Hydro-carbons to Hydrostatic joint
Hydro-carbons. (Chern.) Those compounds that contain hydrogen and carbon only; paraffins, olefines, acetylenes, benzines, etc.
Hydro-chloric acid. (HCI) Occurs in nature as a constituent of volcanic gases. Commercially, the principal product of the action of sulphuric acid and salt. Used as a flux for soldering; also has wide use in industry.
Hydro-cyanic or pirussic acid. An intensely poisonous, colourless gas or liquid. Obtained by distilling a concentrated solution of potassium cyanide ~ith dilute sulphuric acid and absorption of the vapors in water.
Hydro-dynamics. That branch of mechanics which treats of the laws of motion and action of water and other liquids.
Hydro-electric. (Elec.) Relating to the production of electricity by water power.
Hydrofluoric acid. A volatile, colourless, corrosive liquid compound (HF) formed by decomposing metallic fluorides and sulphuric acid. It is used for etching on glass, in ceramics, in brewing, and in yeast.
Hydrofoil or hydrovane. (Aero.) Any surface designed to obtain reaction from the water through which it moves.
Hydrogen. (Chern.) Found free in nature in very small quantities. In combination it is one of the most abundant of the elements. When pu~e, it is a colourless, tasteless, odourless gas.
Hydrogenation. (Plast.) Chemcial process whereby hydrogen gas is introduced into a compound.
HydrogenbomhAsuperbombin which . hydrogen provides the basic force for the thermonuclear reaction.
Hydrolysis. (Plast.) Chemical decomposition of a substance involving the addition of water.
Hydromatic welding. A resistance welding process wherein each one of two or more electrodes in sequence goes through a complete
welding cycle under the control of a hydraulic-sequencing device synchronized with a weldingcurrent control device.
Hydro mecltanics. (Phys.)A branch of mechanics which considers the equilibrium and motion of fluids and of bodies in or surrounding them. Hydrostatics and. hydrodynamics are divisions of hydromechanics.
Hydrometer. An instrument for determining the specific gravity of liquids.
Hydrostatic brakes. (Auto.) A brake system, containing fluid, which is hermetically sealed. Pressure on the foot pedal distorts the fluid reservoir and pressure is distributed
equally to all four wheels. At each. wheel a brake fluid chamber expands outward, forcing six brake shoes against the brake drum.
Hydrostatic joint. (Plumb.) Used in large water mains, in which sheet lead is forced tightly into the bell
of a pipe by means qf the hydrostatic pressure of a liquid. .
Hydrostatics to Hysteresis
Hydrostatics. Treats of the equili.brium and pressure of fluids at rest. (Phys.) The science of pressure and equilibrium of fluI ids.
Hydrous. (Chem.) Containing water in chemical combination.
Hydroxyl. (Chem.) (OH) A characte-ristic part of bases consisting of one atom of hydrogen and one of oxygen..
Hygrometer. An instrument for measuring the amount of moisture in the atmosphere.
Hygroscopic. (Plast.) Property of absorbing moisture.
Hyperbola~ A conic section. The curve obtained by passing a plane. through a cone parallelel to its vertical axis.
Hyperbolic. (Math.) Of, pertaining to, oc.having the shape of a hyperbola.
Hyper-eutectoid. (Metal.) Steel containing less than the eutectoid percentage of carbon.
Hypocycloid. A curve formed by the path of a point on a circle which rolls on the interior of a base or
fundamental circle.. The curves of the flanks. of cycIoidal gear teeth are hypocyloids.
Hypoid. (Mach.) An abbreviation of hyperboloidal. The tenD is applied to a special type of spiral-bevel gear tooth.
Hypoid gears. (Auto. Mech.) A type of spiral-bevel gears which permit the location of the pinion above or below the center . of the gear w.ith which it meshes.
Hypoid gears are now largely used fot the rear axle drive in all passenger automobiles.
Hypotenuse. The diagonal which joins the sides of a right-angled triangle.
Hypotenuse o~long. (Print.) Refers to the ratio of page to width, approximately I Yz to I.
Hypothesis. An assumption as basis for investigation or reasoning.
Hypsometer. An apparatus for the calibration of thermometer at the steam point.
Hysteresis. (Elec.) A lagging of magnetic density behind the magnetizing force, causing a loss resulting in heat.
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