College and Research Libraries Re-Evaluation of Microfilm As a Method of Book Storage BY VERNER W. CLAPP AND ROBERT T. JORDAN EVER SINCE THE INTRODUCTION of micro- film into library work librarians have harbored the hope that its use might lead to a reduction of storage costs. These hopes have not been realized, ex- cep~ in_ certain high-rental areas by or- ganizatiOns such as law offices or some special libraries. From time to time esti- mates have been made comparing the cost of conversion to microfilm as against that of retaining originals, and these have always come out in favor of the originals unless some additional consid- e~ation was introduced, such as acquisi- tiOn, preservation, or avoidance of the cost of binding. A ~articularly important study of this question was reported by Pritsker and Sadler1 in 1957 in an article whose title has suggested that of the present account. These authors concluded that "On a cost basis, microfilm is feasible as a form of storage for a large collection only if li- brarians are willing to accept a high re- ductio~ ratio, little or no inspection of the finished product, an image less per- fect than could be obtained by using a 35mm. planetary camera, and the de- struction of the text. If a positive copy of the film is required, the cost of micro- film storage is prohibitive."2 However, the Pritsker and Sadler arti- ~le left some unanswered questions. Most Important, perhaps, of these was: What would happen if the cost of the master negative should be shared among a num- ber of subscribers to service copies? Would this so alter the situation that 1 _Alan B. ~ritsker and J. William Sadler, "An Eval- uation of M1crofilm as a Method of Book Storage " CRL, XVIII (1957), 290-296. ' 2 Pritsker and Sadler, op. cit., p. 296 . JANUARY 1963 Mr. Clapp is President of the Council on Library Resources. Mr. jordan is a member of the staff of CLR. microfilming might be able to compete successfully, on a cost-of-storage basis, with the originals? The announcement by an important research library of its intention to limit the storage space in its new building in the prospect of being able later to micro- film as economically as to construct addi- tional book stacks3 recently provided the occasion for reviewing the situation in the light of present techniques of ·micro- filming and present costs of construction of storage space, and also for considering the possible effect of distributing the cost of the master negative among a number of subscribers to service copies. The following elements were consid- ered in this review: The cost of making the master negative The cost of making service copies The number of subscribers Comparative costs of constructing stor- age space for the originals and for the microfilms Not considered in the review were the following elements: The comparative cost of maintenance (heating, lighting, cleaning, etc.) of the storage spaces involved The comparative costs of servicing col- lections in original and in micro- form, including specifically the cost 3 Herman H. Henkle, "Crerar Use of Microfilm in Science Information Service," National Microfilm As- sociation Proceedings, X (1961), 74-78. 5 TABLE 1 CHARACTERISTICS OF HYPOTHETICAL CoLLECTION oF BouND PERIODICALs Number of volumes . Average number of pagesj volume Total pages Most often occurring page size . Maximum page width 100,000 400 40,000,000 ca. 8Y2 x II in. 11.5 in. Portion of the collection meeting requirements for cover-to-cover copying at standard camera settings . 70% Portion requiring page-by-page inspection to determine alternative settings for magnification or exposure or use of color film . 30% 1% 10% Portion to be filmed in color cover to cover Portion to have an average of 5% of pages in color Portion requiring lower than standard reduction ratio (any material requir- ing lower reduction setting would be copied on entire-volume basis on separate camera) 10% of special equipment needed for servicing micr~film The comparative costs of necessary al- terations of catalog records The comparative cost and satisfaction to the reader in the use of originals as contrasted with microfilm Questions of copyright in the multipli- cation of service copies THE FoRBEs AND WAITE STUDY In order to secure data on the cost of making the master negative and service copies of a substantial