OCTOBER 15, 1939
ANALYTICAL EDITION
(14) Liebisch, T., and Rubens, H., Sitzber. preuss. Alcad., 16, 198, 876 (1919). (16) Mattauch, J., Sitzber. Akad. Wiss. Wien Math.-naturw. Klasse. Abt. I I a , 145,461 (1936). (16) Mattauch, J., and Herzog, R., 2. Physik, 89, 786 (1934). (17) MBnch, G., and Willenberg, H., Ibid., 77, 170 (1932). (18) MiFller, R., IND.Em. CHEM.,Anal. Ed., 11, 1 (1939). (19) Pfund, A. H., J . Optical SOC.Am., 29, 291 (1939). (20) Randall, H. M., and Firestone, F. A., Rev. Sci. Instruments, 9, 404 (1938). (21) Schaefer, Clemens, and Matosei, Frank, “Das Ultrarote Spektrum”, p. 213, Berlin, Julius Springer, 1930. (22) Scott, Howard, J.Franklin Inst., 220,733 (1935). (23) Smiley, C . H., Popular Astronomy, 44, 415 (1936). (24) “Spectroscopy in Industry, Conference”, New York, John Wiley &Sons, 1939.
(25) (26) (27) (28) (29) (30) (31) (32) (33) (34) (35) (36) (37) (38)
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Stockbarger, D. C., Rev.Sci.Instruments, 7, 133 (1936). Stromgren, B., Vierteljahrschr. Astronomischen Ges., 70,65 (1935). Strong, John, Astrophys. J., 83,401 (1936). Strong, John, “A New Radiation Pyrometer”, in press. Strong, John, J . Optical SOC.Am., 26, 73 (1936). Strong, John, Phys. Re$.,36, 1663 (1930). Strong, John, “Procedures in Experimental Physics”, Chap. 111,New York, Prentice-Hall, Inc., 1938. Ibid., Chap. V. Ibid., Chap. VIII. Ibid., Chap. X. Strong, John, and Brice, R. T., J . Optical SOC.$m., 25, 207 (1936). Tillyer, E. D., Ibid., 28, 4 (1938). Willenberg, H., Z . Physik, 74, 663 (1932). Wimmer, Max, Ann. Physik, 81, 1091 (1926).
Coordination between Instrument Maker and Research WILLIAM H. REYNOLDS, American Instrument Company, Silver Spring, M d .
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HE close integration that may exist between instrument maker and research laboratories is well illustrated by the experience of this company. The men who founded the organization 25 years ago were skilled technicians who had been associated exclusively with experimental groups. It was natural, therefore, that their independent activities should from the start have consisted in the construction, according to sketch or published paper, of fine instruments and equipment for governmental, educational, and industrial laboratories, Many published contributions have rested strongly on a specialized apparatus carefully constructed by this establishment. This policy of close contact and collaboration with organized research groups, although greatly extended and varied, has remained essentially the same through the years. In a large new plant, generously equipped with standard and highly specialized tools, construction proceeds a t any one time on a number of different instruments designed to fill special research needs. Scientists from governmental laboratories and from schools in the vicinity of Washington, D. C., frequently avail themselves of facilities not to be found elsewhere. The present new plant has 20,000 square feet of floor space. The organization is divided into several closely knit sections, the principal ones being the technical and development section and the fine tools division. The rapid tempo of scientific development requires incessant scrutiny and study of the literature and contact with leading laboratories. New instruments and new designs of old instruments find their fitting counterpart in new materials of construction, machines, and methods. Skill, resourcefulness, and economy of manufacture alone no longer suffice to meet the demands of an exacting scientific world, but the fabrication must be guided by and conform to inexorable theoretical requirements. This aspect is taken care of by the highly trained technical section, which is closely integrated with the production department. It is not unusual for the construction of an instrument and its proper employment to be conditioned by exacting mathematical relationships, Coordination with and service to chemical and physical research laboratories are, however, hardly complete if they stop a t the point of making specialized instruments. The plant and skills of the organization are therefore directed toward the manufacture of standard instruments and routine laboratory equipment. I n all these operations the same type of skilled mechanic is employed as in the special instrument con-
struction. The standard apparatus is mainly for testing, for control, and for analysis, and fabrication is of metal, glass, or other material.
