\Scale\ (sk[=a]l), n. [AS. sc[=a]le; perhaps influenced by
the kindred Icel. sk[=a]l balance, dish, akin also to D.
schaal a scale, bowl, shell, G. schale, OHG. sc[=a]la, Dan.
skaal drinking cup, bowl, dish, and perh. to E. scale of a
fish. Cf. {Scale} of a fish, {Skull} the brain case.]
1. The dish of a balance; hence, the balance itself; an
   instrument or machine for weighing; as, to turn the scale;
   -- chiefly used in the plural when applied to the whole
   instrument or apparatus for weighing. Also used
   figuratively.
         Long time in even scale The battle hung. --Milton.
         The scales are turned; her kindness weighs no more
         Now than my vows.                     --Waller.
2. pl. (Astron.) The sign or constellation Libra.
{Platform scale}. See under {Platform}.

\Scale\, v. t. [imp. & p. p. {Scaled}; p. pr. & vb. n.
{Scaling}.]
To weigh or measure according to a scale; to measure; also,
to grade or vary according to a scale or system.
      Scaling his present bearing with his past. --Shak.
{To} {scale, or scale down}, {a debt, wages, etc.}, to reduce
   a debt, etc., according to a fixed ratio or scale. [U.S.]

\Scale\, n. [Cf. AS. scealu, scalu, a shell, parings; akin
to D. schaal, G. schale, OHG. scala, Dan. & Sw. skal a shell,
Dan. ski[ae]l a fish scale, Goth. skalja tile, and E. shale,
shell, and perhaps also to scale of a balance; but perhaps
rather fr. OF. escale, escaile, F. ['e]caille scale of a
fish, and ['e]cale shell of beans, pease, eggs, nuts, of
German origin, and akin to Goth. skalja, G. schale. See
{Shale}.]
1. (Anat.) One of the small, thin, membranous, bony or horny
   pieces which form the covering of many fishes and
   reptiles, and some mammals, belonging to the dermal part
   of the skeleton, or dermoskeleton. See {Cycloid},
   {Ctenoid}, and {Ganoid}.
         Fish that, with their fins and shining scales, Glide
         under the green wave.                 --Milton.
2. Hence, any layer or leaf of metal or other material,
   resembling in size and thinness the scale of a fish; as, a
   scale of iron, of bone, etc.
3. (Zo["o]l.) One of the small scalelike structures covering
   parts of some invertebrates, as those on the wings of
   Lepidoptera and on the body of Thysanura; the elytra of
   certain annelids. See {Lepidoptera}.
4. (Zo["o]l.) A scale insect. (See below.)
5. (Bot.) A small appendage like a rudimentary leaf,
   resembling the scales of a fish in form, and often in
   arrangement; as, the scale of a bud, of a pine cone, and
   the like. The name is also given to the chaff on the stems
   of ferns.
6. The thin metallic side plate of the handle of a
   pocketknife. See Illust. of {Pocketknife}.
7. An incrustation deposit on the inside of a vessel in which
   water is heated, as a steam boiler.
8. (Metal.) The thin oxide which forms on the surface of iron
   forgings. It consists essentially of the magnetic oxide,
   {Fe3O4}. Also, a similar coating upon other metals.
{Covering scale} (Zo["o]l.), a hydrophyllium.
{Ganoid scale}. (Zo["o]l.) See under {Ganoid}.
{Scale armor} (Mil.), armor made of small metallic scales
   overlapping, and fastened upon leather or cloth.
{Scale beetle} (Zo["o]l.), the tiger beetle.
{Scale carp} (Zo["o]l.), a carp having normal scales.
{Scale insect} (Zo["o]l.), any one of numerous species of
   small hemipterous insects belonging to the family
   {Coccid[ae]}, in which the females, when adult, become
   more or less scalelike in form. They are found upon the
   leaves and twigs of various trees and shrubs, and often do
   great damage to fruit trees. See {Orange scale},under
   {Orange}.
{Scale moss} (Bot.), any leafy-stemmed moss of the order
   {Hepatic[ae]}; -- so called from the small imbricated
   scalelike leaves of most of the species. See {Hepatica},
   2, and {Jungermannia}.

\Scale\, v. t.
1. To strip or clear of scale or scales; as, to scale a fish;
   to scale the inside of a boiler.
2. To take off in thin layers or scales, as tartar from the
   teeth; to pare off, as a surface. ``If all the mountains
   were scaled, and the earth made even.'' --T. Burnet.
3. To scatter; to spread. [Scot. & Prov. Eng.]
4. (Gun.) To clean, as the inside of a cannon, by the
   explosion of a small quantity of powder. --Totten.

\Scale\, v. i.
1. To separate and come off in thin layers or lamin[ae]; as,
   some sandstone scales by exposure.
         Those that cast their shell are the lobster and
         crab; the old skins are found, but the old shells
         never; so it is likely that they scale off. --Bacon.
2. To separate; to scatter. [Scot. & Prov. Eng.]

\Scale\, n. [L. scalae, pl., scala staircase, ladder; akin
to scandere to climb. See {Scan}; cf. {Escalade}.]
1. A ladder; a series of steps; a means of ascending. [Obs.]
2. Hence, anything graduated, especially when employed as a
   measure or rule, or marked by lines at regular intervals.
   Specifically:
   (a) A mathematical instrument, consisting of a slip of
       wood, ivory, or metal, with one or more sets of spaces
       graduated and numbered on its surface, for measuring
       or laying off distances, etc., as in drawing,
       plotting, and the like. See {Gunter's scale}.
   (b) A series of spaces marked by lines, and representing
       proportionately larger distances; as, a scale of
       miles, yards, feet, etc., for a map or plan.
   (c) A basis for a numeral system; as, the decimal scale;
       the binary scale, etc.
   (d) (Mus.) The graduated series of all the tones,
       ascending or descending, from the keynote to its
       octave; -- called also the {gamut}. It may be repeated
       through any number of octaves. See {Chromatic scale},
       {Diatonic scale}, {Major scale}, and {Minor scale},
       under {Chromatic}, {Diatonic}, {Major}, and {Minor}.
3. Gradation; succession of ascending and descending steps
   and degrees; progressive series; scheme of comparative
   rank or order; as, a scale of being.
         There is a certain scale of duties . . . which for
         want of studying in right order, all the world is in
         confusion.                            --Milton.
4. Relative dimensions, without difference in proportion of
   parts; size or degree of the parts or components in any
   complex thing, compared with other like things;
   especially, the relative proportion of the linear
   dimensions of the parts of a drawing, map, model, etc., to
   the dimensions of the corresponding parts of the object
   that is represented; as, a map on a scale of an inch to a
   mile.
{Scale of chords}, a graduated scale on which are given the
   lengths of the chords of arcs from 0[deg] to 90[deg] in a
   circle of given radius, -- used in measuring given angles
   and in plotting angles of given numbers of degrees.

\Scale\, v. t. [Cf. It. scalare, fr. L. scalae, scala. See
{Scale} a ladder.]
To climb by a ladder, or as if by a ladder; to ascend by
steps or by climbing; to clamber up; as, to scale the wall of
a fort.
      Oft have I scaled the craggy oak.        --Spenser.

\Scale\, v. i.
To lead up by steps; to ascend. [Obs.]
      Satan from hence, now on the lower stair, That scaled
      by steps of gold to heaven-gate, Looks down with
      wonder.                                  --Milton.