from the ,google ,print project47 ,,united ,,states ,,patent ,,office ,,the ,,classification ,,of ,,patents ,illustration3 ,department of the ,interior ,,washington ,,government ,,printing ,,office #aiae ,,prefatory ,,note4 ,parts ,a and ,b of the following pages are designed to acquaint all persons using the ,patent ,office classification with the principles upon which the reclassification is proceeding4 ,part ,c consists of a few tentative rules advanced with the notion of fixing classification practice within the office in certain doubtful cases4 ,part ,d is intended to inform examiners reclassifying within examining divisions respecting the initial procedure in reforming a class4 ,,contents4 ,page4 ,a4 ,introduction4 #a ,past classifications of the ,u4 ,s4 ,patent ,office4 #a ,beginning of revision4 #b ,precedents and authorities4 #c ,definition of scientific classification4 #d ,b4 ,principles of the new classification of the ,patent ,office4 #d ,elements of a ,patent ,office classification4 #d ,basis of classification4 #e ,art as a basis4 #e ,function or effect as a basis4 #g ,structure as a basis4 #h ,division and arrangement4 #i ,infinitude of possible combinations4 #aj ,division and arrangement in the natural sciences4 #aj ,difficulty of entitling a subclass corresponding to every combination4 #aa ,expedients to reduce the number of subdivisions4 #ab ,superiority and inferiority4 #ae ,definite positional relationship of subdivisions4 #af ,indented schedules4 #ag ,bifurcate division4 #ai ,utility of arrangement according to resemblances4 #ai ,definition4 #bj ,cross-references and search-notes4 #ba ,diagnosis to determine classification4 #bb ,claimed or unclaimed disclosure4 #bb ,diagnosis of pending applications4 #bc ,difficulties due to varying ideas of claims4 #be ,c4 ,rules of classification4 #bf ,basis of classification4 #bf #a4 ,art as the basis4 #bf #b4 ,operative or manipulative arts4 #bf #c4 ,structures4 #bf #d4 ,composition of matter and formed stock4 #bf ,division and arrangement4 #bg #e4 ,exhaustive division2 miscellaneous subclass4 #bg #f4 ,subclasses not to overlap4 #bg #g4 ,subclasses of any group to be formed on one basis4 #bg #h4 ,apparent exception to rules #f and #g4 #bg #i4 ,relative position of subclasses4 #bg #aj4 ,indention of subclasses4 #bi #aa4 ,different kinds of titles for subclasses4 #bi #ab4 ,arrangement to limit search and cross references4 #cj ,definition4 #cj #ac4 ,tentative definition4 #cj #ad4 ,how to define4 #cj #ae4 ,explanatory notes may sometimes displace definition4 #ca ,cross-references and search-notes4 #ca #af4 ,impossibility of cross-referencing all disclosures4 #ca #ag4 ,occasion and direction of cross-referencing4 #ca #ah4 ,occasion and scope of search-notes4 #cb ,diagnosis to determine classification4 #cb #ai4 ,patents diagnosed by claimed disclosure4 #cb #bj4 ,patents diagnosed by most intensive claim4 #cc #ba4 ,exception to rule #ai1 claim1 for a part of a disclosed combination4 #cc #bb4 ,exception to rule #ai1 claims for a part of a disclosed combination4 #cc #bc4 ,exception to rule #ai1 generic combination old as matter of common knowledge4 #cd #bd4 ,exception to rule #ai1 article of manufacture defined only by material4 #cd #be4 ,exception to rule #ai1 utilizing a composition4 #cd #bf4 ,exception to rule #ai1 utilizing a machine4 #cd #bg4 ,patents having claims for several different inventions4 #ce #bh4 ,general rule of superiority between statutory kinds of invention4 #ce #bi4 ,exception to rule #bh4 #ce #cj4 ,process and apparatus4 #cf #ca4 ,article of manufacture and instrument for making a part of it or performing any minor act relative thereto4 #cf #cb4 ,process and product where search for the process would have to be made among machines4 #cf #cc4 ,process and product where search for the process would have to be made among products4 #cf #cd4 ,process of making a composition and the composition where the process is peculiarly adapted to make the composition4 #cg #ce4 ,article of manufacture or composition and process for making one of the parts of the article or ingredients of the composition4 #cg ,d4 ,procedure in reclassifying within examining divisions4 #cg #a4 ,general attitude4 #cg ,procedure involving only cursory scrutiny of familiar patents-- #b4 ,consider wholes in forming tentative subdivisions of subclasses4 #ch #c4 ,write tentative definitions of subdivisions4 #ch #d4 ,consider the significance of analogies found to traverse parts of two or more existing subclasses4 #ch #e4 ,arrange groups on parallel or accordant lines where practicable4 #ch #f4 ,watch for subcombinations deserving separate recognition4 #ch #g4 ,consider whether the groups collectively will constitute a proper class and their best correlation4 #ch ,procedure involving rigorous analysis-- #h4 ,diagnose each patent for original classification4 #ci #i4 ,group and consider the disposition of patents deemed foreign to the class4 #ci #aj-ae4 ,consider and indicate cross-referencing within and to and from the class4 #ci1 #dj ,note4 #dj ,,the ,,classification ,,of ,,patents 7,a7 ,,introduction4 ,classification lies at the foundation of the mental processes4 ,without the power of perceiving1 recognizing resemblances1 distinguishing differences in things1 phenomena and notions1 grouping them mentally according to those resemblances and differences1 judgment is impossible1 nor could reason be exercised in proceeding from the known to the unknown4 99 99 99 99 99 ,the facilitation and abbreviation of mental labor is at the bottom of all mental progress4 ,the reasoning faculties of ,newton were not different in qualitative character from those of a ploughman2 the difference lay in the extent to which they were exerted and the number of facts which could be treated4 ,every thinking being generalizes more or less1 but it is the depth and extent of his generalizations which distinguish the philosopher4 ,now it is the exertion of the classifying and generalizing powers which thus enables the intellect of man to cope in some degree with the infinite number and variety of natural phenomena and objects4 7,jevons1 ,principles of ,science47 ,,past ,,classifications ,,of ,,united ,,states ,,patent ,,office4 ,as under the patent laws the people of the ,united ,states assume all the risks in granting a patent for any means of the useful arts1 a classification that will facilitate a judgment respecting the patentability of any means presented to the ,patent ,office is of peculiar moment4 ,the enormous extent1 diversity1 and refinement of the useful arts preclude the formation of a judgment on novelty within a reasonable time1 unless the necessary comparisons with known processes and instruments have been previously made along the lines that searches must follow and the results of such comparisons made available in a classification4 ,the vast majority of available disclosures of the arts occur in patents4 ,hence the ,patent ,office classification must be adjusted in the main to the analysis1 diagnosis1 and orderly arrangement of the disclosures of patents4 ,for more than #hj years ,united ,states patents have been classified4 ,the first published classification1 promulgated in #ahcj1 comprised #f1agj patents1 divided into #af classes4 ,the change from a registration to an examination system in #ahcf instigated a new classification in #bb classes1 including #i1hjj patents4 ,the next came in #ahfh with #cf classes1 including about #ge1jjj patents4 ,on ,march #a1 #ahgb1 a revised classification was adopted1 comprising #ade classes1 including #aca1jjj patents4 ,this classification is said to have been planned by ,dr4 ,edward ,h4 ,knight4 ,the placing of the patents in accordance with the schedule of classes is said to have been done by the several examiners4 ,the class arrangement was purely alphabetical by class titles1 and the number designations followed the alphabetical order4 ,the names of things to be found in the several classes were arranged alphabetically under each class title4 ,no attempt was made to bring the titles of allied materials into juxtaposition or to effect other definite arrangement with reference to subject matter in the printed schedules4 ,a consolidated name index supplemented the list of names by classes4 ,this classification of #ahgb is in part the classification that now exists1 many of the same class numbers and titles being still in use4 ,examiners were apparently permitted to make changes in classification to suit their convenience without notice until #ahgg4 ,in that year a revision of the published schedule was made by a committee1 resulting in the addition of #ac new classes1 and examiners were ordered to transfer patents in accordance with the new titles4 ,the first classification published with distinct subclasses appeared in #ahhj4 ,from that time until #ahih the classification grew by addition and subdivision of classes to suit the ends of individual examiners or in response to supposed exigencies of the work where one division was thought to be overloaded and another underloaded1 and the alphabetical arrangement of subclasses under each class has succeeded the alphabetical list of names4 ,the arbitrary correspondence originally established between the alphabetical order of class titles and the numerical order was destroyed as soon as expansion of the classification began4 ,however suitable to the then-existing material of the useful arts the classification of #ahgb may have been1 it failed as fail all inductive processes wherein the generalizations are not broad and deep4 7,isaac ,newton's intellect could detect the resemblance between the falling fruit and the motions of the planets47 ,the classification of #ahgb was not exhaustive2 it failed to recognize to the fullest extent what ,bishop ,wilkins saw nearly #cjj years ago1 to wit1 that there are arts of arts2 and it failed to provide for future invention of new species in the same art1 and to recognize that new arts could be formed from combinations of the old4 ,,beginning ,,of ,,revision4 ,the ,classification ,division was created in the hope that guiding principles of classification could be developed and applied for the purpose of amending or revising the classification whereby patents could be placed with greater assurance1 and whereby the searcher with these guiding principles in mind might find the nearest references4 ,it was confronted with the problem of revising while at the same time keeping accurate record of all changes1 correcting all indexes of patents1 and using copies in constant demand for search at the same time1 necessitating much clerical work1 and constant interruption--of correcting rather than planning anew2 of mending a machine while constantly increasing duty was required of it4 ,ideas on the subject of revision were called for by the ,commissioner of ,patents1 and all in the ,patent ,office had an opportunity to set forth their notions4 ,the views of one met with approval and in accordance with those views a ,plan of ,classification was prepared and promulgated in #aijj4 ,what other plans may have been submitted is not now generally known4 ,but in substantial accordance with that published plan1 the process of revision has proceeded for more than #ad years until approximately #ej per cent of the patents 7including incomplete work7 have been placed in revised classes4 ,,precedents ,,and ,,authorities4 ,no effective precedents have been found in any prior classifications of the arts4 ,the classifications of the principal foreign patent offices have not been materially different in principle from the ,united ,states ,patent ,office classifications of the past4 ,the divisions found suitable for book classification for library use1 have not been deemed adequate to the exactness and refinement essential to a patent office classification of the useful arts4 ,the systems of class and subclass sign or number designations of the modern library classifications1 with their mnemonic significance1 afford the most important suggestions to be drawn from library classification4 ,none of these systems of designation has been adopted1 7#a7 because of a serious doubt as to the availability of such designations by reason of the length or unwieldiness to which they would attain in the refinements of division necessary in a patent office classification1 and 7#b7 because of the enormous amount of labor necessary to make the change from present practice4 ,the best analogies are in the known 7but changing7 classifications of the natural sciences1 and in them the problems are so different that they can serve only to illustrate general principles4 ,the broad principles of classification are well understood4 ,the authorities are the logicians from the ancient ,aristotle to the modern ,bentham1 ,mill1 and ,jevons4 ,the effort of the ,classification ,division has been to adapt and apply these well-known principles to the enormously diversified useful arts1 particularly as disclosed in patents and applications for patents4 ,,definition ,,of ,,scientific ,,classification4 ,it may be well to insert here an authoritative definition3 ,a scientific classification is a series of divisions so arranged as best to facilitate the complete and separate study of the several groups which are the result of the divisions as well as of the entire subject under investigation4 7,fowler1 ,inductive ,logic47 ,investigation and study of any subject will be facilitated if the facts or materials pertinent to that subject be so marshaled and arranged that those most pertinent to it may appear to the mind in some form of juxtaposition4 ,it is the purpose of the ,patent ,office classification to divide and arrange the body and multitudinous units of the useful arts so that1 having the question of novelty of any defined means to answer1 one may with reasonable assurance approach that portion of the rank of arts in which it will be found if it is not new1 and in propinquity to which will also be found those means that bear the closest resemblances to that sought for1 the resemblances of other units growing less in proportion to their distance therefrom4 ,success in the fundamental aim of facilitating adequate search should evidently at the same time reduce proportionately the danger that interfering applications will be overlooked and also effect a distribution of labor favorable to the acquisition of special skill4 7,b7 ,,principles ,,of ,,the ,,new ,,classification ,,of ,,the ,,patent ,,office4 ,,the ,,elements ,,of ,a ,,patent ,,office ,,classification4 ,a classification will be useful in proportion 7#a7 to the pertinence to the subject under investigation of the facts selected to be grouped together1 or1 in other words1 in proportion to the appropriateness of the basis of classification to the subject in hand2 7#b7 to the convenience1 stability1 and uniformity of the arrangement of the subdivisions whereby the investigator may proceed with reasonable assurance to that portion of the rank of groups within which he will find cognate material2 7#c7 to the accuracy and perspicuity of the definitions of the several divisions and subdivisions2 7#d7 to the completeness and reliability of the cross-referencing and cross-notations2 7#e7 to the uniformity1 feasibility1 and certainty of the rules by which the accessions of patents disclosing one or several inventions may be diagnosed and distributed to the appropriate divisions of the classification in accordance with the basis adopted4 ,corresponding to the foregoing analysis the theory of ,patent ,office classification may be treated in five parts3 7#a7 ,the principles on which the arts shall be divided 7basis of classification72 7#b7 subdivision and mechanical arrangement