One of the most interesting examples of the varied technical application of a common term is that afforded by the use of the word °damper.° It is familiarly known as a plate, valve, cover or other suitable contrivance for regulating the amount of draught in the flues of a furnace or boiler. As a specific mechanical term it is applied to the °dash-pot° or small cylinder which forms a portion of the engines of the Corliss type, in which they act as a °buffer-case° and prevent the too sudden closing of the steam and exhaust valves. As an electrical term it is applied to a metallic cylinder which is placed in such a manner that it nearly or entirely encompasses the iron core of an induction coil for the purpose of effecting a variation in the intensity of the current pro duced in the secondary battery. As a term employed in musical construction and operation it is applied to the strip of felt or other soft material employed in a piano-forte for the pur pose of modulating the vibration of the strings.
A more varied technical application obtains in the case of the common word °pitch.° As used in connection with mechanical work it re fers to the distance between the centres of two adjacent teeth on a gear-wheel, to the distances between bolts, rivets and boiler stays or sim ilar* parts arranged equidistantly. Also to the
inclination or rake of the teeth of saws, to the angle at which a plane-iron is set on its stock and to the height or angle of a roof-truss. As an electrical term it refers to the successive corresponding conductors on the armature of a dynamo and the number of coils advanced in making end-connections between the coils of an armature winding divided into segments. It is also applied to designate the frequency of a tone vibration produced electrically. As a musical term it refers to a succession of tone vibrations.
The character of a technical term or the class of work to which it belongs is usually very clearly indicated by the textual matter on any particular subject, but in the case of me chanical and electrical terms when the distinc tion is not obvious, the special character of a term may be ascertained only by the nature of the power generated, controlled or applied.
For further information see articles un der the titles AERONAUTICAL NOMENCLATURE; BOILER SHOP TERMS; FOUNDRY AND FORGE SHOP TERMS; ENGINEERING TERMS; ELECTRICAL TERMS; LOCOMOTIVE, PRINCIPAL PARTS OF; TOOLS; VALVE AND VALVE TERMS, and WORK