ting to sea. Few subjects have more seriously engaged the attention of nautical men. In the land forces, signals are made by the firing of cannon, or by sound of trumpet. Balloons are sometimes used for signals. (For the Telegraph, see that article.)

SIGNATURE; among printers, a letter or figure at the bottom of the first page of a sheet or half sheet, by which the order of the sheets is designated, so as to guide the binder. Every successive sheet has a different letter or figure; and, where letters are employed, if the sheets are more numerous than the letters of the alphabet, then a small letter is added to the capital one, as, A a, Bb, &c. In large volumes, the signatures are sometimes composed of letters and figures, thus, 5 A, 5 B. It is more common, however, at present, to use only figures.

SIGNET; one of the king's seals, made use of in sealing his private letters, and all grants that pass by bill, signed under his majesty's hand. It is always in the custody of the secretaries of state. (See Seal.)

SIKHS, OF SEIKS; a religious sect in Hindoostan, which professes the purest Deism. It is chiefly distinguished from the Hindoos by worshipping one only and invisible God. It was founded by the estimable Nanac Shah, of the caste of Cshatriyas and the Hindoo tribe of the Vedis, who was born A. D. 1469, in the village of Talwandi (now the town of Rajapoor), in the province of Lahore. When Nanac was very young, he met some fakirs, who converted him to the Nagornai worship, which consists in the adoration of one God. His lively imagination made him dissatisfied with traffic; and, to gratify his thirst for knowledge, he travelled through Hindoostan, Persia, and Arabia, visited Medina and Mecca (the Mohammedan places of pilgrimage), and the sacred sects of the Hindoos in Vatala, and the Picos (Mohammedan saints) in Moultan. Afterwards he became acquainted with the system of the Ssufi, and adopted their doetrines. He read, particularly, the works of a Mohammedan named Cabik, belonging to this sect, who enjoined, in all his writings, universal philanthropy, and, particularly, religious toleration. Nanac now renounced all worldly business, and consecrated his life to the purest devotion. He entertained the noble and benevolent idea of effecting a union between the Hindoos and Mohammedans, by introducing simplicity of faith and purity of >rals. Hence he treated both religions

with respect, labored to remove only what was superfluous and dissonant, and to lead the people to a practical religion, to a pure worship of God, and love to mankind. Thus he used to say, "Hundreds of thousands of Mohammeds, millions of Brahmas and Vishnoos, and hundreds of thousands of Rahmas, stand before the throne of the Almighty, and they all die. God alone is immortal. He only is a good Hindoo who is just, and a good Mohammedan whose life is pure." Nanac died about 1540, at Kirtipur, where he lies buried on the banks of the Ravee. Hence Kirtipur i deemed a sacred place by the Sikhs; and a relic of Nanac's dress is preserved in his temple there, which is shown to pilgrims. The ennobling religion established by Nanac, and the benevolence of his doctrines, corresponded to the purity of his whole life. Far from deceiving his adherents with pretended miracles, he replied to the Yogiswares (to whom a dominion over the powers of nature, procured by selftorture, is attributed in Hindoostan), when they importuned him to perform a miracle, "I have nothing worth showing. A holy teacher has no defence but the purity of his doctrines. The world may alter, but the Creator is unchangeable." As a governor and priest, he exercised, during his life, a spiritual and temporal dominion over his disciples. At his death, he transferred the power, not to his sons, but to s favorite disciple named Lehana, whom he had himself initiated into his doctrines, and dressed in the sacred garb of a fakir. Of his successors in the government of the Sikhs, Arjun gave stability to the religion, and unity to its professors, by collecting the writings of Nanac, and publishing the A'di Grant'h, the first sacred book of the sect. But this drew upon him the notice and the jealousy of the Mohammedan government, and he was put to death. Eager to avenge his father's death, Har Govind, the son and successor of Arjun, transformed the Sikhs from peaceful believers into valiant warriors: and, under his reign, and that of his pos terity, a bloody contest was maintained between them and the Mohammedans, till the day of Behadur's execution, whose son, Guru Govind, was forced to retreat with his adherents to the Punjab, where a Hindoo chief kindly entertained him, and gave him Mekhamel, on the banks of the Setledge. Guru Govind established there the state of the Sikhs, destroying among them the Hindoo distinction of castes, and giving equal rights to the lowest Soodra and the highest Brahmin. This pro

