[a. Fr. amplitude, ad. L. amplitūdo, -inem, breadth, f. ampl-us: see AMPLE and -TUDE.] The quality of being ample.
1. Extension in space, extent, largeness; chiefly, width, breadth.
1599. Nashe, Lenten Stuffe (1871), 81. It cuts out an Island of some amplitude.
1671. Grew, Anat. Plants, I. i. (1682), 9. Growing to a three-four-five-fold amplitude above their primitive size.
1823. Lamb, Elia, Ser. I. xv. (1865), 121. An amplitude of form and stature, answering to her mind.
1833. Chalmers, Constit. Man (1835), I. v. 208. Throughout the amplitudes of savage and solitary nature.
2. Of things immaterial: Width, breadth, fullness; copiousness, abundance.
1605. Bacon, Adv. Learn., II. § 2 (1873), 76. All works are overcommen by amplitude of reward … and by the conjunction of labours.
1664. H. More, Myst. Iniq., I. viii. 248. The main Sea, the amplitude of that Jurisdiction to which they belong.
1794. Paley, Nat. Theol., xxvi. (1879), 412. It is in those things … that the amplitude of the Divine benignity is perceived.
1850. T. T. Lynch, Theoph. Trin., viii. 138. The blue of day shall image for us the amplitude of the divine charity.
1864. Sat. Rev., 31 Dec., 813/2. Motley … arrays all the facts before the reader in their original amplitude.
3. Of mental capacity: Breadth, wide range.
1575. Laneham, Lett. (1871), 48. Az for the Amplitude of his Lordship’s mynde.
c. 1652. J. Smith, Select Disc., IX. iii. (1821), 423. Religion … does work the soul into a true and divine amplitude.
1746. Hervey, Medit. & Contempl. (1818), 139. The amplitude of a generous heart.
1814. Cary, Dante, Par., X. 110. Endowed With sapience so profound … That with a ken of such wide amplitude No second hath arisen.
1828. Macaulay, Hallam, Ess., I. 52. His mind is … distinguished by the amplitude of its grasp.
4. Excellence, dignity, grandeur, splendor.
1549. Compl. Scotl., 2. Ȝour honorabil amplitude of verteouse dignite incressis daly.
1655. Fuller, Ch. Hist., I. 10. This was conceived to conduce to the state and amplitude of their Empire.
1660. R. Coke, Power & Subj., 180. To the greater amplitude and glory of God.
1834. Foster, Pop. Ignor., 456. Religion, believed and felt, is the amplitude of our moral and intellectual nature.
5. Astr. The space by which a celestial body rises wide of due east, or sets wide of due west; its angular distance at rising or setting from the eastern or western point of the horizon.
When reckoned from the eastern and western points as shown by the compass, the Amplitude is Magnetic.
1627. Smith, Seaman’s Gram., xv. 83. To obserue the … Amplitude.
1658. Phillips, s.v., The Amplitude of the Sun and Stars is an Arch of the Horizon, comprehended between the true East and West Point of it, and the Center of the Sun, Moon, or any Star, at its Rising or Setting.
1697. Dampier, Voy. (1729), I. 531. Taking the Suns Amplitude mornings and evenings.
1779. Forrest, Voy. N. Guinea, 107. To day found the variation of the compass, by the medium of several amplitudes taken ashore.
1834. U. K. S., Nat. Phil., III. xiii. 256/2. Amplitude … differs from the azimuth merely in being counted from the east and west points, instead of from north and south.
6. Extent of motion in space.
1880. Darwin, Movem. Plants, 3. The great sweeps made by the stems of twining plants … result from a mere increase in the amplitude of the ordinary movement of circumnutation.
Hence a. in Gunnery, The range of a projectile.
1727–51. Chambers, Cycl., Amplitude of the range of a projectile denotes the horizontal line subtending the path in which it moved.
b. esp. in Physics. Amplitude of a vibration: the distance that an individual particle moves from side to side in performing a complete vibration.
1837. Brewster, Magnetism, 222. The diurnal oscillations have a small amplitude between the tropics.
1869. Tyndall, Light, § 220. The intensity of the light depends on the distance to which the ether particles move to and fro. This distance is called the amplitude of the vibration. The intensity of light is proportional to the square of the amplitude.
1876. Blaserna, Sound, iii. 48. The loudness of a sound is represented by the amplitude of the vibrations causing it.
