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INDUSTRIAL AND ENGINEERING CHEMISTRY
phatic, acetylenes, olefins, esters, alcohols, and amines, for reduction (catalytic), elimination reactions, and the Mannich reaction, and could he located again in a search for any of these types of compounds or reactions. Figure 3 shows a reference which concerns the. synthesis of diaminoquinaldine and derivatives thereof for testing as trypanocidal agents. It has been punched for preparation, drug% 6-ring, condensed ring, A--hetero (making up the quinoline ring system), keto ester, hydroxyl, olefin, amide, salts, and polyamine across the top, and for alkylation, condensation, displacement, ring closure, and rearrangement reactions along the right side.
Vol. 42, No. 8
Figure 4 shows a card which has been punched for aliphatic, olefin, alcohol, acid, ester, and carbonyl compounde, as well as for spectra, quantitative analyses, and identification. LITERATURE CITED
(1) Casey, Bailey, and Cox, J . Chem. Education, 23, 495 (1946). ( 2 ) Cox, Bailey, and Casey, Chem. Eng. ~Vews,23, 1623 (1945). (3) Ferris, Taylor, Perry, and Torok, “Bibliography on the Uses of Punched Cards,” 2nd ed., AMERICANCHEMICALSOCIETY,
Punched Card Committee, 1949. RECEIVED December 29, 1949.
Hicrofilm Selection Equipment in Information Vork H. T. ENGSTROM Engineering Research Associates, Znc., S t . P a u l , ,Ifinn.
A microfilm selector in the library of the Department of Agriculture is capable of scanning 70,000 index entries per minute, and future equipment will strive for greater
I
T IS an axiom of well managed research that relevant information available in the literature should be studied and assimilated before a new project is undertaken. While bibliographic compilations (such as Chemzcal Abstracts and Engzneermg Abstracts) are very useful, the problem of locating all the relevant material on a given subject is a formidable one. The difficulties grow as the store of technical knowledge continues to increase. About 4000 hooks of scientific or technical importance appear each year, together 75ith over 7000 periodicals, of which over 50% relate to the chemical field. The problem is particularly acute in the present unsettled era, in which emergency conditions require that complex technological problems be solved with minimum delay. Rapid location of technical information is an important link in national defense. Difficulties in utilizing an ever-increasing store of knowledge have in the past profoundly influenced our basic methods of education. During the early years of this country’s history, educational procedure sought to cram into each individual mind as much information as possible. Gradually educational emphasis shifted from learning by rote to acquiring methods for locating desired information. As long as the total mass of technical information remained moderate in proportions, a search through a few standard textbooks and the indexes of a few journals of learned societies sufficed. K e have now entered another phase in which it is a major undertaking merely to inspect the information pertaining to a given subject. Getting a t desired information has become escessively expensive in terms of time and effort required on the part of skilled research personnel. MICROFILM SELECTOR
Fortunately, the same accelerated technological activity n-hich has created the problem has provided the means for its solution. Techniques developed in the fields of chemistry, optics, electronics, and photography have made it possible to construct equipment specially designed for ultrarapid searching of large masses of information. A particularly promising device is the microfilm selector, two somewhat different models of which have
adaptability. Experience indicates that equipment can be produced to meet the requirements of any coding method, proposed or foreseeable.
been constructed-the prototype developed a t the Massachusetts Institute of Technology by T’annevar Bush and a more recent model built by Engineering Research Associates, Inc., under contract with the Office of Technical Services of the Department of Commerce. The Department of Commerce machine, like the earlier Bush prototype, effects selection of desired items of information by photoelectrically scanning a specially prepared microfilm. An imaginary line running longitudinally down the film divides it into halves. On one half, the information, usually in abstract form, is entered on the film by the ordinary processes of microphotography. On the other half of the film, the successive index entries pertinent to this information are entered by coding each entry separately as a transverse double row of small opaque and transparent squares. The pattern of such squares within a double row signifies uniquely a single index entrv. I n operation, this master film is driven at a high rate of speed past an examining mask of black cardboard, in which holes are punched so as to provide a pattern n-hich is the inverse of that signifying the index entry being sought. When the pattern of the desired index entry is exactly matched by the searching mask--and only thenthe photocell scanning unit is momentarily blacked out. This actuates a flash photographv system which copies the associated item of information on an auxiliary reel of previously unexposed photographic film. Once a run is complete, the exposed section of the auxiliary reel is developed using well known methods. In this way, various items of information associated tTith any one index entry can be selected and photographic copies prepared on the auxiliary reel. The machine, in its existing form, scans some 70,000 index entries per minute. Tests have been made a t the library of the Department of Agriculture using a 2000-foot reel bearing 72,000 abstracts. Each abstract was accompanied, on an average, by six coded index entries. It has proved possible to scan this test reel completely in 6 minutes. All abstracts associated with any one index entry could be located without imposing any severe load on the electronics or mechanisms involved. With film of typical quality used by the motion picture i d u s t r y , the device operates in a thoroughly reliable fashion.
