Common Measurements
Diameter of a circle × 3.1416 = Circumference.
Radius of a circle × 6.283185 = Circumference.
Square of the radius of a circle × 3.1416 = Area.
Square of the diameter of a circle ×.7854 = Area.
Square of the circumference of a circle ×.07958 = Area.
Half the circumference of a circle × half its diameter = Area.
Circumference of a circle ×.159155 = Radius.
Square root of the area of a circle ×.56419 = Radius.
Circumference of a circle × 31831 = Diameter.
Square root of the area of a circle × 1.12839 = Diameter.
Diameter of a circle ×.86 = Side of inscribed equilateral triangle.
Diameter of a circle ×.7071 = Side of an inscribed square.
Circumference of a circle ×.226 = Side of an inscribed square.
Circumference of a circle ×.282 = Side of square of equal area.
Diameter of a circle ×.8862 = Side of a square of equal area.
Base of a triangle × one-half the altitude = Area.
The product of both diameters ×.7854 = Area of an ellipse.
Surface of a sphere × one-sixth of its diameter = Solidity.
Circumference of a sphere × its diameter = Surface.
Square of the circumference of a sphere ×.3183 = Surface.
Square root of the surface of a sphere × 1.772454 = Circumference.
Square of one of its sides × 6 = Surface of a cube.
Area of the base of a square, round or triangular pyramid, or of a cone, × one-third of its altitude = Solidity.
Area of square ×.7854 = Area of largest circle within it.
Area of circle ×.625 = Area of largest square within it.
Spheres.—Square of circumference ×.3183 = Surface of sphere.
Square of diameter × 3.1416 = Surface of sphere.
Square root of surface ×.5642 = Diameter of sphere.
Cube of diameter ×.5236 = Solidity of sphere.
Cube of circumference ×.0169 = Solidity of sphere.
Cube root of solidity × 1.2407 = Diameter of sphere.
Diameter of sphere ×.5774 = Side of inscribed cube.
Square root of solidity ×.2821 = Radius.
Square root of solidity × 1.7725 = Circumference.
Cube of radius × 4.1888 = Solidity.
Cube root of solidity ×.6204 = Radius.
Cube root of solidity × 3.8978 = Circumference.
Communism and Socialism.—Communism is a doctrine which would abolish individual rights, including the ownership of property. It began in England and France, but has never made any great progress. Socialism is allied to Communism, but is a milder form. It does not suggest the abolition of individual rights, but to make all rights subordinate to the good of the people. An acceptable definition of either has never been presented, and members of both parties differ materially. Socialism, however, has grown very rapidly, and the Socialistic Party in the United States is frequently successful. Some of our ablest scholars and investigators believe that Socialism will become prevalent, and that in it is vested many of the solutions to our economic problems.