ented machine or process may be used for some but not all of the purposes for which the other two may be used and then be used for still additional purposes, creates, when this same variation is carried out in hundreds or thousands of patents, such a network of interrelated structures or processes that all known systems of classification fail utterly. Frequently a single patent discloses several related features each of which would find its home in a separate subclass, and when the patent is placed in one of these subclasses the features belonging to all the others are wholly lost to view. This multiplication or crossing of species does not occur in the subjects matter of the usual scientific classifications. Foreign governments have different patent laws and their arrangements of patents are applicable in this country only to a limited extent.

Much has been said, by those interested in this subject, concerning the relative merits of a so-called "art classification," in which, for example, all patents for machines or processes for making shoes would be grouped together; all for making hats together; all for making boxes together; all for churning butter together; all for mixing paint together; all for mixing cement together, and so on. Experience has shown, however, that machines which sew cloth and leather shoes are much like those that sew cloth and leather coats or mail-bags or any of several quite different things. Likewise a shoenailing machine has much in common with a thin-wood box nailing machine. Again the felt hat machine can readily make felt boots; the rotary paint mixer is like a cement mixer, etc. These patents in one art are, under our laws, very often anticipatory references for inventions in another art.

There have been, likewise, advocates of a "structural" grouping, in which the ultimate purposes of the machines are ignored and all patents for things structurally similar are grouped together. This plan, if carried out with all the patents, would bring those for such totally foreign devices and machines together that much confusion would be inevitable. It might even bring a rotary stirrer of an ice-cream freezer and a grain harvester reel in the same class. The utter submergence of known trade, commercial and industrial names and the substitu

tion of strange structure-defining terms in the classification titles of such structural groupings could only result in mystifying searchers and leading them astray.

There have been some classes which were based on "function," as cutting, agitating, etc. These have proved useful but experience does not show the patents of the entire office could be so classified.

None of those in charge of the reclassification work has ever been able to adopt any one single system of grouping. The patents themselves have always forced a sort of combination of principles and systems. Some classes have been based on art, some on structure, some on function, some on the material worked upon, some on the product produced, and many involve combinations of all of these. Reviewing the classes that so far have been revised by the Classification Division, they reveal all these systems and varieties. Possibly if those who revised them could have been relieved from the necessity of keeping the patents always open for searching purposes, like one who repairs a railroad but must at the same time keep it constantly open to traffic, the results might have been different and better. Always, however, the classification has proceeded piecemeal, and each new class has of necessity been so made as to fit into its place. among other existing classes.

The general plan of procedure followed for about nineteen years was to have the revision of the classes carried on by assistant examiners, under the supervision of the chief of the division, in the rooms of the Classification Division. This plan proved to have several drawbacks. In the first place, these assistant examiners usually were not familiar with the classes they undertook to revise, and each consumed more time in familiarizing himself with the patents of a class, the art to which they related and its various ramifications, than was required to actually classify the patents. The progress was, therefore, exceedingly slow. In nineteen years only about sixty per cent of the classes of U. S. patents were revised. A second objection to this plan resided in the fact that there was not sufficient exchange of views between the party making the revision and the examiner who had examined the class for years and who was, presumably, much more familiar with it and its ramifications. Fin

ally, when the revision of a class was completed, it was sent back to the examiner who was more or less ignorant of what changes had been made, what patents had been added to or taken from the class, and what new lines between classes and subclasses had been drawn. A certain amount of confusion, and, ultimately, dissatisfaction and criticism resulted from this sudden precipitation of a revised class upon an already overburdened examiner. He often did not take time to fully study it. He had lost, of course, that valuable asset of knowledge, emperically acquired, which he possessed as to the old class, its contents, and its lines of cleavage. Sometimes the terms used in the subclass titles were not such as had been used before in that particular art. No one was present in the division to explain the changes to him.