of groups2 7#c7 definition2 7#d7 cross-referencing and search-notes2 7#e7 the choice of features by which a patent shall be assigned in the classification 7diagnosis74 ,,basis ,,of ,,classification4 ,the first and most vital factor in any system of classification is the basis of division1 that is1 the kind of characteristics common to any number of objects selected to characterize groups1 whereby the individuals of any group will resemble each other for the purpose in view more closely than any individual in any group will resemble any individual in any other group4 ,there is no property of objects which may not be taken1 if we please1 as the foundation for a classification or mental grouping of those objects1 and in our first attempts we are likely to select for that purpose properties which are simple1 easily conceived1 and perceptible in a first view without any previous process of thought--but these classifications are seldom much adapted to the ends of that classification which is the subject of our present remarks4 7,j4 ,s4 ,mill1 ,system of ,logic47 ,it is clear that a number of objects may be classified on several different bases4 ,for example1 a number of books could be divided into groups 7#a7 according to the subject of their contents2 7#b7 according to the language in which the books are written2 7#c7 according to the size of page2 7#d7 according to the binding material2 or 7#e7 according to the color of the binding4 ,each of these may be useful classifications for some purpose4 ,for the student of literature none is of value except the first2 for the connoisseur in bindings1 only the last three4 ,a classification of animals including classes of land animals and water animals would hardly suit a student of zoology1 as it would associate with the shad and perch such differently organized creatures as the porpoise1 whale1 and seal4 ,yet such a classification might prove very suitable for a student of fisheries4 ,art as a basis4#a--,so in seeking a basis for a patent office classification the purposes of the classification should be the guide4 ,allegations of ulterior uses#b 7such as may be made merely because the inventor thought of applying his invention to those uses only1 or in an effort to get the application examined in a certain division7 and other superficial bases should be avoided4 ,that basis will best suit the purpose which effects such an arrangement as will exhibit in suitable groups the state of the prior art1 by which is here meant not necessarily all the instruments of a trade or industry1 or all the articles sold by a shopkeeper1 as a stationer1 but those means that achieve similar results by the application of similar natural laws#c to similar substances4 ,as all inventions are made with the ultimate object of satisfying some human desire1 the utility of an invention appears to be a natural basis of classification4 ,it is apparent1 however1 that most inventions may contribute to numerous utilities besides the ultimate one4 ,many processes and instruments intervene between the seed planter and the wheaten rolls upon the breakfast table4 ,the plow may be viewed as an agricultural instrument or as an instrument of civil engineering1 according as it is used for preparing the field for planting or rounding a road4 ,a radiating coil of pipe may be thought of as a condenser of steam or of alcoholic vapors1 according as it is applied to one material or another2 as a cooler or a heater1 according to the temperature of a fluid circulated through it4 ,a hammer may drive nails1 forge iron1 crack stone or nuts4 ,underlying all of these ulterior utilities1 there is a fundamental one to which the normal mind will reach in its natural processes and there rest4 ,the plow loosens or turns over the surface of earth2 the coil effects an exchange of heat between its interior and exterior2 the hammer strikes a blow4 ,a classification of plows in agriculture1 road building1 or excavating1 according to stated ultimate use2 of a radiator coil as a steam condenser1 still1 jacket-water cooler1 refrigerator1 or house heater2 of the hammer as a forging tool1 a nail driver1 or a nut cracker1 appears to separate things that are essentially alike4 ,but classifying a plow on its necessary function of plowing1 a radiator on its necessary function of exchanging heat1 a hammer on its necessary function of striking a blow1 evidently results in getting very similar things together4 ,assuming for the moment that utility is a reasonable basis of division of the useful arts1 it is deemed more logical to adopt as a basis some utility that must be effected by the means under consideration when put to its normal use rather than some utility that may be effected under some conditions4 ,two of the five predictables of ancient logic are property#d and accident4#e ,the capacity of the hammer to strike a blow1 the capacity of the radiator coil to exchange heat1 are in the nature of properties4 ,the capacity of the hammer to crack nuts1 of the coil to condense steam1 are in the nature of accidents--something that follows from the impact and the heat exchange because of the particular accidental conditions of operation4 ,to select an accident as a basis of classification is contrary to the laws of thought4 ,it may be said then that the ,patent ,office classification is based upon art in the strict sense in which the word may be said to be used in section #dhhf1 ,revised ,statutes1 but not necessarily in the looser sense of industries and trades4 ,a proper maintenance of the distinction between the word arts of the statute and the phrase industrial arts used in the sense of industries and trades is essential to an effective classification for the purposes of a patent office search4 ,similar instruments have been patented in three different classes1 because of the statements that one was designed for cooling water1 another for heating water1 another for sterilizing milk2 in four different classes1 because of the statements that one apparatus was to separate solids from the gases discharged from a metallurgical furnace1 another to separate carbon from the combustion gases of a steam-boiler furnace1 another to remove dust and tar from combustible gas1 and another to saturate water with carbon dioxid4 ,owing to the continuance of a classification based largely on remote use1 many applications come into the office setting forth inventions of very general application which nevertheless have to be classified more or less arbitrarily in one of several arts in which they may be used but to which they are not limited4 ,function or effect as a basis4#f--,means of the useful arts are related in different degrees4 ,resemblances selected as bonds for a number of inventions may be more or less close4 ,it is axiomatic that close resemblances should be preferred over looser ones for classification purposes4 ,processes and instruments for performing general operations1 such as moving1 cutting1 molding1 heating1 treating liquids with gases1 assembling1 etc41 are more closely bonded than those for effecting the diverse separate successive operations directed toward complex special results1 such as making shoes1 buttons1 nails1 etc4 ,means of the former sort perform an essentially unitary act--the application of a single force1 the taking advantage of a single property of matter4 ,those of the latter sort require the application of several different acts employing frequently a plurality of forces or taking advantage of several properties of matter4 ,in the former case1 classification can be based on what has been called function1 in the latter it cannot be based on function but can be based on what has been called effect 7or product74 ,function is closely related to cause4 ,it is an axiom of logic that cause is preferable to effect as a basis of those classifications designed for scientific research4 ,hence the functional basis is preferred in all cases in which it can be applied4 ,a condenser for the fumes of zinc is much more like a condenser for the fumes of acid or the vapor of water than it is like the art of recovering zinc from its ores1 and it employs only one principle1 to wit1 heat interchange4 ,a water-jacket for cooling the walls of a gas-producer or glass-furnace is much more like a water-jacket for cooling the walls of a limekiln or steam-boiler furnace than it is like the art of gas-making or manufacture of glass articles4 ,in accordance with what are thought to be the correct principles1 therefore1 the zinc-condenser ought not to be classified as a part of the art of metallurgy1 nor the water-jacket as a part of the art of gas-making1 merely because these instruments have a use in these arts1 but should be included1 respectively1 in classes based upon the more fundamental utilities effected by them4 ,although it is evident that molding a button is more like molding a door-knob than it is like making buttons by the combined operations of sawing1 grinding1 turning1 and drilling1 wherefore the molding of buttons should be classified in a general plastic art rather than in a special button-making art1 yet the making of buttons by a plurality of different kinds of operations can be placed only in a class based upon the product1 to wit1 button-making4 ,since1 therefore1 the combination of many different operations for the production of a specific article can not be classified on the basis of any single function1 it must be classified on the basis of product4 ,thus by selecting essential function as a basis when possible1 and resulting effect when the functional basis is not possible1 one may approximate to the correct classification described by ,herbert ,spencer as follows3 ,a true classification includes in each class those objects that have more characteristics in common with one another than any of them have with objects excluded from the class4#g ,so it is deemed better to classify in accordance with the function or effect it is known a means must perform or accomplish than in accordance with the object with respect to which an act or acts are directed or in accordance with some effect which may or may not result4 ,structure as a basis4--,the phrase structural classification is frequently made use of4 ,the application of the phrase to processes is manifestly absurd4 ,the ,patent ,office never had a structural classification except in a limited sense4 ,how could a machine1 for example1 be classified on structure1 leaving out of consideration its function and the effect of its normal operation8 ,in the refinements of subdivision however1 it becomes frequently desirable to form minor subdivisions on structural differences4 ,and it may also be that instruments will be presented for classification that are of such general utility as to baffle the efforts of the intellect to attain to the fundamental and necessary function1 in which case a structure-defined class may best suit the needs of classification4 ,as between a classification based upon structure and one based upon utility1 the choice has been for the latter1 without prejudice1 however1 to instances that may arise in favor of the former4 ,the subject of structural classification will be dropped with a quotation from the original pamphlet ,plan of ,classification1 etc4 7p4 #e73 ,a purely 'structural' classification is almost impossible on account of the infinite variety of mechanical combinations1 and to attempt it would probably result in utter confusion1 for the classes could not be defined1 and the classification would be a mere digest of mechanical elements having no community of function4 ,,division ,,and ,,arrangement4 ,having divided the aggregate of things to be classified into a large number of groups on a satisfactory basis1 a most useful work will have been accomplished and the purpose of a classification to assemble the things most nearly alike and separate them from other things will have been partially achieved4 ,unless these numerous groups are arranged in some definite understandable relation to each other1 or are placed in definite known positions where they can be found1 the mere formation of the groups1 on however good a basis1 is not a complete classification4 ,furthermore1 unless the position of each group with respect to those other groups that resemble it in whole or in part is made known1 he who wishes to find other related matter must seek aimlessly with no assurance that his quest will end until the whole series shall have been investigated4 ,each classified group is metaphorically a pigeonhole to contain similar material4 ,if the pigeonholes are properly labeled1 one can ultimately locate those that contain the matter he is seeking if he knows the name that has been applied to it4 ,if the pigeonholes are arranged in alphabetical order1 for example1 he may find all related material1 provided he knows the name of every related group of material1 even though very similar things may bear names as far apart as ,a and ,z4 ,but if all things were so placed that1 adjacent and in certain fixed relation to each pigeonhole1 other related matter could be found1 the resemblances lessening in proportion to the separation1 and if the entire area of pigeonholes were divided1 and certain areas assigned to certain kinds of things defined in general terms1 guessing the location of and desultory search for things that may have different names1 but yet be very much alike1 would be lessened and all cognate material be bunched4 ,a second vital factor of a system of classification1 therefore1 is the arrangement of the groups4 ,infinitude of possible combinations4--,there are now over #a1abe1jjj ,united ,states patents1 each presumptively covering a creation of the useful arts that is different from every other4 ,most of these patents also disclose a plurality of elements or acts4 ,each of these patented means is potentially an element of a more complex combination that may be patented4 ,when one considers merely the number of forms of energy1 the number of known substances and known mechanical elements1 and attempts to figure possible combinations and permutations1 it becomes apparent that the size of the numbers resulting is incomprehensible4 ,consider the possibilities of combination also of the enormously varied disclosures of patents4 ,calculations of the possible combinations and permutations of a small number of objects are familiar4 ,different combinations of the letters of the alphabet are sufficient to record the sum of human knowledge in many languages4 ,with substantially two octaves of the diatonic scale the world's melodies have been sounded1 nor do any doubt that our successors will thrill to airs that we have never heard4 ,thirty metals may be combined into #dce binary alloys1 #d1jfj ternary alloys1 #bg1dje quaternary alloys 7,jevons74 ,this does not take into consideration differences in proportion that figure so largely in results in the arts of substance-making4 ,the total number of possible alloys of the known metals is incomprehensible4 ,a moment's thought respecting the numbers of the means of the useful arts will alleviate any fears that the possibilities of invention are near the limit and will give food for further thought to all concerned with this attempt to classify the useful arts to the point of refinement necessary to enable this office to pass judgment with reasonable speed and accuracy upon the approximately #ge1jjj applications filed each year4 ,division and arrangement in the natural sciences4--,some of the natural sciences are said to be in what is known as the classificatory stage of development4 ,in some sciences the subject of classification has been predominant and these furnish excellent examples of scientific classification4 ,the much-admired classifications of zoology1 botany1 and mineralogy are among the best available models of logical division1#h systematic and analytical arrangement4 ,the most casual consideration of these classifications1 however1 renders apparent the relative simplicity of the task of classifying natural objects differentiated by fixed natural laws as compared with the task of classifying the products of the creative and imaginative faculties as applied to the useful arts4 ,the chimera and other animal monsters occur only as figments of the mind4 ,zoological classification does not have to classify combinations of birds1 fishes1 reptiles1 and mammals1 nor does it deal in the way of classification with the parts of animals1 nor is the question of absolute numbers of instances a matter of moment to such a classification1 all of the members of a species being alike for classification purposes4 ,but any instrument of the useful arts may be combined with some other1 any part with some other part4 ,organizations may be parts of some other organizations1 or even mutually parts of each other1 as1 for example1 a pump may be a part of a lubricator1 or a lubricator may be a part of a pump4 ,some parts are peculiar to one instrument1 some are common to many4 ,every member of a species differs from every other member4 ,added to this1 the intellectual differences between the persons who present the applications for patent1 the differences in their generalizing powers1 the relatively broad and narrow views of two or more persons presenting the same invention 7variations not indulged in by nature7 complicate the problem of classifying the useful arts4 ,difficulty of entitling a subclass corresponding to every combination4--,in any main class or group of the useful arts there are always a number of characteristics that it may be desirable to take note of in subdivision titles4 ,a moment's thought shows the impossibility of taking care of any large number of combined characteristics so as to provide exactly for each combination1 for the reason that the limitations of space and of the perceptive faculties forbid4 ,for a simple illustration1 the imaginary classification of books for use by a bookseller may be recurred to4 ,the dealer1 it may be assumed1 has books on 7#a7 four different subjects1 history1 science1 art1 and fiction1 7#b7 each printed in four languages1 ,english1 ,german1 ,french1 ,spanish1 7#c7 in four different sizes of page1 folio1 quarto1 octavo1 duodecimo1 7#d7 bound in four materials1 leather1 rawhide1 cloth1 paper4 ,here are four main characteristics1 each in four varieties4 ,a customer is likely to ask for ,ivanhoe in ,english1 octavo1 bound in leather4 ,now if the bookseller had sought to arrange the books into one class according to subject matter1 into another according to language1 another according to size1 another according to binding1 he would have fallen into confusion1 because his classes would be formed on different principles or bases and overlap4 ,some histories will be in ,french1 some will have octavo pages1 and some cloth bindings4 ,but if he divides first on the basis of subject matter1 then each subject matter into language1 each language book into sizes1 each size into material of binding1 he can immediately place his hand on a class wherein the book will be if he has it2 but this classification1 based on four different characteristics and four varieties of each1 has necessitated the formation of #bef classes or divisions1 and if five characteristics were provided for1 #a1jbd divisions would be required4 ,adapting the illustration of the books to a patent office classification3 ,if it were possible to view these characteristics as patentable in combinations of all or in any combinations less than all1 and also as separate characteristics1 #af divisions additional to the #bef for each independent characteristic would have to be provided1 as well as other divisions for combinations of less than the whole1 in order to make the classification absolutely indicative of every feature1 and the number of divisions would be enormous4 ,in such a classification1 after the proper division had been located1 the search would be nothing1 the difficulty would be to find the appropriate class4 ,expedients to reduce the number of subdivisions4--,fortunately most people carry on their mental processes in accordance with certain uniformities4 ,under this uniformity of thought no patentable relationship may be alleged between a quarto volume and the subject of history or between a leather binding and the ,german language2 wherefore #d classes of coordinate value1 based on the #d characteristics1 each divided into #d subclasses1 #af divisions in all1 may serve the purpose of a ,patent ,office search4 ,but if1 as sometimes happens1 a patentable relationship had been assumed and admitted between a leather binding and any of the languages1 or any of the subjects1 or between any two or more of those different characteristics1 provision could be made for such combinations by the following expedients3 7#a7 ,arrange the characteristics1 in the order of relative significance or importance for the purpose in view1 in four groups1 giving each group the characteristic title4 ,under each title arrange the varieties in a similar relation as follows in either 7#a7 or 7#b73 7#a7 7#b7 ,cl4 ,x4--,,books4 ,cl4 ,x4--,,books4 #j4 ,miscellaneous4 #a4 ,subject-matter-- #j4e ,subject-matter-- #b4 ,history4 #a4 ,history4 #c4 ,science4 #b4 ,science4 #d4 ,art4 #c4 ,art4 #e4 ,fiction4 #d4 ,fiction-- #f4 ,language-- #d4e ,language-- #g4 ,english4 #e4 ,english4 #h4 ,german4 #f4 ,german4 #i4 ,french4 #g4 ,french4 #aj4 ,spanish4 #h4 ,spanish4 #aa4 ,size-- #h4e ,size-- #ab4 ,folio4 #i4 ,folio4 #ac4 ,quarto4 #aj4 ,quarto4 #ad4 ,octavo4 #aa4 ,octavo4 #ae4 ,duodecimo4 #ab4 ,duodecimo4 #af4 ,binding-- #ab4e ,binding material-- #ag4 ,leather4 #ac4 ,leather4 #ah4 ,rawhide4 #ad4 ,rawhide4 #ai4 ,cloth4 #ae4 ,cloth4 #bj4 ,paper4 #af4 ,paper4 ,subject-matter1 assumed to be the most important characteristic1 is placed first4 ,any exhibit of mere material for binding1 mere size1 mere language1 or mere subject-matter1 would fall into the correspondingly entitled group4 ,if1 however1 a book on history in ,german or a history in red leather1 etc41 were to be classified1 it would be placed in subclass ,history in the subject-matter group1 and a ,french book in green cloth would be placed in subclass ,french in the language group4 ,that is1 combinations of any characteristic with any one or more other characteristics may be placed in the group for that characteristic deemed the most significant and which is highest in the schedule4 ,again1 by assigning a number to each generic title1 each such title becomes thereby the miscellaneous group for varieties other than those indented under it1 as well as for all varieties associating any characteristic with one or more of those standing lower down4 ,thus1 a book of poems would belong in subclass ,subject-matter and a #afmo volume bound with purple celluloid covers would belong in subclass ,size4 ,so1 by giving meaning to relative position1 exhaustive arrangement is sought to be provided in a reasonable number of groups4 ,to provide for other features that may be presented in future1 an additional miscellaneous group may be added at the top 7#a71 or the class title 7#b7 might be deemed to represent the unclassified residue and a depository for future matter not specifically provided for4 7#b7 ,if the number of instances of association of subject-matter and binding materials1 language and size1 etc41 are numerous1 additional groups might be placed above the groups having the names of the characteristics1 the fact of the existence of these groups indicating that the characteristic groups are for single characteristics only and do not include books having several different ones4 ,in such case the schedule might be headed by a miscellaneous group1 having either the title ,miscellaneous or the title of the class1 to receive associated characteristics not provided for by specific titles1 immediately followed by subclasses for the particular associations found to be most numerous1 as follows3 ,,books4 ,miscellaneous4 ,subject-matter and language4 ,subject-matter and binding material4 ,subject-matter4 ,language4 ,size4 ,binding material4 ,to illustrate further1 selecting for the purpose a mass of objects presenting problems more nearly like those presented to the office in questions of patentability1 let it be assumed that one is to classify the objects in a heap of metal scrap4 ,on looking over the material of the heap it is noticed that there are a large number of metal balls2 some have holes through them1 some are hollow1 some are smooth on the outside1 and some are hollow1 smooth1 and perforated1 but they are all nevertheless balls1 and accordingly all balls can be separated out and placed in a heap by themselves4 ,next1 the presence of bars in the general mass is observed1 some long1 some short1 some straight1 some twisted1 some of round stock1 some of square stock1 etc4 ,these may be gathered together and placed in a separate pile at the left of the balls4 ,it is further observed that there are many differently shaped annular bodies in the heap resembling generally the single links of a chain1 some circular1 some elliptical1 some twisted1 some made of round stock1 some of square stock1 etc4 ,they are all nevertheless annular bodies2 these may be placed in a separate pile at the left of the bars4 ,now1 in the remnant of the original heap1 a sufficient number of similar single elements does not remain from which to make a smaller pile of elements4 ,different combinations of links1 balls1 and bars are1 however1 observed in the remaining heap4 ,some are combinations of links1 some combinations of a ball and link1 some of a bar and link1 and some of a bar1 link1 and ball4 ,these different combinations may be separated out in the order named and placed in separate piles4 ,after all these things have been removed1 there is left in the original heap a number of odds and ends or miscellaneous metal objects4 ,these several groups may now be arranged in the inverse order in which 7in the particular illustration adopted7 they have been removed1 thus3 #a4 ,miscellaneous 7remnants of the original heap of scrap74 #b4 ,combined bar1 link1 and ball4 #c4 ,combined bar and link4 #d4 ,combined bar and ball4 #e4 ,combined link and ball4 #f4 ,chains4 #g4 ,links4 #h4 ,bars4 #i4 ,balls4 ,knowing that objects of metal scrap not covered by the specific titles will be found in the miscellaneous group1 and that the more complex specifically-named things are to be found first after the miscellaneous or at the left of the row of piles of materials thus separated and arranged1 and the more simple things and parts farther to the right1 the particular piles to resort to for the things wanted may be definitely determined4 ,the same processes may be applied to each of the piles4 ,thus1 balls1 in the above illustration1 may be divided into-- ,balls-- #aj4 ,hollow perforated4 #aa4 ,hollow grooved4 #ab4 ,hollow4 #ac4 ,perforated4 #ad4 ,grooved4 ,again1 the same processes may be applied to a mass of more diversified junk1 of which the metal scrap may form one pile1 rags another1 old bricks another1 old timber another1 and1 still another1 timber having metal-straps1 bolts1 nails1 etc41 connected with it4 ,superiority and inferiority4--,in the arrangement of subclasses in a class1 those groups that are related to each other as wholes and parts are arranged so that the wholes shall stand before the parts1 and so that subclasses defined by effect or by special use shall stand before those defined by function or general use4 ,for example1 in the scrap illustration above1 assuming the titles to be in a printed arrangement1 chains precedes links1 which may be parts of chains1 and if it had been desired to separate animal-drags1 for instance1 from the scrap1 some animal-drags being particular adaptations of a bar1 links1 and ball1 the group of animal-drags should precede ,bar1 link1 and ball4 ,the words superior and inferior have been used to indicate this relationship4 ,a class or subclass defined to receive a certain combination is superior to one defined to receive an element or a combination that is a part of that certain combination4 ,a class or subclass defined to receive means for making a particular product1 as an electric lamp1 is superior to a class or subclass designed to perform a general function1 as pumping air from a container4 ,and whenever a question of assignment of a patent or application that contains matters of two or more groups bearing that relation is raised1 the superior group is selected to receive it4 ,further1 in those instances in which groups are formed on different bases or different characteristics1 not comparable with each other1 and a patent is presented having matter falling in each group1 that group which is highest in position is preferred in those instances where separate provision for means having both characteristics has not been made4 ,in cases of necessity1 as where a combination is presented for which no class has been definitely provided1 but classes exist into which the several parts would fall if separately claimed1 the same practice that obtains in similar situations with respect to two or more subclasses of a class may be followed with respect to two or more classes and the patent placed in that class which1 in accordance with above-stated principles1 should be deemed the superior4 ,definite positional relationship of subdivisions4--,in the metal scrap example1 above1 division has been effected on the one basis of form or contour4 ,if it had been desired to separate also on material1 for example1 if it were deemed important to locate all brass scrap1 each of the groups based upon form could be divided into one of brass and one not brass1 or the entire heap could be divided into brass and not brass1 and under the heading brass could be indented the various articles made of brass1 and under not brass the various articles not made of brass1 and this would double the number of divisions4 ,if also it were desired to separate the lead articles in the same manner the number of classes would be tripled4 ,but1 as in the book illustration1 it may be impracticable thus to multiply subdivisions1 and the basis form having been selected as of first-rank importance1 all divisions based upon form should be completed and kept together4 ,then1 material1 having been selected as of second-rank importance1 should be carried out with respect to all objects in which form is non-essential4 ,if enough brass balls were found to render it advisable to make a subdivision of them1 they should be assembled into a subclass indented under balls and not into a subclass indented under brass4 ,having selected one basis as primary1 it should never subsequently be made secondary or vice versa4 ,some such restriction on modes of division appears salutary in a system of divisions designed to definitely limit search4 ,the arrangement herein sought to be explained is susceptible of use to limit all searches for a single definitely stated invention to a subclass properly entitled to receive it or those indented under it1 and to those subclasses above1 which may include it as a part of an organization or specialized means4 ,as between coordinate groups divided on the same basis1 there is no question of superiority and inferiority4 ,the terms superior and inferior are useful in questions of relationship between combinations and subcombinations or elements thereof1 and between groups founded on effect or product and those founded on simple function4 ,the mere difference in complexity of mutually exclusive coordinate groups involves no relationship of superiority or inferiority4 ,a subclass to receive a screw-cutting lathe is superior to a subclass to receive a lathe-headstock1 a locomotive class is superior to a class to receive steam-engines1 for the reason that the lathe is a whole of which the headstock is a part1 and the locomotive is an organization of which the engine is an element4 ,but the headstock subclass is not superior necessarily to the tailstock subclass simply because the headstock is commonly more complex than the tailstock4 ,yet arbitrary preference for classification in the headstock subclass may be established by position where an application or a patent contains claims for both4 ,thus in a class that is founded on a well-chosen basis that brings together things bearing close resemblances to each other1 all types that contain the elements essential to produce a complete practically operative means will be found in subclasses that have a position somewhere between the beginning and end of the list of subclasses of the class4 ,those that add features of elaboration of the essential types and those that are highly specialized to some particular purpose within the definition of the class will stand above the essential type subclasses1 while those subclasses for parts and details will stand below those for the essential types4 ,indented schedules4--,in an indented schedule all subclasses in the first column reading from the left are species to the genus represented by the class title4#i ,all subclasses indented under another subclass are species to the genus represented by the subclass under which they are indented4 ,if a title has no number1 it represents merely a subject-matter to be divided1 a genus1--having no representatives except in the species under it4 ,if a subclass having a generic title has a number1 it not only represents a subject-matter to be divided into species but also all other species not falling within the titles indented4 ,although these relative positions might imply that only proximate species are indented one place1 yet mechanical difficulties render it impracticable to so arrange that all species shall be indented under their proximate genera4 ,indention properly carried out has a tendency to prevent in the process of logical division the logical fault of proceeding from a high or broad genus to a low or narrow species4 ,this latter fault may inadvertently separate things that belong together4 ,if1 for example1 it were desired to divide balls in the stated illustration according to material1 an immediate division of balls into aluminum1 zinc1 glass1 ivory1 rubber1 would be less useful than to divide into mineral materials and nonmineral materials as follows3 ,balls-- ,mineral-- ,nonmetallic-- ,glass4 ,metallic-- ,aluminum4 ,zinc4 ,nonmineral-- ,vegetable-- ,rubber4 ,animal-- ,ivory4 ,however1 it is evident that indention carried to its full extant1 useful as it is in keeping analogous things together1 would make the printing of schedules complex and unwieldy4 ,nevertheless1 in the generalizing process necessary in logical division and arrangement1 the divisions of species should always be mentally indented1 as it were1 under their proximate genera4 ,thus1 under a genus unnamed may be arranged several species in juxtaposition1 without actually printing the name of the genus1 so that the schedule above may read3 ,balls-- ,glass4 ,aluminum ,zinc4 ,rubber4 ,ivory4 ,in an arrangement printed in idea-order1 though relegating the genera mineral1 nonmetallic1 metallic1 nonmineral1 vegetable1 animal1 to the mind unaided by printed words1 the different species of the same genus may be kept together except that species for which no title has been provided must go back to the subclass under which the named species are indented4 ,thus the arrangement above necessitates placing in subdivision ,balls all copper balls1 whereas indention under proximate genus metal would have brought all metal balls together4 ,in a finely divided classification1 printing of titles for all genera is not practicable2 hence great care ought to be directed toward grouping species according to the principles of arrangement herein outlined1 noting that whenever a change of basis is made1 a new genus is implied1 and that subclasses for all other species of the same genus under whatever name1 must be brought into juxtaposition as if indented under the implied genus4#aj ,bifurcate division4--,most discussions of classification make reference to the so-called bifurcate scheme of division as the only one by which exhaustive division can be surely achieved4 ,this is commonly illustrated by the ancient tree of ,porphyry4 ,by this method any subject it is desired to subdivide is first divided by writing the name of one selected species at one branch and writing at the other branch the name of the same species prefixed by ,not4 ,thus the ,agassiz classification of living beings divides them first into sensible and not sensible 7plants74 ,a botanical classification divides plants into flowering and not flowering4 ,a zoological classification divides animals into vertebrate and not vertebrate4 ,by continuing the process of division in the same manner1 the division is obviously exhaustive of the subject1 there being always a negative subdivision to receive any subsequently created or discovered species4 ,although bifurcate division has been ridiculed by some1 it is agreed by highest authority that it is the only plan of division by which one can be sure to have a consistent place for everything1 or by which one can be certain that the divisions are mutually exclusive4 ,it can be demonstrated that a classification schedule in which the relation of genera and species is shown by indentions1 if correctly formed on the principles now sought to be applied in the revision of the ,patent ,office classification1 is susceptible of conversion into a tree of ,porphyry1 while unlike the latter it is compact and wieldy4 ,utility of arrangement according to resemblances4--,the expedient of indicating kinds of relationship between several equally indented divisions by relative position has the following utility3 7#a7 ,a uniform rule is provided1 applicable to all classes1 for placing inventions that bear the relation of whole to part in subdivisions before those that bear the relation of a part to that whole1 and those that are defined by a particular effect1 product1 material1 or use before those that are defined by a function or an operation applicable generally to various effects1 products1 materials1 or uses2 whereby that portion of the schedule in which any invention belonging to any particular class should be found may be approached whether or not the investigator knows the name of the object sought for or the title of the appropriate subdivision4 7#b7 ,the substantial impossibility of dividing many branches of the useful arts exhaustively into a reasonable number of mutually exclusive or non-overlapping subclasses is compensated for2 so that when the classifier or the searcher has an invention to place or to find including two or more different kinds of characteristics1 for each of which a subdivision is provided1 but no subdivision for the plural characteristics1 it will be known that the invention should be in the subclass for that characteristic which stands before the subclass for the other characteristic4 7#c7 ,it compensates for omission of some generic titles that if written in the indented schedule would lengthen specific titles to a cumbersome extent4 7#d7 ,it provides a rule for cross-referencing where several inventions are claimed bearing to each other any of the relationships indicated above1 cross-referencing being necessary in one direction only where the matter illustrated is coextensive with the matter claimed4 7#e7 ,it definitely limits the field of search for any unitary invention in any class so arranged1 as no patented invention having the limitations imposed by a unitary claim should be found in any subclass below the subclass properly defined to receive it or those indented under it4 ,parts of such inventions may be found below or following this subclass in the same class if these parts are within the class definition1 or elsewhere in the useful arts if not within that definition4 ,the unitary invention may be found in the subclass limited to it and certain subclasses arranged above or before it adapted to receive organizations of which it may be a part4 ,a complete system of arrangement should comprise 7#a7 a display of the entire field of the useful arts in a manner to show the relation of the larger as well as of the smaller groups1--carrying the appropriate relationship as far as possible from the highest genera to the lowest species1 the arrangement being such as would bring materials most nearly alike into closest propinquity regardless of the names they may be called by4 7#b7 ,supplementary to this classification arrangement by ideas there should be an alphabetical index of subclass titles1 appropriately cross indexed1 and additional titles of various technical and trade names of things classified under subclass titles4 ,,definition4 ,definition is indispensable in any classification and is very difficult4 ,every class must be defined and all of the groups under it4 ,after definitions have been made and printed1 they are sometimes found inadequate and must be supplemented by the definitions of other classes4 ,this is unavoidable while the complete material remains unexplored4 ,definition in the strict logical sense is not to be expected1 nor is it necessary4 ,it is commonly sufficient if an explanation or comparison be made sufficient to direct the mind to the character of the contents of the group and indicate its limitations4 ,hitherto four of the five predicables of ancient logic have been mentioned1 to wit1 genus1 species1 property1 and accident4 ,in connection with definition1 the fifth predicable1 difference1 is useful4 ,to define a class1 it is sufficient1 generally1 for the purposes of office classification1 to state a peculiar property 7not an accident7 of the objects included in the class2 and to define a species under the class it is sufficient to state the name of the class plus the difference--i4 e41 with the addition of the limitations that characterize the species4#aa ,this procedure in definition is susceptible of application from the highest genus to the lowest species4 ,it is advisable to define the means included within a title without any introductory words1 such as this subclass includes inventions relating to1 etc41 treating the subclass for definition purposes as if it were a collection of concrete things1 in the same manner as in a dictionary definition4 ,,cross-,,references ,,and ,,search-,,notes4#ab ,if patents were in all respects like material objects1 cross-references and search-notes would not be necessary4 ,nails1 screws1 locks1 hinges1 and boxes are distinct things susceptible of definite separation and classification4 ,even though nails1 screws1 locks1 and hinges form part of the box1 the box is still a box1 not a nail1 screw1 hinge1 or lock4 ,for the needs of the ,patent ,office classification1 however1 although a patent for a box must be classified with boxes1 yet if a peculiar nail1 screw1 lock1 or hinge is claimed in the same patent with the box1 or even if any one of these customary accessories of boxes is illustrated1 it may be necessary to provide copies of the patent for the box in each of the several classes provided for nails1 screws1 locks1 or hinges4 ,inasmuch as every relatively complex thing is made up of relatively simple things1 it is obvious that all disclosures can not be cross-referenced4 ,any attempt to calculate the number of cross-references to be supplied if all disclosures of the subjects of invention were to be cross-referenced would show the number to be incalculable4 ,it is necessary1 therefore1 to leave to the judgment of the classifier the propriety of cross-referencing unclaimed disclosures4 ,should a patent contain a number of claims defining a number of differently classifiable inventions1 complete cross-referencing from the class in which the classification is made original into the other appropriate classes or subclasses should be effected1 unless cross-search notes or arrangement of subclasses with appropriate titles may be substituted to advantage4 ,cross-referencing or cross-search notes are made1 as a rule1 from combination class to element class1 but never or very rarely from the element class to the combination class in which it may be used4 ,thus cross-referencing should normally be downward in a schedule of subclasses4 ,search notes indicate parallel or otherwise related classes and subclasses1 and those classes and subclasses in which analogous structures having different purposes but adapted to answer broad claims may be found4 ,by arbitrary rules of arrangement such as have been referred to in the section dealing with division and arrangement1 a search may ordinarily be definitely limited to a certain number of subclasses1 even where cross-references are not made4 ,in such arrangement any given patent1 if it be directed to one invention1 may be searched in the subclass within which the definition places it or subclasses indented under it1 and in certain subclasses above1 whose titles will indicate that the invention might be included as a part of the matter defined to belong therein1 but it would never have to be searched in any subclass following and not indented thereunder4 ,,diagnosis ,,to ,,determine ,,classification4 ,each patent and each application discloses one or more means of the useful arts 7using the term means to cover both processes and instruments in the sense in which it is used by ,prof4 ,robinson71 almost always more than one1 since most new means are combinations of mechanical elements or acts4 ,in some patents and applications the disclosure is coextensive with that which is claimed2 in others there is matter disclosed but not claimed4 ,the unclaimed disclosure may be as valuable as the claimed disclosure for purposes of anticipation1 and the classification must provide for both4 ,if the claimed disclosure belongs in one class and the unclaimed in others1 the classifier must choose between two or more classes that one in which the patent or application shall be classified and those into which it shall be cross-referenced4 ,claimed or unclaimed disclosure4--,the claims of a patent are the statutory indices of that which the applicant believes to be new1 they define an invention that has been searched by the ,patent ,office and no anticipation discovered for it4 ,future action must be based on inductions from past experience2 none knows what the future lines of search will be2 the only guides for future searches are the searches of the past2 the evidence of past searches is the claims of patents2 they trace the course of invention4 ,furthermore1 a presumption of novelty attaches to the claimed matter2 no such presumption attaches to the unclaimed4 ,the law requires every patent for improvement to show so much of the old as is necessary to explain the uses of the improvement4 ,in practice much more than that is disclosed4 ,questions as to the proper placing of patents and cross-references would be diminished by the strict enforcement of ,rule #cf of the ,rules of ,practice requiring that the description and the drawings1 as well as the claims1 be confined to the specific improvement and such parts as necessarily cooeperate with it4 ,in any event both the claimed disclosure and that which is unclaimed must