collection of orig- inals, Forbes and Waite of Lexington, Massachusetts, a firm of systems engi- neers specializing in information systems design including photographic applica- tions, was given by the Council on Li- brary Resources the assignment of esti- mating the cost of microfilming a hypo- thetical collection of 100,000 bound peri- odical volumes by the most economical method consistent with preserving all the printed information contained in the originals in a form in which it might be transmitted without material loss to the third photographic generation (i.e. , from the master negative film to a service copy, and thence again to another copy in film or enlargement). This stipulation for preserving "all the printed information contained in the originals" involved the consequence that originals printed in color should be copied on color film. In making their study Forbes and Waite were permitted to plan to reduce the cost of the master film by using methods that would result in the destruction of the origi~al volumes, and to spread the cost of the master through the sale of service prints to a number of subscribers. It was understood, furthermore, that in no case might the negative be used as a service copy. Before presenting Forbes and Waite's findings it may be well to review some of the considerations which affect the cost of a microfilming program of this kind, and to follow the steps by which Forbes and Waite reached their results. I. Standard microcopying. The negative microfilm of a quality acceptable for li- brary use is normally produced from ma- terial in book form by employing a planetary camera (typically, a camera supported by a vertical column over a horizontal copy-board), a book cradle and glass pressure plate (to effect flatness of the pages to be copied), and 35mm. silver halide film. A first question concerns the form of the product. Is roll film the best form of storage? Forbes and Waite consider the alternatives-microfiches (film in card or page sizes), microcards, electronic re~ord­ ing on plastic, electronic recording on 6 COLLEGE AND RESEARCH LIBRARIES magnetic tape, etc. They conclude that of the available means, roll film still offers the most economical form of stor- age for graphic records and the one lend- ing itself to utmost convenience of use through currently or prospectively avail- able viewing, copying, or enlarging equipment. However, the cost of the normal copy- ing process described above is so high as to put it out of the running in competi- tion with the cost of storing the original. Because the major part of this cost is in labor, a first place where savings must be effected if competition is to obtain is in labor cost; an9 this must be done with- out lowering the quality of the product below standards of acceptability. 2. Page-turning devic es. A substantial labor saving might be achieved if an automatic book-cradle/page-turner were available which would make it possible for one operator to supervise several cameras concurrently. The only such de- vice is, however, only now undergoing · testing. 3. Shearing spines. It is nevertheless still possible to effect a considerable labor saving in the photographic operation by avoiding the necessity for raising and lowering the pressure plate each time a page is turned. This can be done by shearing the spines from the books so that the pages may be laid separately on the copy board where they will lie flat without a pressure plate. The adoption of this technique of course requires that the bound volumes be destroyed. Forbes and Waite were permitted to assume the dispensability of the volumes and con- sequently propose to shear the spines. 4. Inspection. A next possible step in labor saving consists in omitting inspec- tion. Pritsker and Sadler gave six excel- lent reasons to justify omission of in- spection, yet librarians generally . would be strongly opposed, since it would place too much reliance upon the unchecked attentiveness of the camera operator and upon the perfect functioning of his equipment. Accordingly, Forbes and Waite assume inspection. 5. Silver halide vs. other films. At this point attention may be given to saving cost of materials. Is a silver halide film required for the master negative, or can a less expensive photosensitive material be used? Principal objections to alterna- tive photosensitive materials are their slowness and their sensitivity in the ultraviolet. In the present state of the art, Forbes and Waite conclude that there is still no real alternative to silver halide film. 6. 