MAN OF BLOOD AND IRON. MAN OF BLOOD AND IRON, The. A name given to Prince Bismarck, originating in a plirase used by himself in regard to tlie settle- ment of the diilerences of Prussia and Austria. MAN OF DECEMBER, The. Napoleon III., so called because of his coup d'etat of December 2, 1851. MAN OF DESTINY, The. A name given to Napoleon Bonaparte, who considered himself spe- ciall}' chosen and directed by fate. MAN OF LAW'S TALE, The. One of Chau- cer's Canlerhury Tuhs. It is the story of Con- stance, told in Gower's Coiifessio Amnntis, and taken from old French romances. Constance, daughter of the Emperor of Rome, married the vSultan of Syrie. who was killed at a feast. In a rudderless shi]) Constance reached Northumbria and wedded King Alia. Enemies place her and her son in the ship, and after many perils she is found by Alia at Eome. MAN OF MODE, The, or Sir Topling Flut- TEE. A comedv by George Etlierege, presented in 1070. MAN OF SIN. See Antichrist. MAN - OF - THE - EARTH. A weed. See Ipomcea. MAN-OF-WAR. An arnied naval vessel regularly commissioned by some acknowledged government and fitted for purposes of war. As such she possesses the privileges of war; her deck is, by a legal fiction, taken to be a portion of the soil of the nation whose flag she hoists; in time of war she is justified in attacking, sinking, burn- ing, or destroying the ships and goods of the foe, and, by the law of nations, she may stop and search the merchant vessels of neutral powers which s!ie suspects of carrying aid to her enemy. (See CoNTR.B.XD OF Wak; and Neutrality.) In case of being overpowered, the crew of a man- of-war are entitled to the ordinary mercy granted to vanquished combatants, lawfully fighting. Any vessel making war. but not belonging to an ac- knowledged government, is either a privateer ( see Marque, Letters of) or a pirate (see Piracy). See Cruiser; Ships, Armored; Shipbuilding; Navies; Ram; Mortar Vessel. MAN-OF-WAR, Portuguese. See Portu- guese JIan-of-Wak. MAN-OF-WAR BIRD, or HAWK (so called from its iircdatorv habits) . A frigate-bird (q.v.), but occasionally the term is applied to some other swift anil predaceous sea fowl, as a skua, MANOM'ETER (from Gk, «av<Sf, mnnos, thin, rare -{- filrpov, mctron, measure). An instrument for measuring the density or pressure of the air or any gas. A barometer (q.v.) is one form of manometer, as the pressure of the atmosphere is measured by the height of the column of mer- cury which it supports. The manometer in its simplest form would be a glass tube open at both ends and bent into the form of a U and contain- ing a sufficient quantity of some liquid to cover the bend and rise to a small height in each arm. The vessel containing the gas whose pressure is to be ascertained is connected with one arm of the tube, and if the gas is at the same pressure as the atmosphere the liquid will stand at the same level in both tubes. If the gas is at a greater pressure the liquid in the arm of the tube on which it acts will be at a lower level, and the pressure of the gas will be obtained by adding to the pressure of the atmosphere the weight of i MANOMETER. a column of the liquid whose height is equal to the dill'erence in level in the two tubes. When the pressure of the gas is considerably greater than that of the atmosphere we use mercury on account of its high specific gravity, and when the pressures are sufficient a tube with one arm closed can be em- ployed and the press- ure determined by measuring the extent to which the air is compressed. Now, ac- cording to Boyle's or Mariotte's law, a pressure exerted on the column of mer- cury sufficient to force the air into half the space it occupies at the normal atmos- pheric pi'essure, must become doubled, or 15 pounds to the square inch nmst be added. Again, to compress the air into halt the remaining space, .30 poimds, or double the pressure required for the reduction to the first half, must be added, making in all a pressure of four at- MANOMETER. mosphcres for the re- A, tor pressures greater than duction to one-fourth one atniospliere; B. for pies- the original volume, sures less than one atmos- It is evident, there- V^"""- fore, that a graduated scale, to exhibit the degrees of pressure, must have its spaces decrease from below upward. If the gas is considerably rarer than the air, as for example in the receiver of an air pump, we employ a shortened barometer consisting of a bent tube with one end closed but filled with mercurv, which BOURDON PRESSCKE GAUGE, WITH FACE REMOVED. is supported by the pressure of the atmosphere. In this case the .pressure is measured uy the dif- ference in level of the two columns, which would be zero were the vacuum perfect. These manometers are of course constructed in various forms, depending upon the use to which they are to be put, and the tubes and air cham- bers are variously constructed. The most common
