452 FEDEBAIi BBPORTBB. �Geo. D. Noyes, for complainant. �Wadleigh e Fish and H. S. Clark, for defendant. �LowELL, G. J. There is very little conflict of evidence in thia case. The patentee made a machine containing his invention in the year 1867, and in 1863 he substituted for it another varying in form and proportions, but not in principle. These machines he used successively in the ordinary way of his business, as a maker of card and pasteboard, until he applied for his patent, in 1876. The specification and mode! represent precisely the machine of 1863. During the time that the machines were used they stood in the room with several other machines necessary for the other processes of making, drying and coloring pasteboard, and were operated chiefly by one man, Moulton, who was sometimes assisted by one other. About 23 workmen were employed upon the other parts of the manufacture. The doors of the factory were usually kept locked, and each of the 25 workmen had a key. How many visitors came to the factory is one of the disputed points. There were occasional visitors, but not many persons came to the factory from mere curiosity. Dur- ing some months Mr. Denison, a friend of the patentee, was given the use of an upper room for making tags, and his workmen passed in sight of the pasting machine. It is not proved that any workmen, visitors, or other persons acquired or divulged a knowledge of the mode of operation of the machine, until the workman Moulton gave that information to the defendants, in 1876. �Was the invention in public use for more than two years before Perkins applied for his patent ? The time was enough. Was the use a public use? The law "desires to encourage inventors to make their discoveries kuown for the improve- ment of the art, and to discourage an extension of the mo- nopoly beyond the statutory period. For these reasons, and because of the difiiculty of ascertaining the amount of knowl- edge which may have been derived from the exhibition, pub- lication or use of the invention, it bas always been held that when the public have had means of knowledge they bave had knowledge of the invention. Thus, if a book bas been pub- ����
