs. A. E. Kennelly, N. S. Keith, Charles P. Steinmetz, Robert McA. Lloyd, Carl Hering, C. O. Mailloux, H. G. Stott, Justus Entz, Charles J. Reed and H. E. Heath. Principal disadvantages of the nickel-iron cell. Further performance data. H. P. Coho THE STORAGE BATTERY AS A FACTOR IN SPEED CONTROL Vol. xx-1902, pp. 135-138 Brief description of electric drive for Hoe printing press, using storage battery for multi-voltage. Discussion, incorporated with that of paper by F. O. Blackwell on "Continuous Current Motors for Machine Tools." POINT OF CUT-OFF IN A BATTERY DISCHARGE Carl Hering Vol. xix-1902, pp. 325-331 Considerations which enter into the determination of proper point of cut-off of discharge for primary and secondary batteries. Graphical solution. Typical discharge curves for constant current, constant resistance and constant power. Discussion, incorporated with that of paper by W. R. Whitney on "Colloids." STORAGE-BATTERY INDUSTRIAL LOCOMOTIVES Vol. xxii-1903, pp. 109-123 F. L. Sessions General discussion of storage-battery locomotives-their advantages; methods of operating the battery; calculation of battery rating for given service; motor control, etc. Tables for facilitating the calculation of storage-battery rating, with numerical example illustrating their use. Discussion, pp. 124-131, by Messrs. Edgar H. Berry, F. L. Sessions and Elmer A. Sperry. General remarks on storage-battery performance in industrial locomotive service, and criticisms of author's tables. THE STORAGE-BATTERY IN SUBSTATIONS W. E. Goldsborough and P. E. Fansler |