GRADUATION

, is used for the act of Graduating, or dividing any thing into degrees.

For an account of the various methods of Graduating mathematical and astronomical instruments, by straight and circular diagonals, and by concentric arcs, &c; see Plain Scale, Nonius, and Vernier. And for an account of Mr. Bird's improved method of dividing astronomical instruments, see Mural Arch.

Mr. Ramsden, an ingenious mathematical instrumentmaker of London, has lately published, by encouragement of the commissioners of longitude, an explanation| and description of an engine contrived by him for dividing mathematical instruments, accompanied with proper drawings; in consideration of which, the said commissioners have granted to him the sum of 615l. See his book, 4to, 1777.

On the subject of dividing a foot into many thousand parts, for mathematical purposes, see Philos. Trans. vol. 2, p. 457, 459, 541, or Abr. vol. 1, pa. 218, 220, &c. And for an account of various other methods and Graduations, see a paper of Mr. Smeaton's in the Philos. Trans. vol. 76, for the year 1786, p. 1; being “Observations on the Graduation of astronomical instruments; with an explanation of the method invented by the late Mr. Henry Hindley, of York, clockmaker, to divide circles into any given number of parts.”