be taken care of1 one by cross-reference1 and the disclosure selected for cross-reference is that to which no presumption of novelty attaches4 ,this practice of placing patents by the claimed disclosure is sometimes misunderstood4 ,its chief application is in determining classification in case of disclosures involving a plurality of main classes4 ,furthermore1 the mere letter of the rule is not to be applied in preference to its spirit4 ,subcombinations claimed may be placed with the combinations1 and in subordinate type subclasses patents must be placed sometimes by claimed and sometimes by not-claimed disclosures4 ,diagnosis of pending applications4--,what has been said relates to patents4 ,the bearing of the practice of adopting the claimed disclosure as the basis of assignment of applications for examination has also to be considered4 ,two pending applications claiming the same means very commonly differ in the kind and extent of disclosure4 ,one application may disclose several inventions4 ,which of the several disclosures shall be selected as the mark by which to place the application8 ,for instance1 the typical wire-nail machine has a wire-feeding mechanism1 a shearing mechanism1 an upsetting 7forging7 mechanism1 side-serrating mechanism1 and pointing mechanism2 it may also have a counting mechanism1 a packaging mechanism1 an electric motor on its frame for furnishing power2 and1 in addition1 numerous power-transmitting and other machine parts1 such as bearings1 oil-cups1 safety appliances1 etc4 ,the applicant may have made a complete new organization of nail-machine and may seek a patent for the total combination4 ,he may have invented a new shearing mechanism and have chosen to show it thus elaborately in the place of use he had in mind1 or he may have designed a new counter or a new oil-cup or a new power transmission1 or even a new motor1 and have given his invention this elaborate setting4 ,the shears1 the counter1 the oil-cup1 the power transmission1 and the motor are separately classifiable in widely separated classes4 ,how shall the application be diagnosed for determining its place in the office classification8 ,when the specification and drawing disclose 7as most of them do7 several subjects matter of invention1 though claiming only one1 which of those several subjects matter shall control the classification8 ,the most natural procedure1 at first thought1 would be to classify on the totality of the showing1 in which case the application for the nail-machine1 supposed above1 would be assigned to nail-making4 ,but imagine the invention claimed by an applicant to be the counter4 ,then the examiner in charge of nail-making would have to search the class of registers with which he is not familiar4 ,suppose applicant ,no4 #b files an application for the same counter which he illustrates and describes in connection with a bottle-filling machine1 and that1 classifying on the totality of the showing1 this goes to the division that has the class of packaging liquids4 ,now both the examiners in charge of bottle-filling and nail-making1 knowing that counters are classified in registers1 search the class of registers and also the pending applications in registers4 ,after these examiners have made their searches1 suppose applicant ,no4 #c files an application for the same counter1 which he says may be used for counting small articles produced by automatic machines4 ,perhaps he shows the counter attached to a piece of conventional mechanism representing any manufacturing machine1 mentioning1 say1 a cigarette or pill or cartridge-making machine4 ,it has not occurred to either the the examiner of nail-making or the examiner of bottle-filling that the other might have any such application2 nor does it occur to the examiner in charge of registers to search nail-making or bottle-filling4 ,as the specification of the counter application mentions cigarette1 pill1 and cartridge-making machines to which the counter may be attached1 the examiner in charge of registers may search those classes4 ,suppose that the counter proves to be new1 and each of the three examiners allows a patent4 ,here now are three patents for the same thing4 ,of course1 after allowance1 the counter and all other disclosed inventions that give any suggestion of novelty are cross-referenced2 but the primary purpose of a patent office classification 7to aid in determining patentability7 has failed in this instance4 ,in the imagined situation respecting pending applications1 without doubt diagnosis and classification upon the invention claimed is necessary to effect the purpose of the office classification4 ,cross-referencing after issue can not undo that which has been done4 ,if no application save that of the nail-machine be pending1 no duplication of patents occurs1 but the labor of search is increased by reason of the unfamiliarity of the examiner with the inventions he has to search4 ,after the patent is allowed he may find the entire combination of the nail-machine without the counter disclosed in a patent for a nail-making machine1 so that as a nail-making machine this new patent is of no value as a reference4 ,very probably all of the other inventions illustrated 7except the counter7 are also old in their respective classes2 but the examiner of nail-making can not tell this without extensive searches in those classes1 so he notes cross-references for them all4 ,difficulties due to varying ideas of claims4--,very troublesome questions are constantly arising as to whether an invention should be classified in a combination class or an element class4 ,the point will be illustrated by example3 ,a describes and illustrates an automobile having an internal-combustion motor and a friction-clutch in the motor transmission-gear4 ,he states that the clutch is in the usual relationship to the motor and gearing1 but claims a new clutch for whatever it may be adapted4 ,b discloses an internal-combustion motor said to be for automobiles with transmission-gearing and a friction-clutch and claims in an internal-combustion motor a friction-clutch1 etc41 specifying the form of the clutch4 ,c makes the same disclosure1 but claims an internal-combustion motor having a specified clutch1 while ,d1 with the same disclosure1 claims the combination with the internal-combustion engine of an automobile of a specified friction-clutch4 ,e claims and illustrates only the friction-clutch4 ,should these be classified together8 ,if so1 in what class8 ,should a bearing composed of a specified alloy of copper1 tin1 and antimony1 be classed as a bearing or as an alloy8 ,should a house painted with a mixture of linseed oil1 lead oxid1 and barium sulphate go to buildings or coating compositions8 ,a lamp-filament of titanium and zirconium with electric lamps or with alloys8 ,a building-block of cement1 lime1 sand1 and carborundum1 with building-blocks or plastic compositions8 ,whether these be diagnosed as combinations or as elements and compositions respectively1 and classified accordingly1 criticism will be aroused4 ,the point in view is that although principles of patentability must be considered in a classification designed as an instrument to aid in determining patentability1 convenience and accuracy of search and avoidance of voluminous cross-referencing may necessitate some arbitrary rule of classification to meet various and changing theories applied to the drafting and allowance of claims4 ,from the foregoing it will be evident that classification involves orderly logical processes of induction 7supplemented by hypothesis71 of definition and of deduction4 ,after gathering a large number of facts generalizations are made from them and a hypothesis is found to be confirmed or modified by more extended research2 the divisions are then defined2 by correct diagnosis of other instances 7as other patents7 deductions may be drawn respecting the appropriate place for them in the classification4 #a ,an art1 in the sense of a single unitary invention1 is a synonym of process1 method1 and operation4 ,the term art is ambiguous in popular usage4 ,in the phrase useful arts in the ,constitution1 it denotes the area of endeavor to which the patent laws apply4 ,when the word art is used to specify some fragment of the useful arts1 it commonly raises different notions in different minds4 ,it may be correctly used to designate any division of the useful arts4 ,it is as proper to speak of the art of grinding or the art of molding as of the art of metal-working or the art of brickmaking4 #b ,a use is an application of a means to substance to produce an effect which may or may not be the necessary effect of the means in its normal operation4 ,a catalytic may be used to ignite gas or to convert oleins into stearines4 ,an ice pick may be used to hold a chalk line or prick holes in leather1 etc4 #c ,by natural law in the useful arts is meant that uniformity of action which is manifested whenever any particular substance in any particular condition is brought into such relation with any particular manifestation of energy that the force exerted modifies or prevents modification of the form1 nature1 condition1 or locus of the substance or modifies the manifestation of energy or both4 #d ,a property may be described as any quality common and essential to the whole of a class but not necessary to mark out that class from other classes4 ,thus1 all wheel tires may be said to possess annularity2 but washers and finger rings are also annular4 ,a peculiar property is one that not only always belongs to a class of objects but belongs to that class alone2 thus a circle has the peculiar property of containing the greatest space within a line of given length1 and catalytic substances have the power of setting up chemical reaction without themselves being changed4 #e ,an accident is any quality that may indifferently belong or not belong to a class without affecting the other qualities of the class4 ,that a man's name is ,james is an accident telling nothing of the man's physique or character4 #f ,effect or result is the consequence of a process of the useful arts practiced with or without instruments4 ,the effect of an instrument is the effect of its operation4 ,effects may be direct or indirect1 proximate or remote1 necessary or accidental4 ,product is an effect consequent upon a process that changes the form1 state1 or ingredients of matter perceptibly and permanently1 as distinguished from effects that are fleeting or involve no change in perceptible form1 state1 or ingredients of matter4 ,function is the action of means upon an object while producing the effect4 7,robinson47 ,functions may be direct or indirect1 proximate or remote1 necessary or accidental4 ,the direct1 proximate1 or necessary function of the hammer in normal operation is impacting4 ,indirect1 remote1 or accidental functions of a hammer may be comminuting1 forging1 driving1 etc4 #g ,classification of the ,sciences4 #h ,logical division is the process by which the species of which a genus is composed are distinguished and set apart4 ,physical division or partition is the process by which the parts of any object are distinguished and set apart4 ,metaphysical division is the process by which the qualities of a thing are segregated and set apart in thought4 #i ,any class of objects may be called a genus if it be regarded as made up of two or more different kinds of objects or of two or more species4 ,motors is a genus when the class ,motors is considered as divided into electric motors and nonelectric motors1 or electric motors1 spring motors1 weight motors1 current motors fluid pressure motors1 etc4 ,a genus is more extensive than any of its species but less intensive4 ,a species is any class that is regarded as forming a part of the next larger class1 electric motors being a species of motors and motors being a species of energy transformers4 ,a species is more intensive than the genus to which it belongs but less extensive4 ,every species may be a genus to another species until no further subdivisions can be made4 ,this last indivisible species is termed the infima species4 ,every genus may be a species to another genus until a point is reached where no further generalization may be made or the summum genus is attained4 ,in the ,patent ,office classification of the useful arts1 the summum genus is useful arts4 ,the summum genus of the plastic arts would be plastics4 ,the infima species in the useful arts evidently never can be attained4 ,proximate species and proximate genus indicate1 respectively1 those species that are divided from a genus without intermediate genera1 and those genera from which the species are directly divided4 ,motors1 and not energy transformers1 is the proximate genus to the species1 fluid motors1 electric motors1 etc41 while fluid motors1 electric motors1 etc41 and not steam engines1 alternating current motors1 etc41 are proximate species to motors4 #aj ,in the ,manual of ,classification of the ,u4 ,s4 ,patent ,office the arrangement of subclasses has always been alphabetical1 although in the ,supplement containing definitions of revised classes the arrangement is numerical4 ,if the latter schedule of ,balls in the text had been printed in alphabetical order1 it is apparent that the species ,aluminum and ,zinc of the genus ,metal would be as widely separated as possible4 ,in the former schedule of ,balls1 in which the genus ,metal is printed1 ,aluminum and ,zinc come together4 ,it is apparent that in an alphabetical arrangement allied species can not be kept together without printing every proximate genus4 ,this fact1 among others1 indicates the advisability of abandoning the alphabetical arrangement in the classification manual and adopting the idea arrangement in the schedules of revised classes1 supplemented by a consolidated alphabetical index of all subclasses4 #aa ,a species contains all the qualities of the genus and more4 ,these additional qualities form the difference4 ,the electric motor has the qualities that are common to motors and is differentiated by reason of the fact that electric energy is thereby converted to mechanical motion4 #ab ,classification of a patent is said to be original in the class and subclass which receives the most intensive claimed disclosure1 and in which the patent is indexed in the official classification indexes4 ,original classification is referred to as opposed to classification by cross-reference4 ,a cross-reference is a copy of a patent placed in a subclass other than that in which the classification is made original1 in order to make available for search inventions disclosed therein and additional to that by which the patent has been diagnosed and classified4 ,a digest cross-reference is a cross-reference formed from abstracts or extracts from a patent consisting of illustration and text cut from a photolithograph of a patent and mounted4 ,a search-card is a sheet of the size of a photolithograph of a patent placed with the photolithographs of patents forming a subclass in the examining division and public search room1 and containing suggestions for further search1 and on the copy for the search room1 a definition of the subclass4 ,search notes are addenda to class and subclass definitions comparing other classes and subclasses with the one defined and giving directions for search when necessary to prosecute search beyond the defined class or subclass4 7,c7 ,,rules ,,of ,,classification4 ,,basis ,,of ,,classification4 7#a7 ,the basis of subdivision and assemblage of the means of the useful arts in the ,patent ,office classification is art within the meaning of art in section #dhhf1 ,revised ,statutes4 ,the direct1 proximate or necessary art1 operation