sun 
familiar elements whose vapors thus impress their signa- 
ture upon the sunlight. According to the recent investi- 
gations of Rowland (not yet entirely completed), thirty-six 
of the chemical elements are already identified in the 
solar atmosphere, all of them metals, hydrogen excepted. 
Among them barium, calcium, carbon, chromium, cobalt, 
hydrogen, iron, magnesium, manganese, nickel, silicon, 
sodium, titanium, and vanadium are either specially con- 
spicuous or theoretically important. The fact that some 
of the most abundant and important of the terrestrial ele- 
ments fail to show themselves is, of course, striking, and 
probably significant. Chlorin, oxygen (probably), nitrogen, 
phosphorus, and sulphur are none of them apparent ; it 
would, however, be illogical and unsafe to infer from their 
failure to manifest themselves that they are necessarily 
absent, A difference of opinion prevails as to the precise 
region of the solar atmosphere in which Fraunhofer s lines 
originate. Some hold that the absorption which produces 
them takes place almost entirely in a comparatively thin 
stratum known as the reversing-layer, just above the sur- 
face of the photosphere. Lockyer holds, on the other 
hand, that many of them originate at a high elevation, 
and even above the chromosphere. Photometric observa- 
tions show that the brilliance of the solar surface far ex- 
ceeds that of any artificial light : it is about 150 times as 
great as that of the lime-cylinder of the calcium-light, and 
from two to four times as great as that of the " crater " of 
the electric arc. It is to be noted that the brightness of 
the sun's disk faUs off greatly near the edge, owing to the 
general absorption by the solar atmosphere. The solar 
constant is defined as the quantity of heat (in calories) 
received in a unit of time by an area of a square meter 
perpendicularly exposed to the sun's rays at the upper 
surface of the earth's atmosphere, when the earth is at 
its mean distance from the sun. This quantity can be 
determined, with some approach to accuracy (say within 
10 or 15 per cent.), by observations with pyrheliometers 
and actinometers. The earliest determinations (by J. 
Herschel and Pouillet, in 1838) gave about 19 calories a 
minute; later and more elaborate observations give larger 
results. Langley's observations make it very probable 
that its value is not under 30. Assuming it, however, 
as 25, it appears that the amount of energy incident 
upon the earth's atmosphere in the sun's rays is nearly 
2J continuous horse-power per square meter when the 
sun is vertical ; at the sea-level this is reduced about one 
third by the atmospheric absorption. The total amount 
of energy radiated by the sun's surface defies conception ; 
it is fully 100,000 continuous horse-power or more than 
1,100,000 calories a minute for every square meter, and 
according to Ericsson more than 400 times as great as that 
radiated by a surface of molten iron. It would melt in one 
minute a shell of ice 50 feet thick incasing the photosphere : 
to supply an equal amount by combustion would require the 
hourly burning of a layer of the best anthracite more than 
20 feet thick more than a ton for every square foot of sur- 
face. As to the temperature of the sun, our knowledge is 
comparatively vague. We have no means of determining 
with accuracy from our present laboratory data the tem- 
perature the photosphere must have in order to enable it 
to emit heat at the known rate. Various (and high) au- 
thorities set it all the way from about 2,600" C. to several 
millions of degrees. Experiments with burning-glasses, 
however, and observations upon the penetrating power 
of the solar rays, demonstrate that the temperature of the 
photosphere is certainly higher than that of any known 
terrestrial source, even the electric arc itself. The only 
theory yet proposed concerning the maintenance of the 
sun's heat which meets the case at all is that of Helm- 
holtz, who finds the explanation in a slow contraction of 
the solar globe. A yearly shrinkage of about 260 feet (or 
300 feet, if we accept Langley's value of the solar constant) 
in the sun's diameter would make good the whole annual 
expenditure of radiant energy, and maintain the tempera- 
ture unchanged. If this is the true explanation, it follows, 
of course, that in time probably in about eight or ten 
millions of years the solar heat will begin to wane, and 
will at last be exhausted. It should be noted also that 
certain other causes such, for instance, as the fall of me- 
teors on the sun contribute something to itsheat-supply; 
but all of them combined will account for not more than 
a small percentage of the whole. The view now generally 
accepted of the constitution of the sun accords with this 
theory of the solar heat. The sun is believed to be, in 
the main, a mass of intensely heated gas and vapor, 
powerfully compressed by its own gravity. The central 
part is entirely gaseous, because its temperature, being 
from physical necessity higher than that of the inclosing 
photosphere, is far above the so-called "critical point" 
for every known element ; no solidification, no liquefac- 
tion even, can therefore occur in the solar depths. But 
near the outer surface radiation to space is nearly free 
the temperature is lowered to a point below the "criti- 
cal point " of certain substances, and under the powerful 
pressure due to solar gravity condensation of the vapors 
begins, and thus a sheet of incandescent cloud is formed 
which constitutes the photosphere. The chromosphere 
consists of the pennanent gases and uncondensed vapors 
which overlie the cloud-sheet, while the corona still re- 
mains in great degree a mystery, as regards both the sub- 
stances which compose it and the forces which produce 
and arrange its streamers. See also cut under sun-spot. 
To fynde the degree in which the sonne is day by day 
alter hir cours abowte. Chaucer, Astrolabe, ii. 1. 
I'll say this for him, 
There fights no braver soldier under sun, gentlemen. 
fVetcher, Humorous Lieutenant, i. 1. 
To him that sitting on a hill 
Sees the midsummer, midnight, Norway sun 
Set into sunrise. Tennyson, Princess, iv. 
Without solar fire we could have no atmospheric vapour 
without vapour no clouds, without clouds no snow and 
without snow no glaciers. Curious then as the conclusion 
may be, the cold ice of the Alps has its origin in the heat 
of the tun. Tyndall, Forms of Water, p. 7. 
2. The sunshine; a sunny place; a place where 
the beams of the sun fall : as, to stand in the 
sun (that is, to stand where the direct rays of 
the sun fall). 3. Anything eminently splendid 
6058 
or luminous ; that which is the chief source of 
light, honor, glory, or prosperity. 
The sun of Home is set ! Shak., J. C., v. 8. 63. 
I will never consent to put out the sun of sovereignty to 
posterity. Eikon Ba&ilike. 
4. The luminary or orb which constitutes the 
center of any system of worlds: as, the fixed 
stars may be suns in their respective systems. 
5. A revolution of the earth round the sun ; 
a year. . 
Vile it were 
For some three suns to store and hoard myself. 
Tennyson, Ulysses. 
6. The rising of the sun ; sunrise ; day. 
Your vows are frosts, 
Fast for a night and with the next gun gone. 
Beau, and Ft., Philaster, iii. 2. 
7. In her., a bearing representing the sun, usu- 
ally surrounded by rays. It is common to nil the 
disk with the features of a human face. When anything 
else is represented there, it is mentioned in the blazon : 
as, the sun, etc., charged in the center with an eye. See 
sun in splendor, below. 
8. In electric lighting, a group of incandescent 
lamps arranged concentrically under a reflec- 
tor at, near, or in the ceiling of a room or audi- 
torium. 
The interior of the copious reflectors contains a cluster 
of electrical lamps. In addition to these there are 12 
nuns in the ceiling. Elect. Rev. (Amer.), XVII. 235. 
Against the sun. See against. Blue sun, a colored 
appearance of the sun resulting from a peculiar selec- 
tive absorption of its rays by foreign substances in the 
atmosphere. The phenomenon has been observed es- 
pecially after great volcanic eruptions, notably after the 
Krakatoa eruption of 1883, when large quantities of foreign 
matter were projected into the atmosphere. The precise 
nature of the particles or gases producing the absorption 
is not known. Collar of suns and roses, a collar granted 
by the English sovereigns of the house of York as an hon- 
orary distinction in rivalry of the Lancaster collar of 88. 
It is a broad band decorated with, alternately, the white 
rose of York and the sun adopted by Edward IV. as his 
personal cognizance. Fixed sun, a kind of pyrotechnics 
consisting of a certain number of jets of fire arranged 
circularly like the spokes of a wheel. From sun to sun, 
from sunrise to sunset. 
sunbonnet 
sun-animalcule (sun'an-i-mal"kul), . A he- 
liozoan, or radiant filose protozoan of the group 
Heliozoa, such as Actinoplinjs sol, to which the 
name originally applied. These little bodies are 
amrebiform, but of comparatively persistent spherical 
fiaure, from all parts of the surface of which radiate flue 
filamentous pseudopodia with little tendency to move, or 
Man's work 's/rowi sun to sun, 
Woman's work 's never done. 
Old rime. 
Green sun. Same as blue sun. Line Of the sun, in pal- 
mistry. See line!!, Mean sun. See mean*. Midnight 
sun, the sun as visible at midnight in arctic regions. 
Mock sun. See parhelion. Nadir of the sun. See 
nadir. Order Of the Rising Sun, an order of the em- 
pire of Japan, founded in 1876. Order of the Sun and 
Lion, a Persian order, founded in 1808 by the shah, for 
military and civil service and for conferring honor on 
strangers, as ambassadors at the court of Persia. The 
badge is a species of star, of which the center is a medal- 
lion, upon which is represented the rising sun, and from 
which radiate six blades or bars with rounded points. 
The ribbon is red. Revolving sun, a pyrotechnic de- 
vice consisting of a wheel around the periphery of which 
are fixed rockets of various styles. K H. Knight. Sun- 
and-planet wheels, an ingenious contrivance adopted 
by Watt in the early history of the steam-engine, for con- 
verting the reciprocating mo- 
tion of the beam into a rotatory 
motion. See cut under planet- 
wheel. Sun before or after 
Clock, the amount by which, 
at certain times of the year, an 
accurately adjusted sun-dial is 
faster or slower than a correct 
mean solar clock. Sun in 
splendor, or In his splen- 
dor, in her., the sun surround- 
ed by rays which are generally 
as long as the diameter of the 
disk or even longer, and alter- 
Sun in Splendor. nately straight and waved. 