cured him great accessions to the numbers of his disciples, whom he excited to seek for happiness in this and the future world by destroying the tyrannical Mohammedans. From this time, in consequence of their heroic conduct during the protracted contest with their oppressors, Guru Govind's followers received the title of Sikhs or lions, which before had been confined to the Rajaputs, as the first military order among the Hindoos. This ruler, equally great as a soldier and a lawgiver, wrote the Dasema Padshah ke Grant'h, or the book of the tenth prince (so called because he was the tenth ruler of the Sikhs from Nanac). Besides treating of religious subjects, it contained also the history of the author's exploits. It is regarded by the sect with the same veneration as the Adi Grant'h of Arjun. Guru Govind directed the Sikhs, in order to distinguish them for ever from Mohammedans and Hindoos, to wear a blue dress, to let their hair grow, and to be always armed. To make his religious institutions more stable, he founded a religious order, the acalis (immortals), and assigned the members of it a bonga (monastery) by the sacred fountain at Emoilser, on the income of which they were supported. To these acalis he committed the care of converting and initiating new Sikhs; and in their hands still rests the supreme direction of all the religious and civil affairs. Guru Govind was the last head of the Sikhs; for a prophecy limited the number of the rulers to ten; and as he was the tenth ruler after Nanac, he said to his friends, on his death-bed, "I commit the state to God, who never dies." Hence the Sikhs suppose that their state is under the peculiar care of the Deity. Their government, therefore, is a pure theocracy. The popular faith would prove an insurmountable obstacle to any one who should attempt to subject the Sikhs to his rule. After the death of Guru Govind, the Sikhs gradually yielded to the superior power of the Mohammedans; and even Banda, one of their most heroic leaders, after a fearful struggle, was taken prisoner in the fort of Lagab, with all his followers, sent to Delhi, and put to death with the most barbarous tortures. To exterminate at length the hated sect, a price was set upon their head by the Mohammedan government, and every adherent of it, who could be taken, was put to death. But they suffered, with the greatest firmness, the pains of martyrdom, often courting, rather than fleeing from them. Nothing could induce them to renounce their faith; and a Ma

hommedan writer has stated that no Sikh who was taken on the pilgrimage to Amritsar (the holy place of the Sikhs) ever abjured his religion to save his life. A very small number of the Sikhs escaped to inaccessible mountains, and faithfully preserved the doctrines of their fathers, and an inextinguishable hatred towards their persecutors. After Nadir Shah's return to Persia, they ventured to leave the mountains; and, taking advantage of the confusion into which Nadir's expedition had plunged Hindoostan, they subdued all Lahore. At present, the territory of the Sikhs extends from 28° 40′ to beyond 30° north latitude, and comprehends all the Punjab, a part of Moultan, and the largest portion of the country lying between the Jumnah and the Setledge, or the north-western corner of Hindoostan, containing 69,000 square miles, and 4,000,000 inhabitants. A few chiefs, who form a diet at Amritsar, and deliberate on subjects of general interest, under the direction of the acalis, rule over portions of country of greater or less extent. According to the account of general Malcolm, who was in the Punjab with the British army in 1805, and to whom we are indebted for the most accurate information concerning this interesting sect (see vol. xi of the Asiatic Researches, containing his Sketch of the Sikhs, also printed separately in 1812), they are able to bring into the field 100,000 horse. Their present governor, or maha raja, is said to have subjected portions of Afghanistan and Cashmire to his rule. In the separate districts, subordinate chiefs, or sirdars, possess unlimited power. Lahore is the residence of the chief ruler, and contains 100,000 inhabitants. The city of Amritsar is the great depot of Cashmere shawls and of saffron.

