It is clear that the two patents must stand or fall together If the patent for the process is invalid, so must be the patent for the product. What we have to say will refer to the process patent. The alleged invention described in the patent is not for insulating telegraph wires, for that art long antedated the original patent. The specification disclaims as a part of the invention the braiding of a fibrous covering over the wire, and then dipping it in wax for the purpose of filling and closing the pores, and the subsequent scraping of the surplus wax from the wire. The patent does not cover the material in which the wire, after it has received its fibrous coating, is dipped, which may be either paraffine, wax, or bitumen, or any other suitable material. The three substances mentioned had long been used for that purpose. Nor does the patent specify or cover any device by which the process is to be carried on. Any suitable machine may be used. The process described by the patent consists, therefore, simply in this: After the wire has received its fibrous coating, and been dipped in paraffine, wax, or other suitable substance, the compressing and forcing of the paraffine, wax, or other substance, without scraping off any part of it, into the pores of the fibrous material by some suitable means. We think this process was not new. It was substantially anticipated both by the process described in the patent of Dundonald and in that of Baudouin, the first dated January 22, 1852, and the other April 3, 1857. Dundonald describes his process thus: 'I also employ a bituminous material to cover, and thus insulate, the conducting wires of electric telegraphs, which are intended to be placed under ground. For this purpose I employ the said bitumen, either simple or compounded, of a flexible description, and pass the wire through it when it is in a melted state, then causing the wire to pass through some die or orifice, which will deprive it of all the superfluous bitumen. * * * The incasement of this wire with bitumen may also be affected by covering it with a filamentous material, which has been previously saturated with melted bitumen, and then passing the wire so covered through a heated die or orifice, so as to melt or soften the bitumen upon the filamentous material, and press the whole of the coating against the wire in such a way as to cause it to form one compact continuous covering of the wire, and thus insure its insulation.'
The patent of Baudouin describes his process as follows: 'My invention relates to the preparation of conductors of electricity for electric telegraphs, being wires insulated to prevent the loss or deterioration of the electric currents used for that purpose, and also in the machinery for the preparation of manufacture of such conductors. I coat the wires with bituminous or such like fatty matters that are not liable to become hard or crack, but, on the contrary, are constantly acted on by the temperature of the atmosphere. Coatings of this material in themselves are insufficient to maintain the proper protection and insulation for telegraph conductors, but when c mbined with other materials, such as paper, woven fabrics of cotton, silk, wool, or hemp, in a particular manner, are well adapted for the purpose. I prefer to use three ribbons and bobbins for this purpose, the first covering of the wire being enveloped by the second in such manner that the helical junction of the first ribbon is covered by the second, and the second by the third. The wire is passed through a bath of hot bitumen, and has the superfluous matter removed by passing through suitable dies or parts to scrape and smooth its surface, and render it of uniform thickness. The first and second ribbons are also passed through bituminous or other suitable matter to render them more impervious to electricity. The coated and lapped wire is passed through suitable dies to remove superfluous matter, to smooth down the lapping of the ribbons, and to compress and cause their proper adhesion. The coated and lapped wire passes through dies or smoothing holes both in entering and leaving the rotating frame. These dies or smoothers have a rotary motion, the better to enable them to wipe and smooth the coated wire.'