16mm. vs. 35mm. film. It may, how- ever, also be asked, is 35mm. film re- quired by the size of the image, or may a higher ratio of reduction be employed, permitting the use of 16 mm. film (or its equivalent, two rows of images on 35mm. film, as in the "duplex mode" used by some rotary cameras)? (It may be noted that black and white 16mm. film costs approximately a fourth of 35mm. film for the same amount of material copied, TABLE 2 COMPARATIVE DIRECT COSTS , PRODUCTION OF MASTER NEGATIVE OF 40 MILLION PAGES OF BOU ND PERIODICALS BY V ARIOUS METHODS Tim e I R"ulHn g Resulting Camera set-up required Film rolls of rolls of (years ) b&w film color film All planetary cameras (6) 5.25 16mm. 19,162 485 Hand-fed rotary cameras (2) with planetary 20,702 auxiliaries (2) . 4 .00 16 mm . 485 Automatic-feed rotary camera (1) with plane- tary auxiliaries (2) 4.00 35 mm. 11 ,774 600 (duplex mode) JANUARY 1963 Direct cost $3 32,372 263,183 271,445 7 while for color film the savings are even higher.) The answer to this question de- pends on the ability of 16mm. film to meet the requirement of preserving "all the printed information contained in the originals." The resolving capability of the human eye at comfortable reading distance is approximately six lines per mm. If the de- tail which the eye can perceive in the original is to be preserved in the camera negative and to be transmitted to second and third generations of film, the camera negative must be capable of resolving a number o~ lines per mm. at least equal t? the ratiO of reduction multiplied by SIX. For example, material reduced at a ratio of 1: 19 would require a resolution of 114 lines per mm. in the negative film. The lens must of course have at least equal resolving power. Now an ll-inch- high page can be copied across a 16mm. fil_m (i.e., with the lines of type parallel With the edges of the film) at a reduction of 1: 19, and since the resolving power of the be~t comll_lercially available plane- tary ~Icrofilming equipment is 120 to 140 hnes per mm. at this ratio of reduc- tion, this layout is indicated. To quote F~rbes and _Waite: "This arrangement will allow side-by-side placement of se- quential pages, will accommodate fold- outs of ~ny length, and will permit pho- tographing two standard-width pages at each exposure when printing occurs on both sides of the leaves (the usual case)."4 A~ the same time this arrangement per- mits use of a lower reduction of 1: 14 for pages higher than 11 inches (and for oth- e~ pages uns~itable for the higher reduc- tiOn) by copying them lengthwise instead of across the film. Film cost could, it is true, be further saved by the use of still higher reduction ratios. Ratios of 1:30 to 1:40 are used in filming business records, but the result- ing films, as in the case of bank checks, 'Forbes. and. Wait~, . Costs and Material Handling Pro~let?ts 1n Mm~atunz~ng 100 ,000 Volumes of Bound Per~od~cals; rep::tred for the Council on Library Re- ~~~~;;s(pr~~ess:d)~gton, Mass.: 1961. 30 p., 13 folding are for purposes of verification only and are ~ot required to convey "all the print- ed Information in the originals." East- man Kodak's Minicard uses ratios up to 1:60~ but ~equires a whole family of speCial equipment for its exploitation. AVCO's Verac and National Cash Regis- ter's Photochromic Micro-Image Memory employ ratios up to 1: 200; but these are still under development. Yet the use of th~se higher ratios, if found possible, might result in substantial reduction of the cost of microfilming through saving of materials and processing, and the pos- sibility, must, in consequence, not be neglected. 