In order to escape these difficulties and provide a more rapid progress, the plan of procedure was, about two years ago, changed to the following:

Where an experienced assistant examiner could be found who had examined the patents of his class for some years and was, therefore, quite familiar with them, he was directed to reclassify his class. He was to do the work, not in the rooms of the Classification Division, but in his own examining division where he could freely consult, as the work progressed, the examiner in charge of his division and any other members of that division who had knowledge of the class to be revised. The work was, however, to be done under the general supervision of the chief of classification. In order to care for the examining work, released by this assistant who was classifying his own class, one of the assistants of the Classification Division was detailed to do such examining work. He occupied a desk in the examining division near that of the assistant who was to do the classifying. These two assistant examiners, working side by side, constituted a sort of team for carrying on both the examining work and the revision work. The assistant examiner detailed from the Classification Division to do examining work had near him the other assistant examiner to consult as to the proper search for reference material, while the assistant who was actually revising his class had near him for consultation as to procedure rules and various details common to classification generally, one who had

formerly done this kind of work and was familiar with its principles. Each man, therefore, supplemented what information the other lacked..

This plan has worked out with gratifying results. As the regrouping is done with the examiner's copies of the patents and in the examiner's rooms, the searches are made in the new subclasses as they are formed and thus they are tried out in the acid test of actual examining work. The change from the old to the new class and subclasses is so gradual that those in the division become familiar with it as it progresses, and there is no longer the embarrassment resulting from the sudden dumping of a totally revised class upon an examiner who does not know what changes have been made in it. When the revised class is finally completed and made official, the assistant who made it returns to his examining work upon it, and the assistant detailed from the Classification Division proceeds to some other division to permit some other assistant examiner to reclassify his own class. This plan insures that every one having any knowledge of the class has an opportunity to present his views, and should produce a revision that is as good as the office can make. Such plan also leaves the assistant who revised the class to remain in the division where it is to be examined, to work upon it, to explain it to those about him, and to such inventors and attorneys as seek information concerning it. Further, the terms used in the titles of the groups are more apt to be those having recognized meanings in the art and the groupings seem to be along more practical lines. The most noteworthy fact, however, is that the work has progressed very much more rapidly. Although this work, like all other government work, suffered greatly by the inroads incident to the war, and although the low salaries paid the examiners have caused very many of them to leave the service, with a consequent reduction of over a third of the number engaged in reclassification, yet in spite of all these drawbacks over one hundred and thirty-five thousand patents were revised into official classes during the year 1919. It will be seen his is roughly four times the speed obtained in previous years. If this progress can be maintained all the classes of the office will have been revised in about four years.

When this result is secured the classification work will, of course, not be completed, as there are many classes revised so long ago as to need further review, and some have proved unsatisfactory in practice and will need correction; also subclasses from time to time must be further subdivided, new lines established here and there, and a new class created as an art expands. But the systematic upheaval of the entire classification of all the patents will, presumably, not again be necessary or undertaken.

The whole task is one of very great perplexity, and often, after the very best has been done that can be done within the limits of time and force permitted, the results are admittedly in some instances not wholly satisfactory.

OATH OF APPLICANT FOR REISSUE.

RULE 87

T. A. HOSTETLER, Law Examiner.

Rule 87. Applicants for reissue, in addition to the requirements of the first sentence of Rule 46, must also file with their petitions a statement on oath as follows:

(a) That applicant verily believes the original patent to be inoperative or invalid, and the reason why.

(b) When it is claimed that such patent is so inoperative or invalid "by reason of a defective or insufficient specification," particularly specifying such defects or insufficiencies.

(c)

When it is claimed that such patent is so inoperative or invalid "by reason of a defective or insufficient specification," particularly specifying such defects or insufficiencies.

(c) When it is claimed that such patent is inoperative or invalid "by reason of the patentee claiming as his own invention or discovery more than he had a right to claim as new," distinctly specifying the part or parts so alleged to have been improperly claimed as new.

(d) Particularly specifying the errors which it is claimed constitute the inadvertence, accident, or mistake relied upon, and how they arose or occurred.

(e) That said errors arose "without any fraudulent or deceptive intention" on the part of the applicant.