Militate. In determining a question, to have weight, or to influence a decision. Mobility. Being freely movable; capable of quick change. Modifieation. A change; making a difference. Monitor. Advising or reproving. Advising or approving by way of caution. Monstrosities. Anything which is huge, or distorted, or wrong in structure. Monorail. A railway with a single track, designed to be used by a bicycle form of carriage, with two wheels, fore and aft of each other, and depending for its stability upon gyroscopes, mounted on the carriage. Momentum. That which makes a moving body difficult to stop. It is the weight of a moving body, multiplied by its speed. Monoplane. The literal meaning is one plane. As monoplane machines are all provided with a fore and aft body, and each has a wing or plane projecting out from each side of this body, it is obvious that it has two planes instead of one. The term, however, has reference to the fact that it has only one supporting surface on the same plane. Biplanes have two supporting surfaces, one above the other. Multiplicity. Frequently confounded with plurality. The latter means more than one, whereas multiplicity has reference to a great number, or to a great variety. Muscular. Being strong; well developed. Negative. The opposite of positive; not decisive. Neutralize. From the word neuter, which means neither, hence the term may be defined as one which is not a part of either, or does not take up with either side. Normal Pressure. Normal means the natural or usual, and when applied to air it would have reference to the condition of the atmosphere at that particular place. If the pressure could change from its usual condition, it would be an abnormal pressure. Notoriously. Generally known, but not favorably so; the subject of general remark; or unfavorably known. Obscurity. Not well known; in the background; without clear vision; hidden from view. Obliquely. That which differs from a right angle; neither obtuse nor acute; deviating from a line by any angle except a right angle. Obvious. That which is readily observed and understood. Orthopter. That type of flying machine which depends on flapping wings to hold it in space, and to transport it, in imitation of the motion of the wings of birds in flying. Oscillate. Moving to and fro; the piston of a steam engine has an oscillating motion. Outline. Describing a marginal line on a drawing; setting forth the principal features of an argument, or the details of a story, or the like. Overlapping. One placed over the other. Parabolic. A form of curve somewhat similar to an ellipse. Pedestal. A standard or support; an upright to hold machinery. Pertinent. Appropriate; pertaining to the subject. Pectoral. The bone which forms the main rib or support at the forward edge of a bird's wing. Persistent. Keeping at it; determination to proceed.