7. Rotary cameras. Once a decision has been made to shear the spines off the books and to use 16mm. film, can a fur- ther economy be achieved by using a rotary instead of a planetary camera, thus greatly reducing the labor cost and speeding the operation? Forbes and Waite give a qualified positive answer. The Recordak rotary camera Model RF -1 will turn a page over and photo- graph the reverse side on a second pass. Although the machine must be hand-fed ~h~n t~is turning device is in operation, It IS still approximately three times as fast as a plane~ary camera. However, there are two adverse considerations- the tun~ing mechanism is not 100 per cent reliable, and the resolution of the syste~ rarely exceeds 100 lines per mm. and IS often below. Forbes and Waite recommend that before this camera be used it be perfected for the work. Recordak and Remington Rand both make rotary cameras which can be op- erated with automatic feed in the "du- plex mode," i.e., they photograph the fronts and backs of pages side-by-side in two rows on 35mm. film. However, such a placement would be very inconvenient for projector viewing or subsequent en- largement, and would also entail the use of the more expensive 35mm. film for the color and other abnormal material to be copied on a planetary camera and spliced into the machine-made film. Forbes and 8 COLLEGE AND RESEARCH LIBRARIES • TABLE 3 DIRECT COSTS, PRODUCTION OF MASTER NEGATIVE OF 40 MILLION PAGES OF BOUND PERIODICALS, USING PLANETARY CAMERAS, AND 16MM. FILM, 5.25 YEARS Operation Equipment I I Equipment I Production I Equipment maintenance rate (per cost (per year) man /hour) Direct labor I Supplieo I Total Inventory check . - - - 180 vols. $1,315 - Transport 12 book trucks $900 $90 114 vols. 1,184 - Preinspection 2 photometers 900 90 6.25 vols. 32,000 $100 2 work places 300 30 Shearing of backs 1 paper cutter 1,800 360 25 vols. 9,000 40 1 work place 300 30 Microfilming 5 planetary 11,700 570 375 expo- 120,800 57,733 cameras sures (2 for b&w pages/ex- posure) - - 1 planetary 2,340 117 75 exposures - - camera (1 page/ex- for color posure) 6 work places 900 90 - - - Film processing & splicing 1 film 2,275 228 2 rolls 26,500 3,947 processor 1 temperature 600 60 control 3 splicers 450 45 25 splices - - 3 work places 450 45 Postinspection, boxing and labeling 3 microfilm 3,600 180 1500 pages 40,200 - readers Storage . I ,680 feet of 2,360 100 - - - shelves or cabinets Capital investment . $28,875 . Labor, supplies . $230,999 $61,820 Annual costs, 5.25 years $2,035 43,999 11,775 $57,809 Total, capital investment and costs, 5.25 years Waite do not recommend this type of camera for use in the project considered. 8. Nonstandard material-preinspection procedure. The economy of the film- ing operation requires that routines be standardized. However, a certain propor- tion of the material will require special- ized treatment. This must be identified by preinspection which will note special JANUARY 1963 $332,372 requirements based on abnormal page or type size, paper color and reflectance, ink color, density of impression, bleed- through, overprint, and need for color reproduction. Color work would in any case be done on a separate camera, and if a rotary camera were employed for the standard treatment, all alternative treat- ment would have to be performed on 9 TABLE 4 DIRECT CosTs, PRODUCTION oF MAsTER NEGATIVE oF 40 MILLION PAGES oF BouND PERIODICALS, UsiNG HAND-FED RoTARY CAMERAS AND AuxiLIARY PLANETARY CAMERAS WITH 16MM. FILM, 4 YEARS Operation Equipment I I Equipment I Production I Equipment maintenance rate (per cost (per year) man/hour) Direct labor I Supplies Total Inventory check . - - - 250 vols. $ 1,000 Transport . } r 900 $ 90 150 vols. 900 - Preinspection Same as 1,200 120 6.25 vols. 32,000 $100 Shearing Table 3 of backs 2,100 390 25 vols. 9,000 40 I Microfilming 2 rotary 4,214 422 1,250 expo- 58,278 61,930 cameras sures (2 pages/ex- posure) 2 planetary 4,680 234 225 expo- - - cameras sures (1 page/ex- posure) 4 work places 600 60 - - - Film processing & splicing 2 film 4,550 455 2 rolls 21,500 3,532 processors 2 temperature controls 600 60 ·. 3 splicers 450 45 25 splices -- - 3 work places 450 45 Postinspec- } Same as { tion, box-ing and Table 3 labeling . . 3,600 180 1,500pages 40,200 - Storage . 