or effect1 rather than some accidental and remote use or application1 should be selected4 ,in all cases qualities or characteristics that persist through all accidental uses and that can be identified as permanent are to be preferred4 7#b7 ,the operative1 instrumental1 or manipulative arts1 including machines1 tools1 and manufacturing processes1 should be classified according to whether a single operation of one kind applicable to various materials to be used for various purposes is carried out by the claimed means1 or whether plural operations are performed1 which1 combined1 produce a special effect or special product4 ,example3 ,an instrument performing a plurality of operations peculiar to shoe-manufacture would be classified on the basis of shoemaking1 because that instrument would be incapable of other use1 while an instrument peculiarly adapted to drive nails would be classified on the basis of nailing1 whether for nailing shoe-heels or other objects1 and a hammer would be classified on the basis of its function as an impact tool even though described as for driving nails1 and even into shoe-heels4 7#c7 ,structures 7passive instruments7 will1 in general1 be classified on the basis of structure1 either of special or general application1 the essential functions and effects of static structures being resistive or the maintaining of forces in equilibrium4 ,example3 ,a structure recognized as peculiar to barriers of the kind known as fences would be classified in the special class of ,fences1 but posts1 joints1 beams1 etc41 recognized as having use in general building1 even though described as used in fences1 would be classified in a more general building class1 such as ,wooden ,buildings or ,metallic ,building ,structures4 7#d7 ,compositions of matter and manufactured or formed stock or materials will be classified in accordance with the inherent character of the substance or material where possible1 otherwise according to special use4 ,example3 ,a pure chemical is expected to be classified on the basis of its chemical structure and constituents1 even though useful as a food1 medicine1 dyestuff1 explosive1 etc41 and alloys on the basis of metallic composition1 even though used for bearings1 coins1 tools1 etc42 whereas a physical composition having no reason for existence except to function as a cleansing composition or a paint might have to be classified on the basis of its function as a detergent or a coating composition1 respectively4 ,also a bimetallic layered foil1 plate1 or wire would be expected to be classified as metal stock even though designed for use for dental filler1 plowshare1 or electric conductor1 and a woven textile fabric as a fabric even though described as used for a filter or apron for a paper-making machine4 ,,division ,,and ,,arrangement4 7#e7 ,the divisions or subclasses of a class should be made exhaustive1 i4 e41 they should be susceptible of receiving any future invention that may fall within the scope of the class4 ,the rule as usually phrased is3 ,the constituent species must be equal1 when added together1 to the genus4 ,exhaustive division may be secured by maintaining always a residual or miscellaneous subclass4 ,the miscellaneous subclass represents the remainder of the original undivided material undefined except as the class is defined and may be accurately treated as if it had the class title4 7#f7 ,a second rule respecting the subdivision of a class is3 ,the constituent species must exclude each other4 ,that is1 the divisions or subclasses must not overlap4 7,see exception in ,rule #h47 ,example3 ,if a number of balls of several different materials1 several different conformations1 or constructions1 several different colors1 were to be divided into glass balls1 hollow balls1 and red balls1 this rule would be violated1 because some balls would be glass1 hollow1 and red4 7#g7 ,a third rule respecting subdivision is3 ,the divisions must be founded on one principle or basis4 ,the application of this rule will generally form divisions that do not overlap4 7,see exception in ,rule #h47 ,example3 ,if a number of balls of several different constructions1 several different materials1 and several different colors were to be classified so as to provide a place for each kind of characteristic1 they should be divided first1 for example1 according to construction into hollow balls and solid balls1 each of these according to materials into glass balls1 rubber balls1 metal balls1 wooden balls1 etc41 and each of the latter into red balls1 blue balls1 green balls1 etc4 7#h7 ,when it is found that division into overlapping subclasses and on different characteristics is a lesser evil than an unwieldy number of subclasses that would otherwise result1 then those subclasses based on characteristics deemed more important for purposes of search should precede in the list of subclasses those based upon characteristics deemed less important4 7,see ,rule #f47 7#i7 ,in arrangement of subclasses or subdivisions the miscellaneous groups containing material not falling within any of the specifically entitled subclasses1 should stand first2 those subclasses defined by effect or special use should precede those defined by function or general use2 those containing matter that is related to the matter of other subclasses as whole to part should precede those subclasses that contain the part2 and those defined by a characteristic deemed more important or significant for search purposes should precede those defined by characteristics deemed less important4 ,whenever superior rank has been assigned to any selected characteristic by placing divisions based upon it in advance of divisions based upon other characteristics1 this superiority should be maintained throughout4 ,example3 ,a partial schedule of ,class #hj follows to illustrate the arrangement of subclasses3 ,class #hj4--,,metal ,,rolling4 #a4 ,miscellaneous4 #bd4 ,die rolling-- #b4 ,heating and rolling4 #be4 ,oscillating rolls4 #c4 ,cutting and rolling4 44 444 #d4 ,drawing and rolling4 ,mills-- #e4 ,annular bodies4 #cb4 ,coiling4 #f4 ,screw threads-- #cc4 ,work reversing4 #g4 ,concave and roll4 #cd4 ,three or more coacting rolls4 #h4 ,platen rolling-- #ce4 ,continuous-- #i4 ,dies4 #cf4 ,inclined trains4 #aj4 ,rods and wires4 44 444 #aa4 ,tubes-- #da4 ,roll cooling and heating4 #ab4 ,idle rolls4 #db4 ,cooling beds4 #ac4 ,axial rolling4 #dc4 ,feeding-- #ad4 ,segmental rolls4 #dd4 ,tables4 #ae4 ,skelping4 44 444 #af4 ,wheels and disks4 #ee4 ,housings4 #ag4 ,reworking4 #ef4 ,roll adjustments-- #ah4 ,concave and roll4 #eg4 ,relief devices4 #ai4 ,platen and roll4 #eh4 ,rolls-- #bj4 ,platen rolling-- 44 444 #ba4 ,disk platens4 #fj4 ,processes-- #bb4 ,axial rolling-- 44 444 #bc4 ,pattern rolls4 #ff4 ,flanged bars4 ,in this schedule the miscellaneous subclass is numbered #a1 then follow three subclasses 7#b-d7 of rolling plus another function1 then four major subclasses 7#e-af7 of rolling1 merely1 but applied to blanks of special form producing special products1 then one special subclass 7#ag7 based upon a special class of material treated1 then five subclasses 7#ah-ca7 specialized in type and mode of operation1 then general types of rolling mills 7#cb-dj71 then various parts and accessories 7#da-ei71 then processes 7#fj-ff74 ,this is the usual arrangement and is an exhaustive division for the art of metal rolling4 ,had there been miscellaneous subclasses for all combined operations of rolling plus some other function1 a miscellaneous subclass for all mere rolling machines1 either special or general1 and a miscellaneous subclass for all parts and accessories1 the requirements of exhaustive division would have been also satisfied4 ,in the illustrative schedule1 there being no miscellaneous subclass for means having combined functions of rolling and another1 any patent having claims for the combination of a means for rolling and a means for cooling would fall in subclass #a1 ,miscellaneous4 ,in that subclass would also fall all ,mills1 such as for rolling spiral conveyer-flights1 the same not falling under any of the subclasses #cb-dj1 no miscellaneous subclass of ,mills and no special article-rolling subclass having been provided2 also all parts or accessories1 such as a water-cooled screen1 peculiarly adapted to rolling-mills1 there being no existing subclass of screens therein and no miscellaneous subclass of parts4 ,the arrangement of subclasses in ,class #hj requires that the combination of a furnace and a rolling-mill shall be placed in subclass #b1 even if the combination be designed and adapted for rolling annular bodies 7subclass #e7 or tubes 7subclass #aa74 ,means special to rolling a tube between a concave and roll must be placed in subclass #ac rather than in subclass #ah4 ,a work-reversing mill must be placed in subclass #cc rather than in subclass #cd even though it have three or more coacting rolls4 ,the rolling of ,screw-threads having been given higher rank than a ,concave and roll mechanism1 any concave and roll mechanism limited for use in rolling screw-threads should be formed into a subclass indented under ,screw-threads and not into a subclass ,screw-threads indented under ,concave and roll4 7#aj7 ,class schedules are arranged with certain subclasses appropriately indented according to a commonly understood expedient4 ,in a properly indented schedule subclasses in column at the extreme left are the main species 7the proximate species7 of the class4 ,the titles and definitions of all subclasses proximate to the class 7at extreme left7 must be read with the title and definition of the class1 as if indented under the class title one space to the right2 so also with the titles and definitions of subclasses indented under other subclasses4 ,if a title has no number 7as in ,class #hj1 ,mills71 it represents merely a subject-matter to be divided1 assumed to have no representatives other than those in the species indented under it4 ,if a title having indented species under it has a number1 it not only represents a subject to be divided but also a subclass including all other species not falling within the indented titles4 ,indention does not indicate superiority or inferiority1 but merely that the title and the definition of the indented subclass must be read with the title and definition of the subclass under which it is indented4 ,a title selected in a scheme of subdivision to be of first importance and placed1 therefore1 in advance1 should not thereafter be indented under a title selected to be of secondary importance and1 therefore1 having a lower position4 7,see ,rule #h47 7#aa7 ,a group of material may be divided on several different bases4 ,use or purpose or object treated may be adopted only when the use or purpose or object treated stamps upon the invention such peculiarities of operation or construction as to limit the applicability of the invention to the use or purpose named4 7,see ,basis of ,classification1 ,rule #a47 ,a group based upon mode of operation also may be divided into subclasses 7#a7 with a functional title1 usually participial in form1 and adapted therefore to receive machines1 processes1 and tools2 7#b7 with special use1 purpose1 or object-treated title containing the name of the use1 purpose1 or object2 7#c7 with type title1 usually a name or a name with a qualifying adjective2 7#d7 with a title of a part or subcombination1 also a name4 ,example3 ,in ,class #ij1 ,gear-,cutting1 ,milling1 and ,planing1 are to be found subclasses entitled ,gear-cutting1 certain machines being peculiar to that use2 also other subclasses with the general functional title ,planing1 subordinate to which are the special use subclass ,planing1 ,soft metal1 and the type subclass ,planers divided into two coordinate subclasses1 ,reciprocating bed and ,reciprocating cutter1 and several subordinate part subclasses1 including ,tool-feeds and ,tool-heads4 ,the adjective form of the title ,planers1 ,reciprocating bed1 indicates a type subclass4 ,if the title had been ,planers1 ,reciprocating beds1 the indication would be that the subclass was a part subclass to receive planer beds only4 ,in the class referred to for illustration1 ,tool-feeds and ,tool-heads indicate subclasses for parts and not for types of planers having tool feeds4 7#ab7 ,in arranging the divisions of a class1 such arrangement should be sought as will minimize the need of cross-references4 ,search for any particular matter can not always be limited to one group without such extensive cross-referencing as would in some cases defeat the purpose of classification4 ,forming the subdivisions of a class according to the total similarities of the inventions1 rather than according to some selected more or less important characteristic1 and arranging them in the correct order of superiority and inferiority1 with care to maintain throughout the schedule the relative positional values of the several selected bases of division1 will ordinarily in a closely bonded class limit the search for any single invention to the subclass particularly suited to receive it and some subclasses preceding that one1 excluding from the necessity of search the subclasses succeeding4 ,example3 ,in ,class #hj1 ,metal-,rolling1 it would not be expected to find any tube-rolling mill lower in the schedule than the tube-rolling subclasses1 but a tube-mill might be found higher up in ,heating and rolling1 ,drawing and rolling1 etc4 ,no concave and roll combination should be found succeeding the subclass of ,concave and roll1 but it may be found under subclasses above1 such as ,tubes1 ,screw-threads1 etc4 ,no rolls should be found lower than the subclass of ,rolls1 but they may be found in many subclasses above4 ,,definition4 7#ac7 ,having some knowledge of the nature of the materials about to be classified1 a tentative definition of a class to be formed may be framed1 which may be either written down or merely carried in mind1 to serve as a tentative guide4 ,this tentative definition must be considered as subject to change to any extent by the fuller knowledge obtained by careful consideration of the material4 ,after a full knowledge of the materials to be classified has been acquired1 it will be necessary to frame a careful definition of the class1 and also of each subclass whose title does not unequivocally indicate what is contained in it4 7#ad7 ,a definition of any class should state the qualities and circumstances possessed by all the objects that are intended to be included in the class and not possessed completely by any other objects4 ,a proper definition should not ordinarily contain the name of the thing defined4 ,definitions in a circle are1 of course1 worthless4 ,a definition should be exactly equivalent to the species defined and should not be expressed in obscure or ambiguous language1 but should employ terms already defined or perfectly understood4 ,it should not be in negative form where it can be affirmative4 ,if the class of objects has a peculiar property1 the naming of that may serve as a definition4 ,if no peculiar property can be detected1 the definition should name more than one quality or property4 ,several different classes may have one or more properties alike1 but as the number is increased the likelihood of there being others having the same properties is decreased4 ,the briefest possible statement of such properties or qualities as are possessed by all the objects of a class and not completely possessed by any other objects1 which will suffice to distinguish the class from other classes and determine its position in the general classification1 will be most satisfactory4 ,to define any species1 the genus having been defined1 the genus should be named and the difference