Edwin F. Northrup.
(published just after 1910)
Edwin Fitch Northrup was born at Syracuse, N. Y., Feb. 23,1866, where he attended the primary schools and after preparing for college at Cortland Normal School, Cortland, N.Y., entered Amherst College, Amherst, Mass., from which he was graduated with the degree of AB in 1891. While in Amherst he took an active interest in chemistry and philosophy and was one of the contributing editors of the Amherst Literary Monthly. Immediately upon graduation he entered the department of physics, in Cornell University as a special student, and worked in the university shops through the summer of 1891. Special courses in physics and mathematics were pursued and part taken, as an assistant to E.L. Nichols, in a research on "The Time Infinitesimal".
In the beginning of 1892 Dr. Northrup entered the employ of Queen & Company, instrument makers of Philadelphia, Pa. The company bad established an electrical laboratory at Ardmore, Pa., and was actively engaged in developing American designs of electrical measuring instruments. In connection with his work in this laboratory Dr. Northrup took out two patents and contributed frequently to the technical press, which led to his appointment as a fellow in physics under Prof. Henry A. Rowland at Johns Hopkins University. He entered upon his fellowship in 1893, and his thesis, an original investigation in electricity, was completed in his first year and appeared later in the Philosophical Magazine. He was re-appointed fellow the following year and received the degree of Ph.D. in physics in 1895.
Upon final graduation Dr. Northrup took charge for a short time of a six-mile electrical transmission plant of the "Monocyclic System", one of the first of its kind installed, which supplied electric power for the Ontario & Daly Mining Company, of Park City, Utah. He remained in Utah and Montana in miscellaneous practical electrical work until the fall of 1896, when appointment was accepted as head of the department of physics in the University of Texas, Austin, Tex. While occupying this chair he carried on an investigation of the transmission of inductive action, the results of which appeared in these columns in the issue dated Dec. 18, 1897, and invented the "Northrup Oscillating Current Galvanometer". He was re-appointed to the chair of physics, but left the university shortly after to enter the detail laboratory of the Westinghouse Electric & Manufacturing Company, where he was chiefly engaged upon the standardization and design of alternating-current instruments.
In 1898 Dr. Northrup was called from the Westinghouse Company to assist Prof. Henry A. Rowland in the development of his alternating-current multiplex printing-telegraph system, in which work he was engaged four years. After Professor Rowland's death, April 16, 1901, he was placed in full charge as chief constructing engineer of the Rowland Printing Telegraph Company. Under his direction there was constructed a set of machines for operation between Berlin and Hamburg, Germany, the mechanical design of which was almost wholly his own.
His work in connection with this telegraph system was recognized by the grant of a medal by the Paris Exposition of 1900. In 1902 he engaged with the Morris E. Leeds Electrical Instrument Company which in June 1903, was incorporated as the Leeds & Northrup Company, with Mr. M.E. Leeds as president and Dr. Northrup as secretary. This company developed rapidly and placed upon the market many electrical measuring instruments of novel design, including inventions covered by sixteen patents granted to Dr. Northrup.
In September, 1910, Dr. Northrup concluded to lead a more scholarly life in an environment where he would have better opportunities for study and research in the higher and more refined branches of electrical measurement, and accordingly accepted the proffered chair of assistant professor of physics in Princeton University, the Palmer Physical Laboratory offering exceptional attractions to one of his tastes. He intends to continue to devote himself exclusively to that side of engineering and science which pertains to temperature and electrical measurements, and in addition to his university duties will act as a consultant on these subjects.
Dr. Northrup's contributions to engineering science have been confined principally to methods and instruments for precise electrical measurement.
- The chief of these are an original form of ballistic galvanometer (1892), which received an award at the Chicago Fair;
- a portable dry cell (1893);
- oscillating current galvanometer (1897);
- inventions connected with the Rowland Printing Telegraph, especially means for maintaining synchronism, page printers, keyboards and long-pull magnets (1898-1901).
In the period from 1902 to 1908 his inventions include
- a four-coil decade system for resistance boxes;
- an alternating-direct-current comparator for alternating-current measurements;
- new designs of galvanometers;
- contributions to a new type of potentiometer;
- a line of resistance pyrometers;
- an electrical temperature recorder operating on a new principle;
- the working out of the law of pressure distribution in the interior of a conductor carrying current, and its application to an ammeter for the accurate measurement of currents above 1000 amp, direct or alternating;
- designs of indicating standardization wattmeters;
- a synchronizing tuning fork for the very precise speed control of small alternators.
Dr. Northrup has made numerous contributions to electrical literature, among which may be mentioned the following:
- A paper on "Dry Cells", Journal of Franklin Institute, March and April, 1893;
- "Specific Inductive Capacity", Philosophical Magazine, January, 1895;
- "A New Instrument for the Measurement of Alternating Currents", Transactions of the American Institute of Electrical Engineers, 1905;
- "Measurement of Temperature by Electrical Means", Transactions of the American Institute of Electrical Engineers, 1906;
- "Some Newly Observed Manifestations of Forces in the Interior of an Electrical Conductor", presented before the Physical Society and printed in Physical Review, June, 1907;
- "Conductivity and the Valuation of Electric Conductors", Electrochemical Industries, May 1909;
- "A New Type of Ammeter for the Accurate Measurement of Alternating Currents Above 1000 Amperes", Transactions of the American Electrochemical Society, 1909;
- "Cooling Curves and a New Type of Apparatus for their Autographical Ac Registration", Transactions of the Electrochemical Society, 1909;
- "The Comparison of Galvanometers and a New Type of Flat-Coil Galvanometer", Journal of Franklin Institute, 1910.
Dr. Northrup is a member of the American Institute of Electrical Engineers, fellow of the American Association for the Advancement of Science, member of the American Physical Society, member of the American Electrochemical Society and member of the Inventors' Guild.