1,820 feet 2,555 100 - - - of shelving or cabinets Capital investment . $25,899 . $162,878 $65,602 Labor, supplies . Annual costs, 4 yrs . . $2,201 40,719 16,401 $59,321 Total, capital investment and costs, 4 yrs. auxiliary planetary cameras. Forbes and Waite recommended that the preinspec- tors rotate in the postinspection job so as to · see the results of their work. 9. Seroice copies. Pritsker and Sadler w(!re compelled for economy's sake, as seen in their conclusion quoted above, to contemplate the use of the camera negative as a service copy. Forbes and $263,183 Waite were not permitted to do so, but were encouraged, instead, to seek econ- omies through prorating the cost of the negative in the sale of service copies to a number of subscribers. Again they sur- veyed all the possibilities for the form of the service copies, and again they elected roll microfilm. Again there was a choice between silver halide and the dye-base 10 COLLEGE AND RESEARCH LIBRARIES TABLE 5 CoMPARATIVE DIREcr CosT, PRODUcrioN oF SERVICE PRINTS oF 40 MILLION PAGES OF BOUND PERIODICALS BY V ARlO US METHODS Print material DIRECT COST ' Quantity 1 print 10 prints Diazo• :} $24,920 $226,700 Silver 2 x 106 feet of black and white 16mm. film 36,692 366,920 Kalfax 43,867 398,950 Kodachrome . 48,500 feet of 16mm. color film 7,553 75,530 *As pointed out above, diazo has a life·expectancy of approximately 50 years. The amount of $3,507 added to the original cost and compounded annually at 4 per cent woulri in 50 years realize $24,920 to replace the original print. films. For the purpose of service prints, however, the slowness and ultraviolet sensitivity of diazo are not as disadvan- tageous as in the case of the camera nega- tive. In addition to its lower cost, a diazo print would itself be a negative from which positive third generation prints or enlargements could be made and which would provide negative projection-view- ing which many consider preferable to positive-viewing. It has higher resolv- ing power and resistance to wear than the silver films. Consequently, although it has a life-expectancy of only fifty years, Forbes and Waite recommend it. Also they point out that in fifty years the difference in cost at 4 per cent compound interest would increase to 3.6 times the cost of the original diazo print and thus more than cover replacement. THE FORBES AND WAITE FINDINGS With the foregoing considerations in mind, a summary of the Forbes and . Waite findings can be presented. The characteristics of the hypothetical TABLE 6 COMPARATIVE COST OF SERVICE COPY OF MICROFILM OF 40 MILLION PAGES OF BOUND PERIODICALS USING ALTERNATIVE CAMERA SET-UPS AND WITH VARYING NUMBER OF SUBSCRffiERS Rotary plus All planetary cameras planetary cameras Master negative Direct cost, from Table 2 $332,372 $263,183 Overhead (50%) 166,186 131,592 Service copy Direct cost, from Table 5 Diazo• 24,920 24,920 Kodachrome 7,553 7,553 Overhead (20%) 6,495 6,495 Total, master and one service copy $537,526 $433,743 Cost of each additional service copy 35,968 35,968 Subscription to one service copyt 537,526 433,743 1 subscriber 5 subscribers 136,279 115,522 10 subscribers 86,123 75,745 20 subscribers 61,196 56,006 30 su bscri bers:t: 52,886 49,427 * The cost of each diazo copy beyond the first is $22,420. t If it should be decided to dispense with color prints in the service copies (although they would be retained in the master copy) a reduction of about $10,000 could be effC!.::ted in the subscription price at all number of subscnptions, accounted for by the cost of a color print ($7,553) plus cost of splicing, offset by the cost of a b&w print plus the proportionate cost of the b&w negative. *It is noteworthy that as the number of subscribers mcreases the difference in cost between the two camera set-ups rapidly diminishes. JANUARY 1963 11 TABLE 7 COST OF PROVISION OF STORAGE SPACE FOR 40 MILLION PAGES OF BOUND PERIODICALS IN ORIGINAL FORM COMPARED WITH COSTS (FROM TABLE 6) OF SUBSTITUTING MICROFILM, SHARED AMONG 20 SUBSCRIBERS Originals Microfilm All planetary cameras B&w with color All b&w Rotary plus planetary cameras B&w with color . . . . All b&w collection which was the subject of their study is shown in Table I. For the reduc- tion of this collection to microfilm, their report provides detailed specifications of the equipment, supplies, manpower, and procedures involved in the several opera- tions concerned with the originals (in- cluding inventory check, transport, pre- inspection, shearing of backs, and micro-· filming), with the handling of the master film (including processing, splicing, post- inspection, boxing, labeling, and stor- ing), and with the production of the serv- ice copies. Only the resultant cost esti- mates are of concern here. Table 2 shows the comparative costs of producing the master negative by vari- ous methods. Tables 3 and 4 show the details of the estimates of the two principal methods, i.e., all planetary cameras and a combi- nation of rotary and planetary cameras. Table 5 shows comparative direct costs of producing service prints. To the direct costs of making the nega- tive and service prints shown in Tables 2-5 must be added costs of rental of space, administration, etc. Forbes and Waite calculate that approximately 4,500 to 5,000 square feet of space will be need- ed for the operation which will require a full-time supervisor with thirteen to six- teen production people and considerable record keeping. They conclude that over- head charges should be estimated at 50 per cent of the direct charges for the master film and at 20 per cent of those for the service prints. Construction of Cost of film storage space Total $63,500 $63,500 $61,196 2,620 63,816 51,196 2,620 53,816 56,006 2,620 58,626 46,006 2,620 48,626 Table 6 shows the final cost of a diazo- Kodachrome service print when (1) the negative has been made by one of the two principal methods identified in Ta- ble 2 and further described in Tables 3 and 4; (2) when the overhead cost has been added; and (3) when the number of subscribers is 1, 5, 10, 20 or 30. CosT OF MICROFILMING VS. CosT OF STORAGE OF ORIGINALS An estimate of the cost of reducing to microfilm a collection of 100,000 bound volumes of periodicals, incorporating for- ty million pages, has now been reached. How does this cost (plus the cost of pro- viding storage space for the resultant films) compare with the cost of providing storage space for the originals? I. A typical case. To answer this ques- tion a typical case will be taken. It will be assumed: a) That the average height of the vol- umes is less than 12 in., permitting them to be shelved on seven shelves per section in a 7 ft. 6 in. high stack, on 10 in. deep shelves. b) That the volumes are shelved "sol- id," i.e., with no vacant space on the shelves. c) That the average page-density of the collection is 5,000 pages per linear foot. d) That the microfilms would be shelved "solid," in boxes 3% x 3% x I in., in two rows on 8 in. deep shelves, eighteen shelves per sec- tion, in a 7 ft. 6 in. high stack. 12 COLLEGE AND RESEARCH LIBRARIES e) That the shelved area constitutes 30 per cent of the book stack area for the 10 in. shelves and 26 per cent for the 8 in. shelves (these proportions hold when space for aisles, stairways, etc. remains con- stant). f) That the cost of construction is $20 per sq.ft., including cost of shelv- ing. Under the circumstances dictated by these assumptions, forty million pages would require 2,667 36 in. shelves, i.e., 381 7-shelf sections covering 952.5 sq.ft. and requiring 3,175 sq.ft. of bookstack space, the construction cost of which would be $63,500. The 21,187 rolls of microfilm, at 72 rolls per 36 in. shelf, would require 294.3 shelves in 16.4 IS- shelf sections covering 34 sq.ft. and re- quiring 131 sq.ft. of bookstack, the con- struction cost of which would be $2,620. For the conditions of the typical case, it appears, in consequence, that when there are twenty subscribers the cost of a print to each by the most expensive method of Table 6, plus the cost of the storage space for it ($61,196 plus $2,620, totaling $63,816) is almost exactly equal to the cost of providing storage space for the originals ($63,500). This may be seen in Table 7, where it also appears that if black and white were acceptable in the print to the exclusion of color (though color would be retained in the master) the difference in favor of film would ad~ vance to slightly less than $10,000; while if, in addition, rotary cameras could be employed, the difference in favor of film would raise to approximately $15,000. 2. Variations from the typical case. It is obvious, however, that al~ost every one of the assumptions adopted for the typ- ical case is subject to wide variation. The principal of these are: Page density. Pritsker and Sadler based their estimates upon a count of 4,600 pages per linear foot, which they found to obtain in the storage library of the School of Engineering at Columbia Uni- JANUARY 1963 versity. From the unpublished masters' thesis from which their article was con- densed it appears that this figure was composed of a count of 4,142 pages per foot for monographs and 5,152 for peri- odicals.5 The present authors have found the following wide range in various pa- pers: Mimeographed documents (printed on one side of the leaf without hard Pages per foot covers) 2,400 A sampling of 21 bound volumes of professional and general journals (in- cluding 7 in chemistry, others in physical and social sciences, law, etc.) in the library of Georgetown Uni- versity . . . . . 