SILENUS; the tutor and companion of Bacchus; according to some, the son of Mercury, or of Pan, by a nymph; according to others, he sprang from the blood of Uranus. According to Pindar, his wife was the nymph Nais; according to others, a nymph of Malea, in the island of Lesbos, who bore him the Arcadian Centaur Pholus. He educated Bacchus, instructed him in the sciences, and was ever afterwards his constant companion. He loved the inspiring beverage of his pupil's invention so well, that he was generally intoxicated; and in this plight he was found by two young Satyrs, who bound him with garlands, and compelled him to sing. Midas caught him in the same condition, and entered into a philosophical conversation with him. In the

war of the giants, Silenus aided the gods, and terrified their enemies by the braying of his ass. A whole race of Silenuses sprang from him. The name is often applied to old Satyrs of a cheerful, goodnatured disposition. They are represent ed with a curly beard, a low forehead, and bald head. The chief of the race is the companion of Bacchus above described, known by the cantharus or bottle which he bears. He is often also distinguished from the other Sileni, by being mounted on an ass, or by his accompanying Bacchus, and is frequently represented holding the infant Bacchus in his arms. He sometimes also appears treading out grapes, and covered with hair. In the latter case, a caricature is intended.

SILESIA (in German, Schlesien); formerly a duchy belonging to Bohemia, now divided, politically, between Prussia and Austria, and, geographically, into Upper and Lower Silesia. The Prussian province of Silesia (15,264 square miles; population, 2,396,551) borders on Posen and Poland to the east, on the Austrian territories to the south, and on Saxony and Brandenburg to the west and north. (See Prussia.) The southern part of the province is mountainous, being intersected by different ridges of the Sudetic chain. (q. v.) Towards Brandenburg and Posen it is level, but in part marshy and sandy, although throughout adapted to tillage. The principal river is the Oder. (q.v.) The soil of Silesia is fertile, yielding corn of all sorts, fruits, and tolerable wines. The mountainous parts are covered with wood, or afford good pasturage and meadow land. Flax is raised in large quantities, and affords an important article of manufacture and trade, and madder, hemp, hops and tobacco are among the productions of the province. The wool of Silesia is of the best sort produced in Prussia. Among the mineral productions are iron, copper, lead, some silver, sulphur, vitriol, &c., and there are mineral waters in several places. Linen is the principal article of manufacture, and owes its excellence to the inspection system, which has been introduced here. Cotton and woollen goods and leather are also manufactured to a great extent. Silesia is divided into three governments Breslau, Liegnitz and Oppeln. The inhabitants are chiefly Lutherans and Catholics, with some Calvinists, Hussites, Herrnhutters, Jews, &c. There is a university in Breslau (q. v.), the capital of the province, with two theological faculties, one for Catholics and the other for Protestants,

and numerous gymnasia, or high schools, in the large towns. The revenue is about six million dollars.-Austrian Silesia consists of the southern part of the old S lesian duchy, which was left to Austra by the peace of Hubertsburg, in 1763. h is divided into the circles of Teschen and Troppau, and attached to the Moravian gubernium of Brünn. Population,350,000; square miles, 2500. It is mountainous, and although the soil is not in all parts favorsble, it is rendered productive by the industry of the inhabitants, who are also extensively engaged in linen, cotton and woollen manufactures. In the sixth century, this country was occupied by Schvonians, who drove out the Lygi and Quadi, and thus annexed it to Poland. It was afterwards divided into a great number of petty principalities, and in the fourteenth century, it became a depen dency of Bohemia. (q. v.) Although, in consequence of its annexation to Bohe mia, it came to be considered a part of Germany, it never actually formed a menber of the empire. (For the more modern history of Silesia, see Frederic II, Seven Years' War, and Prussia.)

SILESIAN POETS. (See German Poetry.)

SILESIAN WARS. (See Frederic II, Maria Theresa, and Seven Years' War.

SILEX, or SILICA. The mineral spe cies quartz, it was mentioned under that article, consists almost exclusively of silex. It also forms a principal ingredient in nearly all the earthy minerals, and was regarded as one of the primitive earths, until after the discovery of the composi tion of the fixed alkalies by Davy, when it was ascertained, by this philosopher, to consist of oxygen and an unknown base, which has been called silicon, or silicium. If we ignite powdered quartz with three parts of pure potash in a silver crucible, dissolve the fused compound in water. add to the solution a quantity of muristic acid, sufficient to saturate the alkali and evaporate to dryness, we shall obtain a fine, gritty powder, which, being well washed with hot water, and ignited, will yield pure silex. By passing the vapor of potassium over silex, in an ignited tube, we obtain boron, the basis of the earth. Thus obtained, as well as by several other methods, silicon is of a deep brown color: is a non-conductor of electricity: it stains the fingers, and adheres to every thing that comes in contact with it. Like car bon and boron, it may be exposed to a very high temperature in close vessels, without fusion; but it becomes harder, the

greater the heat to which it has been subjected. By this treatment, its properties are very materially altered. Before it has been heated, it is readily combustible in the air, and burns with a very lively flame. By this combustion, about one third of it is converted into silica, while the rest is preserved by the silica formed, which prevents the unburnt portion from coming in contact with the atmosphere. Silex, or silica, is the only compound of silicon and oxygen with which we are acquainted. It is a white, tasteless powder, feeling gritty between the teeth, and having a specific gravity of 2.65. When originally formed by the combustion of silicon, it is so soluble in water, that the liquid, when concentrated, gelatinizes. But after it has been exposed to heat, it loses its solubility altogether. When silex is mixed with thrice its weight of potash, or with a quantity of carbonate of potash, containing thrice as much potash as the weight of silex employed, and the mixture is exposed to a strong heat, it fuses, and assumes, on cooling, the appearance of glass. This glass dissolves in water. If to an aqueous solution of it we add as much muriatic acid as will saturate the alkali, and concentrate the solution sufficiently, the silica assumes the form of a white translucent jelly. This characterizes silica. If we evaporate the whole to dryness, and wash off the salt of potash from the dry mass, the silica remains behind in the state of a very fine powder. Silex consists of about 48 silicon, and oxygen 52. It may be subjected to a very violent heat, without suffering any change; there is no difficulty in causing it to melt, however, before the compound blow-pipe. Though silex does not redden vegetable blues, yet it enters into definite compounds with the different bases, and forms saline compounds, which are distinguished by the name of silicates, and is hence called silicic acid by some writers on chemistry. Like other weak acids, it is capable of entering into a great variety of combinations with bases. The combinations which it forms are frequently so intimate, that no other acid is capable of removing the base and setting the silica at liberty. The different kinds of glass consist of two or more silicates melted together. Silicon burns vividly when heated in chlorine gas, and the compound formed is a colorless liquid, which is a chloride of silicon. It evaporates almost spontaneously, in the form of a white vapor, when exposed to the open air. It boils at a temperature below 212°. It red

dens litmus paper very strongly. When dropped into water, it swims on the surface of that liquid. It is gradually dissolved in the water, but deposits, at the same time, a little silica. Silicon unites with fluorine, and forms an acid gas, which is called fluosilicic acid. It is easily obtained by mixing together fluor spar and glass, or quartz, both in fine powder, in a small retort, and adding a sufficient quantity of sulphuric acid, to form the whole into a semi-fluid mass. When heat is applied to this mixture, fluosilicic acid comes over in the form of a transparent invisible gas. This gas is rapidly absorbed by water, while silica is deposited in a gelatinous state. Its specific gravity is 3.6. It consists of fluoric acid 17.6, silica 27.2. When potassium is heated in it, combustion takes place, and a chocolate-colored substance is formed, which differs in its nature, according to the proportion of potassium employed. Fluosilicic acid gas combines with twice its volume of ammoniacal gas, forming a volatile salt. Silicon and carbon combine, when they come in contact in a nascent state. The carburet formed is a dark brown powder. Sulphuret of silicon is formed by heating silicon in the vapor of sulphur, and the union is attended with the phenomena of combustion. It is a white, earthy-looking substance, which is instantly converted by the action of water into sulphureted hydrogen and silica. Silicon is more allied to carbon and boron than to the metals.