August 1950
INDUSTRIAL AND ENGINEERING CHEMISTRY
The microfilm selector at present located in the library of the Department of Agriculture is only typical of what can be done in general. Future equipment will undoubtedly strive for greater adaptability. Experience t o date clearly indicates that we are capable of producing today equipment of such flexibility as t o meet the requirements of any coding method yet proposed* or foreseeable at the present time. This means, in turn, that investigators of coding methods are in the fortunate position of being able to direct their attention to the intellectual aspects of the coding problem with full confidence that any necessary
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equipment can be constructed. Engineering Research Associates, Inc., already has under active consideration several new developments which it hopes to incorporate in future models. The time has now come t o take the next big step forward and t o produce a device of true flexibility. We are able to take this step now, even though we may not have completely formulated the logic of classification or the codification that ultimately will be used. R E C ~ I WSeptember D 30, 1949.
High-speed Electronic Clomputing Devices JAY W. FORRESTER Servomechanisms Laboratory, Massachusetts Znstitu.te of Technology, Cambridge 39, Mass. Machines now in existence or being built offer the possibility of revolutionizing the searching of scientific literature, if the necessary indexing-coding methods are
developed, though i t may take 10 years to develop abstracting and indexing procedures for general acceptance by the scientific and technical professions.
H
institute is studying the coding of scientific information for mechanized searching. It is expected that the two projects can be coordinated a t the proper time to use the high-speed computer for demonstrating the results of theoretical study. Leaving computing machines for the moment, we find t h a t obtaining the literature relevant t o some subdivision of a field of science involves two steps: (1) identifying documents of probable interest, and ( 2 ) physically obtaining the documents or their abstracts. The identification step, which in general is the more difficult of the two, could be mechanized by using digital computers.
IGH-SPEED electronic computers are capable of conducting clerical operations, provided the instructions are organized in an unambiguous logical fashion. Consequently, electronic computers offer promise of being applicable to routine searching of indexes and to similar bibliographical processing. The possibilities are best understood by observing that an analogy.exists between an electronic computer and a clerk using a desk calculator to process data entered in a notebook. The clerk corresponds to the central control element of the electronic computer, while the desk calculator and the notebook are, respectively, analogous to the electronic computer’s arithmetic unit and its external memory. Instructing an uninformed clerk in the routine to be followed is similar to programming the cycle of operations of the electronic computer. Although the machine performs its routine a t a rate of 1000 to 100,000 times as fast as a human operator, the instructions given to the central control unit are only an infinitesimal fraction (one hundred-thousandth or one hundred-millionth) of the memory cspacity of the human brain. The ability of the machine to exercise true judgment or t o learn by experience is correspondingly small. For all practical purposes, the memory capacity available to the machine in magnetic or photographic tape is practically unlimited. These three factors-speed, ability to exercise judgment, and memory storage capacity-will determine the ultimate usefulness of electronic computers for bibliographical purposes. The flexibility of electronic computers now under development should make unnecessary the design of special equipment for scanning and selecting scientific abstracts. Computers for research in library methods are becoming available as by-products of other engineering projects. One of the computers now being built is a t the Massachusetts Institute of Technology. This machine-sponsored by the Office of Naval Research-operates a t the ultrahigh speed of 10,000 to 20,000 arithmetic operations per second. The central control element is equipped with electrostatic storage tubes, having a capacity of 32,000 binary digits. Data from the photographic film memory unit can be received into the machine a t a rate equivalent to 3000 teletype characters per second. A Carnegie-sponsored project on Scientific Aids to Learning a t the
CODING THE MATERIAL
The critical operation in setting up machine searching is coding the material. The coding must be based on an index system not only compatible with the way a scientist will describe the material he desires but also capable of defining the search of the scope within wide limits. Only rarely will a person wish to have all the literature on phosphate compounds. Perhaps he is interested in their manufacture for fertilizer but wants only a general review, or he may want only detailed information on the manufacturing of superphosphates.. Or he may wish information on the use of phosphate fertilizer for growing corn in New England. It is clear that the coding must go far beyond the simple indexing found in card catalogs. For greatest effectiveness, the searching operation must take cognizance not only of what is wanted but what is not. Establishing the basic underlying pattern for machine coding will be no easy matter. I n setting up the code, provision must be made for changes in terminology and the development of new fields of science. Machines now in existence or being built offer the possibility of revolutionizing the searching of scientific literature, provided the necessary indexing-coding methods are developed. It may require 10 years or more to develop abstracting and indexing procedures sufficiently for general acceptance by the scientific and technical professions. The AMERICANCHEWICAL SOCIETY has already started such work and might well enlist the cooperation of other technical societies in this pioneering effort. RBCEIVZD M a y 3, 1950.
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