5,240 Collier's Encyclopedia, 1962 . . . . 6,560 English-finish book paper (U. S. Gov- ernment Printing Office specifica- tions; without hard covers) . . 9,600 Machine-finish book paper (U. S. Gov- ernment Printing Office specifica- tions; without hard covers) . . . 11,010 Who's Who in America, vols. 27-32 . 12,362 Anthony Trollope, Barsetshire Chron- icles (London: Nelson, 19'14; New Century Library, Royal India Paper edition) . . . . . . . . . 18,336 It is apparent that page density can vary widely and that the actual density in any particular case will materially affect the ability of microfilm to compete with the originals in cost of storage. Thus, the one roll of film that could re- place 10.8 inches of mimeographed ma- terial would replace only 1. 4 inches of the Royal India Paper edition of the Barsetshire Chronicles. Proportion of shelved area to total bookstack space. This, too, can vary with- in wide limits. In many bookstack instal- lations the proportion is as low as 20 per cent. In the typical case, above, the as- sumed ratios of 30 per cent for 10 in. shelves and 26 per cent for 8 in. shelves contemplated 34 in. aisles between ranges of shelves and a 3 ft. 6 in. main aisle. (In a typical Library of Congress Annex bookstack, with 10 in. shelves separated by one inch on a 21 in. base, the propor- 5 Pritsker and Sadler, "An Evaluation of Microfilm as a Method of Book Storage," Department of In- dustri a l Engineering, Columbia University, 1956. Un- publi shed master's thesis, p. 12-13. 13 TABLE 8 COST OF PROVIDING STORAGE SPACE FOR 40 MILLION ORIGINAL PAGES OF PERIODICALS-EFFECT OF VARIATIONS IN PAGE DENSITY, PROPORTION oF SHELVED TO ToTAL BooKsTACK AREA, AND CoNSTRUCTION CosT PAGE DENSITY OF PROPORTION OF COST OF CONSTRUCTION AT VARIOUS RATES PER SQ. FT., INCLUDING SHELVING ORIGINALS IN PAGES SHELVED AREA TO PER LINEAR FOOT TOTAL BOOKSTACK AREA $15 $20 $25 4,000 20% $89,269 $119,025 $148,781 30% 59,513 79,350 99,187 40% 44,634 59,513 74,391 5,000"' . 20% 71,438 95,250 119,063 30% 47,625 63,500 79,375 40% 35,719 47,625 59,531 6,000 20% 59,513 79,350 99,188 30% 39,675 52,900 66,125 40% 29,756 39,675 49,594 7,000 20% 51,019 68,025 85,031 30% 34,013 45,350 56,688 40% 25,509 34,013 42,516 8,000 20% 50,006 66,675 83,344 30% 33,338 44,450 55,563 40% 25,003 33,338 41,672 * The italicized figures are those of the typical case, supra. tion of shelved to total area is 28 per cent.) If in the same bookstack the aisles between ranges were reduced to 20 inch- es the proportion would rise 40 per cent, and even higher ratios can be achieved by various methods of compact storage. Construction cost. This can vary, in one- to multiple-story buildings of insti- tutional or warehouse character, from $10 to $30 per sq. ft. Table 8 shows the effect of a number of these variables upon the cost of pro- viding storage space for forty million pages of journals. It appears from Table 8 that the cost of constructing storage space for forty million pages of bound periodicals, shelved "solid," can vary from a low of $25,003 (when the page density is 8,000 per foot, the shelves occupy 40 per cent of the bookstack area, and the cost of construction is $15 per sq. ft.) to a high of $148,781 (when the page density is 4,000 per foot, the shelves occupy only 20 per cent of the bookstack area, and the cost of construction is $25 per sq. ft.). Meanwhile Table 6 indicates a cost of $136,279, at the five-subscriber level, for microfilm. The wide discrepancy between these figures shows, if any demonstration were necessary, the need for precision in esti- mating before taking action in this field. However, it also provides wide latitude in response to the question under con- sideration. It appears that while there are situations in which it is more ex- pensive to microfilm than to retain the originals, the reverse is true if suitable conditions exist in terms of cost of stor- age of the originals and the number of subscribers. 