In every library that has a patent section, that is a part devoted to patents, there is a librarian in charge who will either find any patent you want or who will show you how to use the Index, Official Gazette and the volumes of the full specifications.
The patent attorneys in Washington have things much easier as all of the patents are bound in books according to the class they are in and they only need to look over the volumes of a given class to choose those they want.
When you have learned everything you can from books, papers and copies of patents already granted about the subject you are interested in you will have a pretty clear idea of the state of the art and whether you are working in a virgin field or one that has been sown with the same kind of inventions by others.
But there is another and most important part of the state of the art which neither you nor your patent attorneys can find out about until after you have filed your application for a patent; this is the information contained in the applications for patents by other inventors before your application was filed.
Should another application disclose either in whole or in part an invention like, or nearly like, yours, or rather that your invention is like, or nearly like, some one’s else, the patent examiner declares what is called an interference, of which more will be said in another chapter, and this gives the patent attorneys on both sides another chance to rake in a few more fees.
What to Do When You Find There Are No Other Improvements Like Yours.—After you have looked up, or have had looked up, the state of the art as carefully as possible, and you are satisfied that your invention, or improvement, is different from everything else you have been able to find, you should by all means go ahead and make such experiments, or build a working model, as the case may be, in order that you may know that all you have thought about it is really true.
As soon as your experiments are completed or your model is finished so that you know exactly what you want to claim as being strictly new and novel and original with you, then you are in shape to hire a patent attorney to draw up your patent application and file it and don’t do the latter a moment before.
A patent application based largely on what you guess, is a patent when granted without value for it can no more cover the exact facts in the case when these are finally worked out than a description one might write about an imaginary trip to Europe would be likely to fit the true details of a real trip which he would make sometime thereafter.
When You Find There is a Resemblance.—Very often you will find after you have looked up the state of the art that some other inventor has patented a device that seems on the face of it quite like yours and yet when you examine them critically, compare them closely and bring thought to bear upon them you will be able to distinguish a difference and often in several respects.