Services It may be thought that the product of an instrument company is nothing more than a home-made gadget in fancy dress. This is far from being true. Into each instrument enter desirable and indispensable values that result from much thought, planning, combined skills, and the application of special tools and methods. The product of a reputable instrument company will give more accurate, rapid, and certain measurements and results than the comparative makeshift of the hurried and unspecialized laboratory worker. A case recently came to notice of the loss of time and ruination of experimental work caused by a home-made thermoregulator. The construction seemed relatively easy, but unexpected difficulties of fouling of the mercury, breaking of the thread, etc., arose which are to be contrasted with the simplicity, reliability, and accuracy of, for example, a metastatic thermoregulator. Besides offering substantial improvements over home-made equipment, a further type of service consists in the production of instruments and apparatus that the average shop is scarcely equipped to make. An example is the preparation of fused glass absorption cells with guaranteed plane parallel ends, which requires highly specialized skill and tools. A third type of service consists in a more economical and efficient construction than is possible in the average laboratory, yet with a t least equal accuracy. Recently the company was faced with the task of constructing a respirometer according to a published design. It was found possible after suitable consideration to prepare a very much simpler piece of equipment which functioned the same and just as effectively; the simplifications cut the cost considerably, and resulted, in fact, in putting the instrument on the general market. A further contribution of value consists in making generally available, very shortly after publication or announcement, instruments and equipment that have obvious merit. There have been several instances in which a demand for an instrument, promptly proclaimed after publication, was just as promptly met. In this way the findings and accomplishments of research laboratories come into general use a long time, years perhaps, before they would without the service rendered by the modern instrument company.
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The company has found it desirable to sustain cooperative fellowships and research undertakings in connection with instrumentation. Two such are in operation at present. The main objective of one of these has been to develop the most scientific method of use and most efficient design of an important instrument for fine size analysis, which is manufactured by the company. This fellowship has been unusually fruitful and has resulted in fundamental findings. The second research is in the automotive industry and has to do with the study of the various conditions of use of engine indicators so as to develop their widest utility. costs
The undeserved penalty of good appearance is sometimes the impression that the cost has been polished up, so to speak. As far as established instrument making is concerned, this is not true, nor can it be under competitive conditions. The notion may be based on a hurried and fallacious method of accounting. One cannot estimate the cost of an instrument, any more than anything else of use value, on the basis of the value of the component materials. There are items to be
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considered of initial technical investigation, experienced engineering design, and skilled machine construction, all of which lead to a more efficient, more durable, and more presentable article than in the absence of these services. One need hardly mention also the usual economic items of capital investment, obsolescence, overhead, salary, etc., which should be taken into account when an investigator attempts his own construction. Finally, one may note the saving of valuable time and effort, as far as the real objective of the investigator is concerned, when he has before him a highly satisfactory instrument, ready for use. In conclusion, the instrument maker is interested in the problems of the investigator and research worker. I n fact, he has to be, for it is only on the basis of the broadest knowledge of the requirements of the laboratory that he is able to render a fitting service. I n this sense, he welcomes the inquiries and interest of the investigator, and he is prepared fully to cooperate with him. The scientific research world has been implemented thereby in a manner that has created more accurate results and broadened research horizons beyond the fondest dreams considered possible only a few short years ago.
Spectrograph Design and Its Problems J. W. FORREST, Bausch & Lomb Optical Co., Rochester, N. Y.
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PTICAL instruments of various kinds are extremely valuable in chemical analysis. Microscopes, colorimeters, polarimeters, saccharimeters, and refractometers are extraordinarily useful tools for the identification of unknown substances or for the determination of the degree of concen-
STEINHEIL SPECTROGRAPH OF 1894
tration of known substances. They are valuable for the kind of information they may supply, for the speed with which required information may be obtained, and for the degree of accuracy obtainable in comparison with other methods. While comparisons are dangerous, one is tempted to say that the spectrograph is more usefuI to the chemist than all the abovementioned instruments. It is deplorable that there is no word which includes both spectroscope and spectrograph. I n spite of the fact that the spectrograph with its permanent photographic record of both visible and invisible portions of the spectrum is the most commonly used, the spectroscope is too useful to be ignored. The reader should interpret the word “spectrograph” in this article to include spectroscope and spectrometer unless it is obvious that only the photographic form is meant. For years the spectrograph was the physicist’s most powerful tool in his search to unravel the secrets of the construction of matter, and unaided i t led him to the necessity for recognizing orderly arrangement in the complex structure of the atom. Lockyer in 1873 for the first time advanced the theory that changes in line spectra, due to rise in temperature of the source, could be explained by the breaking up of the atom just as the transition from band spectra to line spectra may be explained by the dissociation of the molecule. The chemist soon recognized its power to reveal the composition of unknown materials and the astrophysicist made i t his basic instrument. It has revealed the fact that the universe is apparently made up of the same chemical elements that compose the earth. Without the spectrograph it is impossible to imagine how we could have acquired any information whatever about the composition of heavenly bodies except what might have been gleaned from the occasional meteors which reach the earth. Matter, emitting or absorbing radiation which the spectrograph can analyze into its component wave lengths, reveals not only its identity but much about the state in which i t exists. Distance is immaterial, provided enough light reaches the observer to affect the eye or the
