PRESHO cess is adopted by many of the railway com- panies of England, and notwithstanding its expensiveness is highly approved of. Wood thus prepared is said to be also protected against the teredo navalia or ship worm. In France the process of Dr. Boucherie has been extensively employed for railway and ship timber. The material used is sulphate of cop- per dissolved in water so that at a temperature of 60 the density of the solution is about 1'006. A water-tight cap is fastened on one end of the log, and into this is inserted the end of a vertical tube, 30, 40, or more feet in height, into which the solution is poured. The hydrostatic pressure first forces out the sap, and then the solution enters the pores of the wood. Timber thus prepared at Fontaine- bleau was fully impregnated in 24 hours in lengths of 7 ft. ; but sticks of the same tim- ber 40 ft. long required 10 days for the com- pletion of the process. Another process em- ployed in both England and France is that of Mr. Payne, patented in 1841. The timber is introduced into a long iron cylinder, which is then closed air-tight; steam is driven in, ex- pelling the air through a valve, and a cold so- lution of sulphate of iron is pumped in, which condenses the steam and produces a partial vacuum. This is made more complete by the air pump, and the cylinder is then filled with the solution, which is still forced in under con- siderable pressure. In a few minutes the solu- tion is let out and the cylinder is again filled with air. This is again expelled by steam, and a solution of another salt is admitted, of such a character as will react upon the sulphate of iron, producing double decomposition and leaving in the pores of the wood an insoluble salt. Chloride of calcium answers this pur- pose, and the insoluble sulphate of lime re- mains in the wood, the chloride of iron being dissolved out. Carbonate of soda may be sub- stituted, in which case insoluble carbonate of iron is formed, the soluble salt being sulphate of soda. The process of Sir William Burnett, called " burnettizing," patented in 1838, is of- ten used. This consists in injecting chloride of zinc solution into the timber after the pores have been exhausted of air. The process was extensively employed in 1850 at Lowell, Mass., for the locks on the Merrimack river. Wood may be preserved by immersing it when thor- oughly dried in a solution of paraffine, heated under a pressure of six or eight atmospheres. The solvent, which may be coal naphtha, is then distilled off, to be used again. The See- ley process consists in subjecting the wood to a temperature between 212 and 300 F. while immersed in a bath of creosote for a sufficient time to expel the moisture. The pores are then filled only with steam, and the hot oil is replaced with cold, which creating a vacuum in the pores, they are filled with the oil. PRESHO, a S. county of Dakota, recently formed and not included in the census of 1870 ; area, about 1,600 sq. m. It is bounded N. E. PRESIDENT 825 by the Missouri, and is intersected by White river and Medicine creek. The surface con- sists of rolling prairies. PRESIDENT (Lat. praises), an officer appoint- ed or elected to preside over a tribunal, a com- pany, an assembly, or a republic. The chief executive officer of the United States bears this title, and the second executive officer, the vice president, is by virtue of his office the presi- dent of the senate, and succeeds to the office of president of the United States on the death or disability of the regular incumbent during his term. The chief executives of Mexico and the republics of Central and South America, as well as of Switzerland, are also termed presidents, and Marshal MacMahon governs under the same title in France. The president of the United States holds his office for the term of four years, beginning on the 4th day of March next succeeding the day of his election. He must be a native of the United States, at least 35 years old, and is chosen by electors who are themselves chosen by the people. Each state is entitled to a number of electors equal to its number of senators and representatives in congress, who meet at their respective state capitals on the first Wednes- day in December after their election, and trans- mit their votes to the president of the United States senate. The votes are canvassed by the two houses of congress in joint convention, and the result declared, on the second Wed- nesday of February following the meeting of the electors. Under the original provisions of the constitution the person having the sec- ond highest number of votes for president be- came vice president ; but the twelfth amend- ment (1804) provides for the separate election of those officers. The president's powers are thus fixed by the constitution of the United States, article II., section 2 : "The president shall be commander-in-chief of the army and navy of the United States, and of the militia of the several states when called into the actual service of the United States ; he may require the opinion in writing of the principal officer in each of the executive departments, upon any subject relating to the duties of their respec- tive offices, and he shall have power to grant reprieves and pardons for offences against the United States, except in cases of impeach- ment. He shall have power, by and with the consent of the senate, to make treaties, provi- ded two thirds of the senators present concur ; and he shall nominate, and, by and with the advice and consent of the senate, shall appoint ambassadors, other public ministers and con- suls, judges of the supreme court, and all other officers of the United States, whose appoint- ments are not herein otherwise provided for, and which shall be established by law; but the congress may by law vest the appointment of such inferior officers as they think proper in the president alone, in the courts of law, or in the heads of departments. The president shall have power to fill up all vacancies that
