ly copyrighted design. These registrations, particularly if brought to the attention of the proprietor of the first copyright, might hamper him in later making ordinary and obvious changes in the article produced under his design. He could be harassed with such registrations, and they might, under possible construction of the Bill, be effective to hem him in and unduly limit him in the use and enjoyment of his design.

Then too there would be the danger to the owner of a copyrighted design that subsequent registrations for identical, or substantially identical, designs might not involve originality on the part of their so-called authors, but be mere piracies. Under the Bill, the way of the pirates is not only made easier so far as infringement is concerned, but the door is left open for the unscrupulous readily to cloke themselves with copyright registration.

There are other objections, too numerous to mention.

The effect of the Bill will not be to stimulate the production of industrial designs. There will be less incentive to produce and exploit them. The monopoly rights granted will be less valuable than at present and will afford less protection against piracy. Confusion of rights would result, and provoke more litigation. It is distinctly a step backwards, and against the public interest.

While purporting to substitute copyright for patent protection for industrial designs, the Bill fails to conform to the established basis of copyright law. Instead it is a strange mixture of copyright and patent law provisions which are inconsistent and difficult to reconcile, and the true meaning of which, in their new relation, is indefinite and could only be determined after years of construction by the courts.

PRIOR ART INVESTIGATIONS.

By IVAN P. TASHOF*

The investigation of the prior art relating to a particular subject is an important piece of research work directed towards gathering information as to the state of the art. It involves a painstaking search of the U. S. and foreign patents and literature.

Illustrative examples of problems arising necessitating an investigation of the prior art will be briefly referred to. A manufacturer may desire to design a casting machine to meet his particular needs. Clearly, before attacking the problem, the prior art should, at least in a measure, be available in order to indicate what other inventors have accomplished along the same line.

Where applications for letters patent are to be filed to protect important inventions, it is frequently desirable to know the prior art in order to prepare claims which while broad, circumscribe the prior art as far as known. One of the questions which is frequently asked of counsel is, "What may we use without fear of infringement?". This question may be answered by an examination of the expired and unexpired patent art. Frequently, the unexpired patents contain disclosures which are not claimed and therefore are public property.

One of the most important objects of a prior art investigation may be the collection of information which will serve as an indication of the probable validity of the claims of a patent. This type of investigation will be discussed in detail. Before proceeding to undertake a search of the prior art pertinent to the subject matter of a patent, the history of the application upon which the patent matured should be carefully studied. The oath of the application should be examined to ascertain if foreign applications have been filed. If they have, a search should be made to locate these patents as they may have à definite bearing upon the validity of the claims of the corresponding U. S. patent. The file history of the pat

Patent Lawyer, Victor Bldg., Washington, D. C.

ent also contains valuable information which will aid the investigator in the analysis of the claims. After the file history has been examined, the next step is to carefully analyze the claims of the patent. Each claim should be carefully reviewed and its elements segregated. For example, referring to U. S. patent No. 1,465,906 to Holloway for a "Retort Door" claim 1 reading,

"1. In combination with a retort-body, a door pivotally connected thereto adapted to rotate in a horizontal plane about a vertical axis and revolve about a horizontal axis, means for limiting its movement around the horizontal axis, means for limiting its rotation in a horizontal plane, and means for locking the door in its closed position after rotation.",

may be analyzed as follows:

1. A retort body,

2. A door pivotally connected thereto adapted to rotate in a horizontal plane about a vertical axis and revolve about a horizontal axis,

3. Means for limiting its movement around the horizontal axis,

4. Means for limiting its rotation in a horizontal plane, and

5. Means for locking the door in its closed position after rotation.

Considering U. S. patent No. 1,149,580 to Hofmann & Gottlob directed to the process of producing vulcanized rubber, claim 1 reading,

"1. The process of producing vulcanized rubber which comprises incorporating with rubber a small amount of an ammonium compound having a dissociation constant greater than 1×10-8 and having a basic reaction at the vulcanization temperature, and heating the resulting product with a vulcanizing agent to effect vulcanization.",

may be analyzed as follows:

1. Incorporating with rubber a small amount of ammonium compound having,

2. A dissociation constant greater than 1X10—“, 3. Having a basic reaction at the vulcanization temperature, and

4. Heating the resulting product with a vulcanizing agent to effect vulcanization.

It will be noted that the above claim speaks in terms of a dissociation constant. Therefore, it becomes necessary to review the subject of dissociation constants in order to have well in mind the defining terms of the claim.

After having analyzed the claims of a patent, it is quite desirable to figure out the equivalents of the elements of the claim, as of course, in making the investigation, these must be considered. As an aid in reaching a conclusion as to equivalents, frequently it is desirable to review the textbooks relating to the art being investigated. In many cases, perhaps usually, the investigator knows considerably more about the art after making the search. If he had started out with the knowledge acquired during the progress of the investigation, probably he would have been in a position to make a search. In order to bridge this gap, it is quite desirable to consult the text books and acquire, as nearly as possible the history of the development of the art. An investigator cannot be expected to know the history of all the arts but it is expected, that upon being called upon to investigate an art and write an opinion upon the probable validity of the claims of a patent, he will, as far as possible, review the history of the particular art he is interested in.

After having prepared himself for the search, the next step is to make the search. A well developed fairly comprehensive search of the patent art comprises the U. S., British, German and French patents. If the investigator has familiarized himself with the history of the art, he will be in a position to know what foreign patent art offers the most fertile field of search. For example, if the search is for the purpose of determining the validity of a patent directed to the preparation of artificial dia

monds, he will know that the French have been very active in this field and consequently, the first foreign art to be examined should be the French patents and literature. Again, if the subject of investigation is dyes, he will know that the Germans have developed this art to a high degree and that the chances of finding a reference in the German patent art and literature are perhaps greater than in the arts of other foreign countries.

In making the search of the U. S. patent art, the most pertinent classes and subclasses are first examined and then the outlying classes. The examination of the most pertinent class will indicate from the cross references present where closely related art is to be found. In other words, leads are furnished which an experienced investigator will immediately follow. In making a search of the character under discussion, the investigator is searching for evidence:-evidence upon which a decision is to be reached as to the probable validity of certain claims. Therefore, he is, after a fashion, a detective. Just how good a searcher he is, in a large measure is determined by his sense for discovering leads and running them down. Many investigators are what may be termed "mechanical searchers", that is, they search the places where the art should be but in some way fail to display that "detective sense" of uncovering leads and following the same, feeling out the places where references have been misclassified or have an incidental disclosure. Such an investigator may have years of experience but never will reach the heights.

In addition to examining the patent art, for a well rounded out search, it is necessary to investigate the periodical and other literature. This presents the problem of determining what publications offer the most fertile field. If the investigator's preliminary preparation has been of the proper character, he will be in a position to determine what publications to examine.

The author has had considerable experience in making investigations of a chemical and metallurgical character. Referring to investigations of this type, he offers the following general suggestions: