SPEYER. 441 SPHERE. SPEYER, spl'er, or SPEIER (in Eng. often Spire). The capital of the Palatinate, Bavaria, sitviated at the confluence of the Speyerbacli and the Rhine, 23 miles north of Karlsruhe (Jlap: Prussia, C 4). The chief feature is the magnifi- cent cathedral, a vast Romanesque edifice. Its construction was begun in 1030 by Conrad II., the founder of the Franconian dynasty of German emperors, and in its original form it was com- pleted in the reign of his grandson, Henry IV. It was long the burial place of the German em- perors. It sufl'ered in lOSn and 1794 from the vandalism of the French invaders, wlio spared nothing. The work of restoration was com- pleted in 1858. The interior is embellished with magnificent frescoes, statues, and reliefs by Schraudolph and other masters. Among the other architectural monuments of the city is a splendid gate of the thirteenth century. Speyer has a fine museum of antiquities. The manufac- tures include woolens, machinery, shoes, tobacco, vinegar, and sugar. Speyer, the Roman Augusta Nemetum (later Ivoviomagus), was created an episcopal see in 348. It was a favorite residence of the German emperors, and became a free Im- perial city in 1294. At the Diet of Speyer in 1529 the followers of Luther presented their pro- test, which gave them the appellation of Protest- ants. The city belonged to France from 1801 to 1814, when it passed to Bavaria. Population, in 1900, 20,911. SPEZIA,. spet'se-a. A city in the Province of Genoa, Italy, on the Gulf of Spezia, 5G miles by rail .southeast of Genoa (Map: Italy, D 3). The beautiful, scenery and mild climate have made it a favorite Avinter resort. The advantages of the Gulf as a naval station were pointed out by Napoleon I., and in 1861 the Italian Government made it the chief naval harbor of Italy. On the liills around the harbor there are strong fortifications. The ship-building yards are im- portant, some of the largest Italian warships having been constructed here. The city has a technical institute, a school of navigation, and a marine hospital. Considerable trade is carried on, chiefly in olive oil, wine, fruits, and marble. There are manufactures of furniture, hemp-linen, and leather. Spezia is near the site of the an- cient Luna, of which some remains exist. Popula- tion (commune), in 1881,30,732; in 1901, 65,612. SPHACTE'RIA, or Sphagia. An island off the southwestern coast of Messenia, Greece, com- manding the entrance to the Bay of Navarino. SPHAGNUM (Neo-Lat., from Gk. aipayms, splidfinos, atpaKos, sphakos, (pdffKos, phaskos, (pacTKov, phaskon, sort of moss), or Bog Mos.s. A genus of mosses intermediate between the liver- worts and true mosses (see Musci) remarkable for their whitish or pale color. They often grow in considerable masses, absorbing water like sponge. Viut becoming friable when dry. They contribute much to the formation of peat, al- though peat from sphagnum alone is of poor ipiality. Gardeners employ them for covering and moistening the roots of plants because they read- ily absorb moisture from the air. The cells of the leaves are remarkable for their spiral struc- ture, and for large pores in their sides. See Plate of Bryophttes and Colored Plate under Husca. SPHENE (from Gk. (ripvv, sphen, wedge; so called from the shape of the crystals). One of the light-colored (yellow or green) varieties of titanite (q.v. ). SPHENISCI (NeoLat. nom. pi., from Gk. a(t>Tifl<TKOi. splu'iiiskos, diminutive of ff^riv, sphen, wedge). A group of birds, the penguins (q.v.). SPHENOID BONE (Gk. o-^Tji/oeioiJs. sphen- oeidis, wedge-shaped, from atprip, splUJn, wedge -h eldos, eidos, form). A bone situated at the an- terior part of the base of the skull, and articu- lated with. all the other cranial bones, which it wedges firmly together. It somewhat resembles a bat with its wings extended, and hence was termed the os vespertilionis. It is divisible into a body, the greater and lesser wings, and various processes. The greater wings present three sur- (^fi£ foramen. Slhinoidal sptite jft Spherwidal Sp/moiJal MrcirmmrU ■^l/loriUal fn/nz-tcrrwcral '" cresc VuUeutcartctl r/to-maxdlaiysujiacs
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Jtaygaid-Jiotcfi I I I Ptiryjo-palaiine groove Jvasal surrace 8PHEKOID BONE A8 SEEN FROM THE FKONT. faces: a superior or cerebral surface, forming part of the floor on which the brain rests; an anterior surface, which assists to form the outer part of the orbit of the eye : and an external sur- face with a rough ridge, giving attachment to the external pterygoid muscle, one of the most power- ful muscles of mastication. The second, third, fourth, fifth, and sixth cranial nerves emerge from the cranial cavity through foramina in this bone. SPHERE (Lat. spherra, from Gk. (ripatpa, sphaira. ball, globe; connected with Lith. spird, ball of dung, and perhaps with Skt. sphar, to hasten, styetch out). A solid bounded by a sur- face every point of which is at a given distance from a fixed point. The given distance is called the radius and the fixed point the centre of the sphere. A spherical surface may be generated by revolving a semi-circumference about its diam- eter. Sections of a sphere made by planes are circles. If the plane passes through the centre of the sphere, the circle is a great circle, other- wise a small circle of the sphere. If the seg- ments into which a plane divides a sphere are un- equal, the smaller is called the minor and the laj-ger the major segment. That portion of the spherical surface which is included between two parallel planes which cut or touch the surface is called a zone. The portion of a sphere gener- ated by the revolution of a circular sector about any diameter of its circle as an axis is called a spherical sector. The surface of a sphere is equal to four times the area of a great circle of the sphere, or 4irr^, r being the radius of the sphere. Its volume is i-irr'. The rectangular equation of a sphere, the origin being at the centre, is ay' + y' + sr = r^. ( See CooRniNATES.) (For the formulas for areas and volumes relating