added4 ,of course1 no generic definition should contain any limitation not characteristic of every species of the defined genus4 ,in seeking qualities by which to describe a genus or species1 no accident should be selected4 ,example3 ,suppose there be marked out and defined as a genus all means whereby one form of energy is transformed into another form of energy and no more1 and the genus be named energy-transformers4 ,we may then name1 as species1 energy-transformers that are motors and energy-transformers that are not motors4 ,motors may be defined by merely naming the genus energy-transformers1 and stating the difference1 to wit1 continuously transforming energy into cyclical mechanical motion4 ,then the definition will be3 ,energy-transformers that are adapted to continuously transform energy into cyclical mechanical motion4 ,the non-motor division will retain the genus definition4 ,it would not be illuminating for a searcher having little familiarity with the textile arts to look under the title ,carding and find that carding is defined as a means for carding fiber4 ,even though the first steam-engine invented had been used to run a gristmill1 the accident of its use as a part of a gristmill would hardly warrant the definition of a steam-engine as a means to grind corn4 ,nor would a hammer be properly defined as an instrument to drive nails or to crack nuts or to forge horseshoes1 even though a patent should not mention any use other than one of these and should lay heavy emphasis on the special value of the hammer as a nut cracker1 nail driver1 etc4 7#ae7 ,in those cases where the title is so obvious that definition is superfluous1 explanatory notes may be substituted and will usually be found helpful4 ,,cross-,,references ,,and ,,search-,,notes4 7#af7 ,inasmuch as nearly every patent discloses unclaimed matter that is classifiable separately from the claimed matter1 it is clearly impossible to cross-reference every disclosure of every means in every patent4 ,many things must be taken as conventional1 obvious1 or well known1 and the good judgment of the classifier is bound to be exercised in cross-referencing matter disclosed but not claimed to be the invention of the patentee4 7#ag7 ,a mere part or element should rarely be cross-referenced from an element class to a superior combination class4 ,an element forming part of a combination in a superior class should1 if claimed1 be cross-referenced to the element class and also if not claimed if it seems to be not merely a conventional form1 and patents having claims for more than one differently classifiable invention should always be cross-referenced unless such an arrangement of subclasses with search-notes is substituted as will guide the searcher to all places where the material may be found4 ,claimed matter additional to that which controls the classification1 if belonging in the same class1 should be cross-referenced into a succeeding subclass4 ,cross-references of unclaimed disclosure may be in either direction4 7#ah7 ,to supplement or take the place of cross-referencing1 more or less elaborate search-notes are needed1 giving directions and suggestions for further search1 setting out the relationship between classes and subclasses1 and drawing distinctions by example4 ,search-notes should indicate other classes or subclasses in which the subject-matter of the group to which the search-notes are appended is likely to form a part of a more intensive combination1 also analogous matter that might serve as a reference for a broad claim4 ,they need not1 in general1 indicate where parts or elements of the subject-matter which are common also to other classes can be found1 because the index of classes contains the necessary information4 ,for example1 it is not necessary in every machine-class to indicate by search-notes where machine-elements and static parts may be found1 nor in a class of wooden boxes to point out where the nails1 screws1 hinges1 or locks that may form a part of the box are classified4 ,,diagnosis ,,to ,,determine ,,classification4 7#ai7 ,inasmuch as nearly every patent contains disclosure that is claimed and also disclosure that is not claimed1 it has been deemed advisable to establish the general rule that where the claimed and unclaimed disclosures are classified in different classes or subclasses the invention both disclosed and claimed shall determine the placing of a patent 7or a pending application7 rather than any selected invention that may be disclosed but not claimed4 ,not claimed covers means that may form an element only of a claim as well as means not referred to in any claim4 7,see exceptions in ,rules #ba to #bb inclusive47 ,example3 ,a patent discloses and claims a dash-pot but illustrates it in such relation to a metal-planing machine as to utilize it for checking the movement of the bed at one end of its path1 or in connection with an electric generator to aid in effecting the brush adjustment2 the patent should be classified in the subclass of ,dash-pots4 ,if the classifier finds the disclosed organization of dash-pots and planer or dash-pot and generator more than a conventional illustration of an obvious use1 he should note a cross-reference to ,planers or ,electricity1 ,generation4 ,a patent discloses an internal-combustion engine associated with a specific form of carbureter2 the claims relate to the engine parts only2 the class of ,internal-,combustion ,engines should receive the patent1 and a cross-reference should be placed in ,carbureters4 ,a patent discloses and specifically claims the combination of a rail-joint comprising abutting rails1 fishplates1 and specific bolts2 the patent goes to an appropriate class of rail-joints1 and if the bolt is more than a mere obvious conventional bolt1 a cross-reference should be noted for the appropriate subclass of ,bolts4 7#bj7 ,the totality of the claimed invention should be selected when possible to determine the appropriate class in which to place a patent4 ,the entire expression of the invention will usually be set forth in the most relatively intensive claim4#a ,in a properly drawn patent there is at least one claim that will serve as a mark to indicate the classification of that patent4 7#ba7 ,where a patent discloses but does not claim a combination of proper scope to be classified in a combination subclass and claims merely a detail classified in a subclass lower in the schedule1 both in the same class1 if the subclasses are so related that the combination always involves the detail so that a search for the detail must necessarily be made in the combination subclass1 the patent may be placed in the combination subclass4 ,this avoids the need of a cross reference into the combination subclass1 and a lack of a copy in the detail subclass is immaterial1 as it is seen in the completion of the search through the combination subclass4 7,see ,rule #ai47 ,example3 ,a patent for a saw-making machine discloses dressing1 jointing1 and gaging mechanisms2 it claims dressing and jointing only4 ,there is a subclass for dressing1 jointing1 and gaging1 and a subclass for dressing and jointing4 ,in this case the patent may be placed in the first-mentioned subclass1 as that must be searched always when the second-mentioned one is searched1 cross referencing in this situation being of little value4 7#bb7 ,where a subclass with a generic title has indented thereunder a species type-subclass bearing the title of the generic subclass qualified by a difference1 any patent which claims an invention falling within the genus subclass and discloses the qualification of the species type-subclass should be classified in the latter whether or not the entire disclosure is claimed4 7,see ,rule #ai47 ,example3 ,class #bi4--,,metal ,,working4 ,machine chucks and tool sockets-- ,cam closing-- #abf4 ,scroll-- #abg4 ,bevel pinion or ring4 ,if a patent claimed only the scroll of a scroll-chuck1 but disclosed it in connection with a bevel pinion and ring1 it should be classified in subclass #abg1 ,bevel pinion and ring1 and not in subclass #abf1 ,scroll1 although if there were no disclosure of the bevel pinion and ring it would go in subclass #abf4 ,any search for scrolls must be prosecuted through all subclasses that include ,scroll in the title4 7#bc7 ,where1 as in the case of patents that show and claim a combination that as matter of common knowledge is not new except in one of its elements1 to classify a patent strictly in accordance with rule would result in placing the patent where it would serve no useful purpose as a reference and having to cross-reference it to a class where it would serve a useful purpose1 it is best to classify the patent in the class to which the element would take it4 7,see ,rule #ai47 ,example3 ,a patent claiming a wheeled vehicle1 broadly1 in combination with an internal-combustion engine comprising a cylinder1 a crank-case1 a piston and suitably-connected crank1 a valve opening into the crank-case1 and a valve in the piston opening into the cylinder1 may be advantageously classified as an internal-combustion engine notwithstanding the alleged invention is for a motor vehicle4 7#bd7 ,in order to meet the situation respecting the classification of those patents that indiscriminately claim an article of manufacture defined only by the material of which it is made and those patents that claim those materials1 leaving to the specification information regarding the designed uses1 patents for articles defined only by their ingredients specifically set forth may be placed in the composition of matter or material class4 7,see ,rule #ai47 ,example3 ,a patent having a claim for a cutter made of an alloy of iron1 tungsten1 and manganese would be classified with ,alloys2 a patent claiming a box made of paper composed of two layers united by a solution of asphaltum should go to the class of ,laminated ,fabric and ,analogous ,manufactures1 rather than to paper boxes2 and a patent for a house having its exterior coated with equal quantities by volume of carbonate of lead and oxid of barium suspended in a vehicle of linseed-oil would be classified as a paint rather than as a house4 7#be7 ,an alleged process of utilizing a specifically-defined composition or material which consists in merely applying it to the use it was designed for may be classified as a composition or material rather than as a process4 7,see ,rule #ai47 ,example3 ,a process of painting the bottom of a marine vessel which consists in applying thereto a composition consisting of sulphate of copper1 powdered metallic zinc1 chlorid of antimony1 and hyposulphite of soda1 in a vehicle of linseed oil1 would be more usefully classified as an antifouling paint than as a ship1 as the invention would hardly be distinguishable from a paint claimed as such and described for use on submarine surfaces4 7#bf7 ,an alleged process consisting merely in the use of a particularly-defined machine or similar instrument operating according to its law of action will ordinarily be classified in the class or subclass where the machine belongs4 ,but if in addition to defining the operation of a particular machine the claim also specifies acts not performed by the machine1 the classification should be in the class or subclass in which the process belongs4 7,see ,rule #ai47 ,example3 ,thus a claim for a method of rolling an iron plate which consists in passing an iron blank between a pair of rolls arranged horizontally in juxtaposition one above the other and geared together so as to rotate in opposite directions1 and causing an idle roll supported in bearings on the roll-housings to bear against the central portion of the surface of one of the first pair of rolls on the upper side thereof1 should be classified as a rolling-mill1 while if to that claim were added the steps of doubling the sheet after one passage between the rolls1 again passing between the rolls1 again doubling1 and then passing the now four-ply pack between the rolls sidewise or turned #ij per cent to the direction in which it had previously been fed1 the classification should be with processes of sheet-metal manufacture4 7#bg7 ,in the absence of settled rules defining permissible joinder of inventions1 there may be in one patent claims for one or more or all of the classes of invention named in the statute1 to wit1 machine1 art1 manufacture1 and composition of matter4 ,there may also be claims to several more or less related inventions in the same statutory class of invention but each belonging to a different industrial art4 7#a7 ,where different main classes are involved1 the patent will be classified by the most intensive invention1 without regard to the statutory class to which it belongs4 7#b7 ,where different subclasses of the same class are involved1 the patent will be classified in that one of the several subclasses defined to receive the several inventions which stands highest in the schedule of subclasses4 7#bh7 ,where a patent contains claims for all or a plurality less than all of the statutory classes1 the general rule of preference or superiority of the several classes of subclasses is that represented by the following order1 to wit3 7#a7 ,machine 7or other operative instrument72 7#b7 ,art2 7#c7 ,manufacture2 7#d7 ,composition of matter4 ,this order is1 in a general way1 the order of intensiveness of the several kinds of invention4 7,see ,rules #bi-ce47 ,example3 ,an automatic screw-machine1 peculiarly adapted to carry out a process of making a novel form of machine-screw out of a new iron alloy1 and having a claim to the machine1 to the process1 to the screw1 and to the alloy1 would be assigned to ,metal-,working1 ,combined machines1 and1 if all claims were allowed1 cross-referenced to ,bolt and rivet-making processes1 to ,bolts1 and to ,alloys4 ,if the claim to any one or two of the subjects were eliminated1 the order of preference or superiority and the order of cross-referencing would remain the same4 7#bi7 ,patents containing a plurality of claims for several different statutory kinds of invention that are classifiable in different main classes1 and wherein the rule of relative intensiveness varies from the order ,machine1 ,art1 ,manufacture1 and ,composition of matter1 may be diagnosed and classified as directed in the following paragraphs 7#cj to #ce74 7#cj7 ,where a patent contains claims for a process and for an apparatus susceptible of use as an instrument in carrying out the process1 but not peculiar to that use1 or for an apparatus adapted to carry out but one step or only a part of the process1 the process claim1 being in this instance the more intensive1 would control the classification4 7,see ,rule #bh47 ,example3 ,in a patent containing a claim for a process of roasting ore and then collecting the fumes1 and another claim for a roasting furnace that is a mere material-heating furnace1 the process claim would control2 whereas1 if one claim were for a method of roasting ores consisting of stirring the ore1 applying heat to the same1 and collecting the solids from the fumes1 and the other claim1 were for a heating furnace having a stirrer and a fume arrester1 the apparatus claim would control4 ,and if a patent contained claims for a process of roasting ores1 and other claims for a furnace susceptible of use in carrying out the process but equally useful in annealing glass or steel articles1 the process claim would control4 7#ca7 ,where a patent claims a specified article of manufacture or other product1 and also an instrument for making a part only of that specified article or other product1 the product claim1 being more intensive1 should control the classification2 so also in case of a claim for a product and a claim for an instrument