REALISM............................................................CONVENTIONALISM.
COMPLETE REALISM, in which all parts are represented, inproper colors, and perfect gradation, with correct light andshade (see § 10).FIRST DEGREE OF CONVENTIONALISM, in which all parts arerepresented: (a) By a reduced number of Pigments, the otherqualities remaining; (b) By reduction in gradation andshading to Flat-tints of several pigments (see § 15).SECOND DEGREE OF CONVENTIONALISM, in which all parts arerepresented: (c) By a reduction to Monochrome of color, withGradation (only) remaining; (d) By reduction to Monochromeof White and Black, with Gradation (only) remaining (see §16).THIRD DEGREE OF CONVENTIONALISM, in which all parts arerepresented: (e) By reduction to a Flat-tint of one pigmenton a ground of another; (f) By reduction to a Flat-tint ofWhite on Black, or vice versa (see § 17).ULTIMATE CONVENTIONALISM, in which all parts arerepresented; (g) By reduction to Outline of severalpigments; (h) Reduction to Outline of one pigment (see §18).

Inasmuch as Realism ceases so soon as any reduction in the three qualities (of color, gradation, and shadow) is introduced; and the treatment becomes more Conventional in each method after the first—these are classified under the heading of CONVENTIONALISM.

[There is an analogous scale of reduction in Form, from the Complete-relief of an isolated Statue to the Flatness of a Floor-plate; but this does not belong to the present subject.]

[1]

Lectures before the Society of Arts, London, 1891.

THE CYCLOSTAT.

The various processes commonly employed for the observation of bodies in motion (intermittent light or vision) greatly fatigue the observer, and, as a general thing, give only images, that are difficult to examine. We are going to show how Prof. Marc Thury, upon making researches in a new direction, has succeeded in constructing an apparatus that permits of the continuous observation of a body having a rapid rotary motion. The principle of the method is of extreme simplicity.