of water in an impervious basin.

AUTHORITIES.--For _Dew_, see the two essays by Dr Charles Wells
(London, 1818), also "An Essay on Dew," edited by Casella (London,
1866), Longmans', with additions by Strachan; Melloni, _Pogg. Ann._
lxxi. pp. 416, 424 and lxxiii. p. 467; Jamin, "Complements a la
theorie de la rosee," _Journal de physique_, viii. p. 41; J. Aitken,
on "Dew," _Trans. Roy. Soc. of Edinburgh_, xxxiii., part i. 2, and
"Nature," vol. xxxiii. p. 256; C. Tomlinson, "Remarks on a new Theory
of Dew," _Phil. Mag._ (1886), 5th series, vol. 21, p. 483 and vol. 22,
p. 270; Russell, _Nature_, vol 47, p. 210; also _Met. Zeit._ (1893),
p. 390; Homen, _Bodenphysikalische und meteorologische Beobachtungen_
(Berlin, 1894), iii.; _Taubildung_, p. 88, &c.; Rubenson, "Die
Temperatur-und Feuchtigkeitsverhaeltnisse in den unteren Luftschichten
bei der Taubildung," _Met. Zeit._ xi. (1876), p. 65; H. E. Hamberg,
"Temperature et humidite de l'air a differentes hauteurs a Upsal,"
_Soc. R. des sciences d'Upsal_ (1876); review in _Met. Zeit._ xii.
(1877), p. 105.

For _Dew Ponds_, see Stephen Hales, _Statical Essays_, vol. i.,
experiment xix., pp. 52-57 (2nd ed., London, 1731); Gilbert White,
_Natural History and Antiquities of Selborne_, letter xxix. (London,
1789); Dr C. Wells, _An Essay on Dew_ (London, 1818, 1821 and 1866);
Rev. J. C. Clutterbuck, "Prize Essay on Water Supply," _Journ. Roy.
Agric. Soc._, 2nd series, vol. i. pp. 271-287 (1865); Field and
Symons, "Evaporation from the Surface of Water," _Brit. Assoc. Rep._
(1869), sect., pp. 25, 26; J. Lucas, "Hydrogeology: One of the
Developments of Modern Practical Geology," _Trans. Inst. Surveyors_,
vol. ix. pp. 153-232 (1877); H. P. Slade, "A Short Practical Treatise
on Dew Ponds" (London, 1877); Clement Reid, "The Natural History of
Isolated Ponds," _Trans. Norfolk and Norwich Naturalists' Society_,
vol. v. pp. 272-286 (1892); Professor G. S. Brady, _On the Nature and
Origin of Freshwater Faunas_ (1899); Professor L. C. Miall, "Dew
Ponds," _Reports of the British Association_ (Bradford Meeting, 1900),
pp. 579-585; A. J. and G. Hubbard, "Neolithic Dewponds and
Cattle-Ways" (London, 1904, 1907). (W. N. S.)

DEWAN or DIWAN, an Oriental term for finance minister. The word is
derived from the Arabian _diwan_, and is commonly used in India to
denote a minister of the Mogul government, or in