SILHOUETTE is the representation of the outlines of an object filled with black color, in which the inner lines are sometimes slightly drawn in white. The name comes from Etienne de Silhouette, French minister of finance in 1759. He strove by severe economy to remedy the evils of a war which had just terminated, leaving the country in great exhaustion. At the end of nine months, he was obliged to leave his place. During this period, all the fashions in Paris took the character of parsimony. Coats without folds were worn; snuff-boxes were made of plain wood; and, instead of painted portraits, outlines only were drawn in profile, and filled with Indian ink, &c. All these fashions were called à la Silhouette; but the name remained only in the case of the profiles, because the ease with which they may be drawn, or cut out of black paper, makes them popular, though, considered as works of art, they have little value. Some faces-those with a marked profile-are easily taken in this way, whilst others lose their character entirely,

particularly those whose traits are well harmonized. In general, the extremes of expressions, as the expression of great savageness or sternness, great mildness or obstinacy, deep reflection, or great stupidity, are those most easily given in this mode. But the expression of blended imagination, thought, and goodness of disposition, is not easily conveyed in profile. On the whole, the silhouette expresses more the original disposition of the mind, than its cultivated character. These representations may be taken very well from the shadow of a person on a paper held on the wall; and in order to make the shadow more steady, it is well to rest the head on a book or the like, put between the face and the paper. The paper is then cut according to the outline of the shadow, and the outer surface pasted on black paper. The likeness can be taken still better, and of any size, by means of an instrument called a pantograph. A frame with a glass, on which paper slightly oiled and well dried is fastened, attached to a chair on which the person sits, whose likeness is to be taken, is also of much advantage. The invention of the silhouette, in ancient times, is said to have given rise to the art of painting. This invention is ascribed to the daughter of the potter Dibutades, who drew the outline of her lover's shadow on the wall. The time of this invention may be placed at the renewal of the Olympic games, shortly before the expulsion of the Bacchiades from Corinth, about 776 B. C. Sicyon and Corinth were the first places where paint ing flourished. Crato of Sicyon, Philocles of Egypt, and Cleanthes of Corinth, are mentioned as inventors of the monochromes (q. v.), they having filled the outline with colors. The silhouettes were soon applied to large objects; thus Saurias of Samos drew the shadow of his horse on a wall. The estimation of these drawings with the ancients, the beauty and delicacy with which they were executed, may still be seen from the Etrus

can vases.

SILICATE OF MANGANESE; the name of a chemical family in mineralogy, which consists of two mineralogical species, viz. the Fowlerite and the manganese spar, or siliceous oxide of manganese. The Fowlerite occurs in feldspar-looking crystals, differing, however, in the valve of its angles, from feldspar. Its angles are 95° 0, 121° 0, and 113 0. Its hardness is the same as feldspar; specific gravity 3.5 to 3.8; color flesh-red. It is fusible with

It is found in crystals of considerable size, and in foliated and granular masses, at Franklin, New Jersey, accompanied by Franklinite and magnetic iron ore. also occurs at Cumberland in Rhode Island. The manganese spar occurs mas sive, fine, granular, and, rarely, somewhat fibrous; color rose-red; lustre interme diate between pearly and resinous; translucent; hardness but little inferior to feadspar; specific gravity, 3.5. Heated before the blow-pipe, it becomes dark-brown, and melts into a reddish globule. It tinges borax hyacinth-red. It consists of

It is found in primitive districts, usually in connexion with beds of iron ore. Localities of it exist in the Hartz, in Sweden, and in Devonshire, England. It has been discovered in large quantities in Massachusetts, at Cummington, in isolated mas es, from one foot to two feet in diameter. This species is sometimes wrought into articles of ornament. When polished, its color and lustre are extremely delicate.

SILIUS, Caius, surnamed Italicus, was born in the reign of Tiberius, about the year 15. The origin of his surname uncertain. At Rome, he applied himself to the bar, and became a celebrated orstor and advocate. He was consul at the time of Nero's death, and incurred some reproach for assisting in that tyrant's pros ecutions, but acquired honor from has conduct in the proconsulate of Asia, assigned to him by Vespasian, from which he retired into private life, and collected books, statues, and busts of eminent men. He finally retired to his seat in Campania, where, being seized with an incurabi ulcer, he put an end to his life by starvation, in his seventy-fifth year. The only work of Silius which has reached modern times, is an epic poem on the second Punic war, in sixteen books, written with more diligence than genius. It contains, however, occasional splendid passages. and his description of the passage si Hannibal across the Alps is particularty