Sun lamp. See tempi. Sun 
of righteousness, in Scrip., one of the titles of Christ. 
The rising of the sun. See rising. To have the sun 
In one's eyes, to be intoxicated. Dickens, Old Curiosity 
Shop, ii. [Slang.] To shoot the sun. 8eeAoot. To 
take the sun (naut.), to ascertain the latitude by obser- 
vation of the sun. Under the sun, in the world; on 
earth : a proverbial expression. 
There is no new thing under the mm. 
Eccl. i. 9. 
With the sun, in the direction of the apparent move- 
ment of the sun. 
Sun 1 (sun), v.; pret. and pp. sunned, ppr. sun- 
ning. [= D. gonnen = LG. sunnen = G. sonnen; 
from the noun.] I. trans. To expose to the 
sun's rays ; warm or dry in the sunshine ; inso- 
late: as, to sun cloth. 
To tun thyself in open air. 
Dryden, tr. of Persius's Satires, iv. 37. 
Spring parts the clouds with softest airs, 
That she may sun thee. 
Wordsworth, To the Daisy. 
II. intrans. To become warm or dry in the 
sunshine. 
The fields breathe sweet, the daisies kiss our feet, 
Young lovers meet, old wives &-sunning sit. 
If ash, Spring. 
sun- 1 , n. bee sunn. 
sun-angel (sun'an'jel), n. A humming-bird of 
the genus Heliangelus. 
Sun-animalcule (Actinep/irys sol), magnified 250 times. 
change in form, except when the animalcule is feeding. 
The protoplasm is vacuolated, and nucleated with one 
or several nuclei ; a kind of test or shell may be devel- 
oped or not. Some are stalked forms. They mostly in- 
habit fresh water, and are very attractive microscopic ob- 
jects. There are various generic forms besides Actino- 
phrys, as Actinosphterium and Clathrulina. See these 
technical names, Heliozoa, and cut under Clathrulina. 
sun-bath (sun'bath), n. Exposure of the naked 
body to the direct rays of the sun, especially as 
a therapeutic measure. 
sunbeam (sun'bem), n. [Early mod. E. also 
sunnebeam; < ME. sonnebeme, < AS. smmebedm, 
< sunne, sun, + bedm, beam: see sun 1 and 
beam.] A ray of the sun. 
Ther vnder sate a creature 
As bright as any sonne beme. 
Political Poems, etc. (ed. Furnivall), p. 102. 
The gay motes that people the stmbeams. 
Miltoti, II Penseroso, 1. 8. 
sun-bear (sun'bar), n. 1. A bear of the genus 
Helarctos; the bruang, or Malay bear, H. ma- 
layanus, of small size and slender form, with a 
close black coat and a white mark on the throat. 
See cut under bruang. 2. The Tibetan bear, 
Ursus thibetanus. [A misnomer.] 
sun-beat, sun-beaten (sun'bet, sun'be'tn), a. 
Smitten by the rays of the sun. [Rare.] 
And wearies fruitful Nilus to convey 
His sun-beat waters by so long a way. 
Dryden, tr. of Juvenal's Satires, x. 289. 
sun-beetle (sun'be"tl), n. One of several me- 
tallic beetles of the genera Amaru, Pcecilus, 
etc.; anycetonian: so called from their run- 
ning about in the sunshine. Westwood. 
sunbird (sun'berd), n. A common name of 
various birds, (a) A general or indiscriminate name 
of cinnyrimorphic birds, 
of the genera Nectarinia, 
Cinnyris,Dicaum,&nd re- 
lated forms, of more than 
one family. See also cut 
under JHcseum. (b) An 
exact book-name of the 
honey-suckers, nectar- 
birds, or Nectariniidte, 
mostly of glittering me- 
tallic iridescence, as Cin- 
nyris superba, of western 
Africa, a characteristic 
example. See cut under 
Jirepanis. (c) The sun- 
bittern, (d) A sun-grebe. See cuts under Heliomis and 
Podica. (e) An unidentified bird, probably any bird asso- 
ciated with sun-worship or similar religious rites. See the 
quotation, and compare wakon-bird. 
When at midday the sunlight poured down upon the 
altar, . . . the ttun-birdit, the Tonatzuli, were let fly sun- 
wards as messengers. E. B. Tylor, Prim. Culture, II. 289. 
sun-bittern (sun'bif'ern), n. A South Ameri- 
can bird, JEurypyga Delias: so called from the 
brilliant ocellated plumage. Also named i>i'- 
wek-bittern, for the same reason. See cut under 
Ewrupyga. 
sun-blink (sun'blingk), n. A flash or glimpse 
of sunshine. Scott. [Scotch.] 
sunbonnet (sun'bon"et), H. A light bonnet pro- 
jecting in front so as to protect the face, and 
having a flounce or cape to protect the neck. 
The pale and washed-out female who glares with . . . 
stolidity from the recesses of her telescopic gun-bonnet. 
Fortnightly See., X. S., XXXIX. 7G. 
Sunbird (Cinnyrts sitperba). 
