balance of the fee due the Patent Office, and obtained a reissue, which recited (among other things) that said original letters patent were "granted to him upon his belief that he was a citizen of the United States, which belief arose from an ignorance of the laws of the United States:" Held, That the original and reissued patents were both invalid: the first because of the false suggestion; the second from want of power in the Commissioner to grant it. (Child v. Adams, 1 Fish., 189.) 140. OATH PRIMA FACIE EVIDENCE OF NOVELTY.-When the patent has issued, supported by the oath of the patentee, the burden of proof is cast upon the party who would object, to show that the grant has been improperly obtained by the patentee; because the law presumes, in the first instance, that the patent has been granted upon the proof which the statute requires to be laid before the officers of the Government, and that those proofs were satisfactory. (Curtis on Patents, § 472; Philadelphia and Trenton Railroad Company v. Stimson, 14 Peters, 458.) The oath forming a part of the letters patent forms a legal ground for the presumption of the novelty and originality of the patentee's claim until the contrary is proved. (Parker v. Stiles, 5 McLean, 60.) And a patent issued, grounded on the oath of the patentee, is prima facie evidence in an action of infringement. (Fultz ex parte, MS. Appeal Cases, D. C., 1853.) 141. FORM OF OATH BY A SOLE INVENTOR. Byron Rogers, the above-named petitioner, being duly sworn, (or affirmed,) deposes and says, that he verily believes himself to be the original and first inventor of the improvement in seed drills described in the foregoing specification; that he does not know and does not believe that the same was ever before known or used; and that he is a citizen of the United If the applicant be an alien, the sentence "and that he is a citizen of the United States" will be omitted, and in lieu thereof will be substituted "and that he is a citizen of the republic of Mexico," or "and that he is a subject of the King of Italy," or "of the Queen of Great Britain; or as the case may be. If the applicants claim to be joint inventors, the oath will read "that they verily believe themselves to be the original, first, and joint inventors," &c. SEC. VIII. Classification of Subjects of Invention. 142. Classification and distribution. 143. Agriculture. 144. Agricultural products, prepara tion of. 145. Builders' hardware. 146. Calorifics. 147. Carriages. 148. Chemical processes. 149. Civil engineering. 150. Clay manufactures. 151. Compositions. 152. Felting and hat making. 153. Fine arts. 154. Fire-arms. 155. Glass manufacture. 156. Grinding mills. 157. Harvesters. 158. Household furniture. 159. Hydraulics and Pneumatics. SEC. 160. Illumination. 161. Leather manufactures. 164. Metal working. 165. Navigation. 166. Paper making. 167. Philosophical instruments. 169. Printing and stationery. 171. Sewing machines. 172. Sports, games, and toys. 174. Stone working. 175. Surgical apparatus. 177. Wearing apparel. 178. Wood working. 142. CLASSIFICATION AND DISTRIBUTION.-The subjects of invention comprised in applications filed in the Patent Office are divided into thirty-six classes, some of which are subdivided into sections, and are distributed for examination among twenty-two principal examiners, each of whom has charge of a particular class or classes. The classification adopted January 1, 1868, is as follows: 143. CLASS I. AGRICULTURE.-Implements and machines for working the soil, including sowing, planting, fertilizing, digging, and gathering roots, &c., grafting, and pruning. (For Harvesting, see Class XV.) 144. CLASS II. AGRICULTURAL PRODUCTS, PREPARATION OF.-Implements and machines for preparing produce for market, including threshing, winnowing, protecting, and preserving crops and produce; fences and gates, cribs, granaries, stack-covers, and barns; incubation, culture of bees, care of domestic animals and dairy implements. 145. CLASS III. BUILDERS' HARDWARE.-Door-locks and fastenings, hinges, bell-hanging, and the metallic trimmings of houses, &c., including furniture hardware. 146. CLASS IV. CALORIFICS.-Apparatus for heating, ventilating, and cooking. (For Blast and Ventilating Fans, Bellows, &c., see Class XVII.) 147. CLASS V. CARRIAGES.-The construction of wheeled vehicles, including trucks, sleighs, &c. (For Railroad Cars, see Class XXVIII.) 148. CLASS VI. CHEMICAL PROCESSES.-Instruments and methods of evaporation, distillation, dyeing, tanning, water-proofing, vulcanizing india rubber, &c., and the manufacture of acids, salts, starch, sugar, alcohol, vinegar, dyes, paints, gas, glue, fats and oils, soaps, manures, &c. 149. CLASS VII. CIVIL ENGINEERING.-The construction of canals, roads, bridges, wharves, docks, sewers, wiers, dams, &c., and including military engineering, mining, architecture, masonry. (For Blasting, &c., see Class XII.) 150. CLASS VIII. CLAY MANUFACTURES.-The making of bricks, tiles, pottery, porcelain, and machines, tools, and kilns for manufacturing and enameling the same, including lime and cement kilns and peat machines. 151. CLASS IX. COMPOSITIONS.-Artificial substances formed by the mechanical or chemical combination of different ingredients. 152. CLASS X. FELTING AND HAT MAKING.-Methods and apparatus for felting wool, &c., and the making and finishing of hats, caps, &c., including implements and machines for the same. 153. CLASS XI. FINE ARTS.-Methods and applications of music, carving, sculpture, painting, graining, engraving, lithography, wood-cutting, &c., photography, bank-notes, &c., jewelry, including instruments and materials for the same. 154. CLASS XII. FIRE-ARMS.-Implements of war, offensive and defensive, including ammunition and its incidents, and blasting. 155. CLASS XIII. GLASS MANUFACTURE.-Glass furnaces; molding, blowing, cutting, grinding, and polishing glass, and implements and machines for the same. 156. CLASS XIV. GRINDING MILLS.-Machines for breaking, crushing, and grinding materials, including grain-cleaning, flour-bolting, &c. (For Mill-gearing, see Class XX.) 157. CLASS XV. HARVESTERS.-Implements and ma chines for harvesting and securing crops, &c. (For Hand Hay-rakes and Pitchforks, see Class II.) 158. CLASS XVI. HOUSEHOLD FURNITURE.-Articles, implements, and machines for domestic purposes. (For Culinary Utensils, see Class IV.) 159. CLASS XVII. HYDRAULICS AND PNEUMATICS.Machines and apparatus for raising, conveying, and directing water and other fluids, including bottling, and apparatus for controlling and operating air, &c. 160. CLASS XVIII. ILLUMINATION.-Implements and devices for obtaining, preserving, and regulating artificial illumination. 161. CLASS XIX. LEATHER MANUFACTURES.-Machines and tools for working in leather, and the manufacture of boots and shoes, harness, trunks, belting, and including preparatory processes, cutting, splitting, &c. 162. CLASS XX. MECHANICAL ENGINEERING.-General mechanical movements, horse-powers, lifting jacks, hoisting apparatus, mill-gearing, &c. (For Presses, see Class XXVI.) 163. CLASS XXI. METALLURGY.-The preparation and treatment of ores, reduction and purification of metals, and processes for amalgamating, electroplating, and metallic coating. 164. CLASS XXII. METAL WORKING.-Methods, machines, and tools for shaping metals; construction of machines and articles of metal; manufactured articles of metal. 165. CLASS XXIII. NAVIGATION.-The construction of vessels, sails, rigging, propelling, and steering apparatus, life-boats, preservers, rafts, &c. 166. CLASS XXIV. PAPER MAKING.-The preparation |