3. An actual example. In an attempt to apply the findings of this report to an actual situation, the collection of bound volumes of medical journals prior to 1946, housed on level C of the new N a- tiona! Library of Medicine was exam- ined. The characteristics of the situation were found to be as follows: 14 COLLEGE AND RESEARCH LIBRARIES Area employed for book storage (including shelving, aisles, stairways, elevators, etc.) . . . . Portion of storage area occu- pied by shelving . Portion of shelved to totar storage area . Height of stacks Shelf length . Total linear feet of shelving . Linear feet of shelving now occupied . Average page density (sam- pled) Cost of construction per sq.ft. (entire building) . 15,300 sq.ft. 4,160 sq.ft. 27 per cent 7ft. 6 in. 35.5 in. 34,256 17,210 4,866 pages per ft. $28.906 The collection now housed in the area (approximately 126,000 volumes) is es- timated to contain 83.74 million pages. At the rates cited in Table 6 the cost of a service microfilm copy to each of ten subscribers (including color film when the original was in color, and a propor- tionate share of the costs of the negative) would be $180,342 per subscriber for all- planetary work, and $158,610 if rotary cameras could be employed. If all shelves in the area were filled to capacity (i.e., "shelved solid") at present page density, the collection would amount to 166.7 million pages. Under the conditions cited the cost to a sub- scriber would be $358,900 (all-planetary) or $315,700 (rotary cum planetary). Meanwhile the construction cost of the area (neglecting the stack equipment), if computed at the average for the whole building, may be estimated to have been $442,170. Even if a differential of nearly $5 per sq.ft. is made in favor of stack areas, giving a cost of $24 per sq. ft., the construction cost would have to be esti- mated at $367,200. CoNCLUSION The findings of Pritsker and Sadler can now be extended and brought down to date. They found that microfilm can be successfully applied to reduction of 6 This is an arbitrary figure, and incl':ldes all ~osts in any way referable to NLM c;onstructlon. It mclud:es costs for furniture and ~qmpment, m.urals, spectal sewer connections, landscapmg, .road-net tmprove!llen~s, moving, and similar costs whtch are not ordmanly considered on a per-square-foot ba sts. O:r:t . t.be other hand, it does not include cost of land acqmsttlon. JANUARY 1963 storage costs only at the sacrifice of a less- than-perfect image, no inspection of the film, use of the negative as a service copy, and destruction of the original text. The loss of co,lor information also was im- plicit in their discussion. It now appears that such application can be effected without any of these sacrifices (except that of destruction of the text) provided that a suitable number of participants can be found. The number of partici- pants required (five or more) will de- pend upon circumstances, principal of which are the page density of the original material, the cost of providing storage space for it, and the extent to which it contains material (in color, of unusual size, etc.) requiring special treatment in the microfilming. While it is true that in the right com- bination of circumstances (number of subscribers, page density of original ma- terial, etc.) the resultant savings in stor- age cost from reducing a collection to microfilm may be substantial, yet it is obvious that the difficulty of organizing a project involving multiple subscribers, together with considerations omitted from the present discussion, such as pro- vision of viewing equipment, the ques- tion of copyright in the multiplication of copies, etc., will prove under present conditions strong deterrents to an under- taking in the interest of space saving alone. However the situation might change radically if, for example, a high-ratio-reduction microfilming proc- ess should become practical. This study has been held strictly to the question of storage costs, in order to elicit the facts of the relationship of mi- crofilming to them. However, storage costs are possibly less important than other aspects of library work which mi- crofilm can affect, such as acquisition (or distribution), preservation, binding, and service. It is hoped that this report may, in a sense, dispose of the storage aspect so that the others can be given their rightful attention. • • 15