performing any minor act with respect thereto4 7,see ,rule #bh47 ,example3 ,where a patent claims a particular construction of a riveted joint1 and also a tool for calking the rivet1 and where a patent claims a particular construction of shoe1 and also a buttonhook for buttoning said shoe1 the article and not the tool claims control4 7#cb7 ,where a patent contains claims to a process and a product1 the process claims govern the classification in those cases where search among machines for making the product would have to be made1 and such processes would be classifiable on the basis of the mode of operation1 usually in the same class with machines for practicing such processes4 7,see ,rule #bh47 ,example3 ,a patent having a claim for a process of making bifocal lenses1 consisting in grinding the surface of one piece of glass to form a convex lens1 heating another piece of glass until it is plastic1 then forcing the ground surface of the first-named piece into the body of the latter and gradually cooling the lens-blank thus formed2 and also a claim for a bifocal lens composed of two pieces of glass weld-united1 would be classified in ,glass-manufacture and cross-referenced into lenses4 ,or a patent having a claim to a process of making a metal plate with elongated perforations1 consisting in forming round perforations in the plate and subsequently rolling the plate1 thereby thinning and elongating the plate and elongating the openings1 and also a claim to a metallic plate having relatively long and narrow perforations1 would be classified on the basis of the process claim4 7#cc7 ,where a patent claims both process and product1 and the alleged process is disclosed in the product1 so that search would have to be made in the appropriate class of products1 the product will be adopted as the basis of classification1 and classification will be in the appropriate product class4 7,see ,rule #bh47 ,example3 ,a claim for a process of making a pencil consisting in assembling a core of graphite with a sheathing of wood1 and attaching a cap of rubber-composition to one end1 would be classified as a pencil rather than as a process1 became conception of the article is inseparable from the process and search must be made in the article class4 7#cd7 ,where a patent claims a process of making a composition of matter1 and also the composition of matter1 the claims will be classified in general in accordance with the classification of the composition of matter in all cases where the process is peculiarly adapted to produce the composition1 as by setting forth the introduction or assemblage of particular ingredients1 since those processes that include the selection of particular ingredients necessitate search among compositions having such ingredients4 7,see ,rule #bh47 ,example3 ,a patent having a claim for a composition consisting of a mixture of caoutchouc and casein1 and a claim for the process of preparing a rubberlike substance which consists in adding undissolved raw caoutchouc to casein and thoroughly mixing and kneading the mass1 would be classified according to the composition4 7#ce7 ,where a patent claims a product such as a specific article of manufacture1 or a specific composition of matter1 and also claims a process of general application for making one of the parts of the article or one of the ingredients of the composition1 the product claim should control the classification4 7,see ,rule #bh47 ,example3 ,if a patent claimed a woven textile fabric having the yarns interlaced in a defined relation1 and a process of spinning a yarn utilized in the fabric2 or if a patent claimed a varnish composed of shellac1 dissolved in wood alcohol1 and a pigment1 and also contained a claim for distilling wood to obtain the alcohol1 the product claim would control the classification in each instance1 and the process would be cross-referenced4 #a ,all terms have a meaning in extension and in intension4 ,the meaning of a term in extension consists of the objects to which the term may be applied2 its meaning in intension consists of the qualities necessarily possessed by objects bearing that name4 ,the term motors in extension means all motors--electric1 gas1 water1 spring1 weight1 etc4 ,motors in intension means instruments to convert some form or manifestation of energy into periodical or cyclical motion of a body4 ,as the intension increases the extension decreases1 and vice versa4 ,there must be more motors than there are electric motors1 and electric motors have more qualifications than are common to all motors4 ,comparison of arts and instruments with respect to their extension and intension for classification purposes should be made between comparable qualities4 ,a claim for a steam-engine may be very specific while a claim for a reaper may be very broad2 here there is no comparable relationship1 and the terms intensive and extensive do not have the relative significance most useful in classification4 ,but when a patent or application contains claims for mechanism peculiar to electric motors and other claims for mechanism common to electric motors and other kinds of motors1 the claims for the electric motor would control the classification4 7,d7 ,,procedure ,,in ,,reclassifying ,,within ,,examining ,,divisions4 7#a7 ,do not start to make a new class or revise an old one with preconceived fixed notions respecting its scope and the particular subdivisions required4 ,wait until all patents pertinent to the subject have been seen and adequate knowledge of them acquired4 ,in other words1 make no a priori classification but discover and assemble all the facts and from them make your inductions4 ,then the common characteristics of the subject-matter of the class may be intelligently defined1 the limitations of the class marked out1 and its relation to other classes set forth4 ,bear in mind that the ,patent ,office classification deals with the subject-matter of the useful arts rather than merely with existing classes1 and that it is not therefore essential to retain classes that are found to be composed of unrelated or too distantly related units4 ,assuming that the work of reclassification is undertaken by examiners who are already experienced in the subject-matter to be classified1 procedure as follows is recommended3 7#b7 ,utilizing your previously acquired knowledge of the patents in the class you are about to revise1 subdivide the existing subclasses into bundles1 so as to assemble in each bundle those patents deemed to have the closest resemblance to each other4 ,for the purpose of this assemblage1 consider each patent as an entirety and not with reference to various more or less important parts of that entirety4 ,example3 ,an apparatus comprising in alleged combination a means for decanting water1 a means for electrolytically depositing impurities1 and a means for filtering the water1 should not be classified either as a decanter1 an electrolytic apparatus1 or a filter1 but should be classified as a combination apparatus 7taking it to the general art of liquid purification74 ,so also the combination of a rotary printing-press with a folding mechanism1 and a wrapping mechanism1 should not be classified merely as a rotary printing-press1 a folding machine1 or a wrapping machine1 but should be classified as a combination of the several mechanisms as an entirety whose functions carried out in proper order produce a printed and wrapped newspaper4 7#c7 ,write an approximate or tentative definition of the matter thus assembled in each bundle and attach it to its appropriate bundle4 7#d7 ,where it appears that the subject matter of any bundle formed from the patents of any subclass is analogous to matter in other subclasses of the same class or in other classes1 a note should be added to that effect so that this matter may be given special consideration4 7#e7 ,when the same examiner or different examiners are working on different subclasses containing analogous matter1 parallel lines of subdivision should be followed wherever possible1 in order to effect an arrangement that will facilitate comparisons4 7#f7 ,when subdividing a group of more or less complex organized structures or mechanisms1 note should be taken of subcombinations that form or it is thought should form the basis of other subclasses1 either in the same or different classes1 into which those details may be collected1 either classified therein originally or by cross-reference4 ,example3 ,assuming that the combination of press1 folder1 and wrapping mechanism1 referred to in a preceding paragraph is to be classified in a class of ,printing1 on the entirety as a combination having the function of printing1 plus other functions1 and that folding and also wrapping are separately classified1 then the particular type of press should be selected to be cross-referenced into a press-type subclass of the class of ,printing1 such as ,presses1 rotary1 while the folding mechanism and the wrapping mechanism would be noted for cross-reference to other appropriate classes4 ,also1 any part of the printing press1 such as the inking mechanism1 specifically described1 should be noted for cross-reference into a subclass of ,printing designed to receive the inking mechanism as a part of the printing press4 7#g7 ,after a knowledge of the material of the class has been obtained by estimating the resemblances between the individual patents that have been assembled in the several groups1 comparison of these groups1 represented by the bundles of photolithographs1 by the aid of the approximate definitions and notes attached can be made4 ,it can then be decided whether all of these groups are to be retained in the proposed class1 and the retained groups can be organized into a class with the subclasses arranged so as to bring those subclasses having the strongest resemblances in closest relation1 and in such order as to comply with the conventions adopted in the official classification4 ,it will probably be necessary to have one subclass or group as broad as the definition of the class1 to take unclassifiable matter and to provide for possible future inventions4 7#h7 ,up to this point1 more or less cursory attention may be given individual patents2 but when an arrangement of subclasses shall have been tentatively adopted it will be necessary to consider each patent carefully to ascertain whether it is properly placed4 7#i7 ,patents that1 considered as an entirety1 cover means not peculiar to the class or subject-matter being revised1 should1 in general1 when assembled in groups as indicated1 have a note attached indicating not only want of limitation to the subject-matter of the class but also a more appropriate class to receive them if such there be4 ,although a very large proportion of patents can be accurately classified as indicated by their titles and stated uses1 the mere fact that in a patent found in a class the invention is called in the specification or claims by a name peculiar to the class is not of itself a reason for considering it peculiar to the class4 ,a gas and liquid contact apparatus may be called a heater1 a cooler1 a gas-washer1 a water-carbonator1 a condenser1 a disinfecter1 an air-moistener1 and so on1 depending upon accident of use4 ,if there are not elements in some claim to confine the means described distinctively to what it is called1 or if there are no functions necessarily implied in the means claimed peculiar to the named use1 the patent should not be kept in the class unless there is no other class in the office that can receive it4 ,example3 ,where the matter claimed is a metal beam of peculiar cross-section1 it should be classified with other metal beams1 as in ,class #ahi1 ,metallic ,building ,structures1 even if it is named in the application as a beam of particular use1 as a railroad-tie1 car-sill1 bridge-tie1 etc4 ,should a mere dash-pot be found classified in ,class #aga1 ,electricity1 ,generation1 a note should be attached indicating that it belongs in the appropriate element class4 7#aj7 ,in giving this final careful attention to the patents1 each should also be scanned to see whether it contains matter that should be cross-referenced4 ,a few lines obscurely located in a specification may contain a disclosure of a most valuable invention4 ,no class can be deemed complete until the disclosures appropriate to it found as parts of more complex inventions in other classes1 or disclosures of analogous matter in other classes1 are either cross-referenced into it or cross search-notes made4 7#aa7 ,to indicate cross-references1 from one subclass to another within the class or from the class under consideration into another class1 attach a small slip of paper to the patent and mark on the slip the subclass number in which the cross-reference shall be mounted4 ,if the matter to be cross-referenced relates only to a portion of a voluminous patent1 the portion of the specification and drawing to be cross-referenced should be indicated4 ,if the cross-reference falls outside the class1 the class number should be noted in addition to the subclass number4 7#ab7 ,should it be found that the handling of copies in making examinations detaches the cross-reference slips1 it may be advisable to mark lightly but legibly in pencil on the lower right-hand corner of the examiner's photolithograph the number of the subclass or subclasses into which it is to be cross-referenced1 or the number of the class and subclass in case it is to be cross-referenced to another class4 7#ac7 ,whether cross-reference notations are written on a separate slip or on the photolithograph1 the number of the class and subclass into which a patent is to be cross-referenced should always be preceded by ,x 7thus ,x #aja-bc7 in order to distinguish the original classification notation from the cross-reference notation and enable sorting and indexing to be done without confusion4 7#ad7 ,to indicate cross-references from other classes into the one being reclassified1 set down the number of the patent in a notebook1 placing after the number 7#a7 the class and subclass in which it is classified2 and 7#b7 the number of the class and subclass in which it is to be cross-referenced4 7#ae7 ,should new subclasses be formed or transfers of patents be determined on1 and lists of the patents1 instead of copies thereof1 be furnished clerks for the purpose of making such subclasses and transfers and correcting the official indexes and other records1 each patent should be listed by number in column to the left of a sheet of paper or notebook1 and opposite each patent number on the same sheet should be written 7#a7 the number of the class and subclass in which it is officially classified2 7#b7 the number of the class and subclass to which it is intended to transfer it2 and 7#c7 the numbers of the classes and subclasses1 preceded by ,x1 into which it is intended to cross-reference it4 ,note3 ,even though examiners engaged in reclassifying are confident of their ability to classify and arrange on better principles than those that have been applied thus far in the classification1 they ought1 nevertheless1 to follow those principles under which one-half of the patents have been classified4 ,until the ,commissioner of ,patents orders examiners to classify on other principles1 it is expected they will follow those now established4 ---------------------------------------- ------------------------- ,transcriber's ,note3 ,every effort has been made to replicate this text as faithfully as possible1 including obsolete and variant spellings and other inconsistencies4 ,for readability1 the footnotes have been moved to the end of the relevant chapter4 ---------------------------------------- -------------------------