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galvanometer is meant the deflexion produced by a known electromotive force put upon its terminals or a known current sent through it. It is usual to specify the sensitiveness of a mirror galvanometer by requiring a certain deflexion, measured in millimetres, of a spot # light thrown on the scale placed at one metre from the mirror, when an electromotive force of one-millionth of a volt (microvolt) is applied to the terminals of the galvanometer; it may be otherwise expressed by stating the deflexion produced under the same conditions when a current of one microampere is passed through the coil. In modern mirror galvanometers a deflexion of 1 mm. of the spot of light upon a scale at 1 metre distance can be produced by a current as small as one hundred millionth (Io-*) or even one ten thousand millionth (Io-") of an ampere. It is easy to produce considerable sensitiveness in the galvanometer, but for practical purposes it must always be controlled by the condition that the zero remains fixed, that is to say, the s: needle or coil must come back to exactly the same position when no current is passing through the instrument. Other important qualifications of a galvanometer are its time-period and its dead-beatness, For certain purposes the needle or coil should return as quickly as possible to the zero position and with either no, or very few, oscilla; tions. If the latter condition is fulfilled the galvanometer is said to be “dead-beat.” On the other hand, for some pur the galvanometer is required with the opposite quality, that is to say, there must be as little retardation as possible to the needle or coil when set in motion under an impulsive blow. Such a galvanometer is called “ballistic.” The quality of a galvanometer in this respect is best estimated by taking the logarithmic decrement of the oscillations when the movable system is set swinging. This last term is defined as the logarithm of the ratio of one swing to the next succeeding swing, and a galvanometer of which the logarithmic decrement is large, is said to be highly damped. For many purposes, such as for resistance measurement, it is desirable to have a galvanometer which is highly damped; this result can be obtained by affixing to the needles either '#' of mica, when it is a £ needle galvanometer, or by winding the coil on a silver frame when it is a movable coil galvanometer. On the other hand, for the comparison of capacities £ and for other purposes, a galvanometer is required which is as little damped as ible, and for this purpose the coil must have the smallest possible frictional resistance to its motion through the air. In this case the moment of inertia of the movable system must be dec or the control strengthened... The Einthoven string galvanometer is another form of sensitive instrument for the measurement of small direct currents. It consists of a fine wire or silvered quartz fibre stretched in a strong magnetic field. When a current passes through the wire it is displaced across the field and the displacement is observed with a microscope. For the measurement of large currents a "tangent galvanometer.” is employed (fig. 3). Two fixed circular coils are placed apart at a distance equal to the radius of either coil, so that a
: current passing through them creates in the central :* region between them a nearly uniform magnetic field.
At the centre of the coils is suspended a small magnetic needle the length of which should not be greater than I's, the radius of either coil. The normal position of the needle is at right angles to the line joining the centre of the coils. If a current is through the cóils, the needle will be deflected, and the tangent of the angle of , its deflexion will be nearly proportional to the current passing t £ the coil, provided that the controlling, field is uniform in strength and direction, and that the length of the magnetic needle is so short that the space in which it £e is a practically uniform magnetic cloi. Alternating Current Galvanometers:For the detection of small alternating currents a magnetic needle or movable coil galvanometer is of no utility. We can, however, construct an instrument suitable for the purpose by suspending within a coil of insulated wire a small needle of soft iron placed with its axis at an angle of 45° to the axis of the coil. When an alternating current s £ the coil the soft iron needle tends to set itself in the direction of the axis of the coil, and if it is suspended by a quartz fibre or metallic wire so as to afford a control, it can become a metrical instrument. Another arrangement, devised by J. A. Fleming in 1887, consists of a silver or copper disk suspended within a coil, the plane of the disk being held at 45° to that of the coil. When an alternating current is through the coil, induced currents are set up in the disk, and the mutual action causes the disk to endeavour to set itself so that these currents are a minimum. This metal disk galvanometer has been made sufficiently sensitive to detect the feeble oscillatory electric currents set up in the receiving wire of a wireless telegraph apparatus. The Duddell thermal ammeter is another very sensitive form of alternating current galvanometer. In it the current to be detected or measured is passed through a high resist
Fig. 3.-Helmholtz Tangent Galvanometer.
ance wire or strip of metal leaf mounted on glass, over which is suspended a closed loop of bismuth and antimony, forming a thermoelectric couple. This loop is suspended by a quartz fibre in a strong magnetic field, and one junction of the couple is held just over the resistance wire and as near it as possible without touching. When an alternating current £ through the resistance it creates heat which in turn acts on the thermo-junction and generates a continuous current in the loop, thus deflecting it in the magnetic field. The sensitiveness of such a thermal ammeter can be made sufficiently great to detect a current of a few microamperes. REFERENCEs.-J. A. £ A Handbook for the Electrical Laboratory and Testing Room, vol. i. (London, 1901); W. E. Ayrton, T. Mather and W. E. Sumpner, "On Galvanometers," Proc. Phys. Soc. London (1890), Io, # H. R. Kempe, A Handbook of Electrical Testing (London, 1906); A. Gray, Absolute. Measurements in Electricity and Magnetism, vol. ii. part ii. (London, #. Useful information is also contained in the catalogues of all the principal electrical instrument makers-Messrs. Elliott Bros., Nalder, The Cambridge Scientific Instrument Company, Pitkin, Hartmann and Braun, Queen and others. (J GALVESTON, a city and port of entry and the county-seat of Galveston county, Texas, U.S.A., on the Gulf of Mexico, near the N.E. extremity of Galveston Island and at the entrance to Galveston Bay. It is about 48 m. S.E. of Houston and 310 m. W. of New Orleans. Pop. (1890) 29,084, (1900) 37,789, (6339 were foreign-born and 8291 negroes); (1910) 36,981; land area (1906) 7.8 sq. m. It is served by the Galveston, Houston & Henderson, the Galveston, Harrisburg & San Antonio, the Gulf, Colorado & Santa Fé, the Trinity & Brazos Valley, the International & Great Northern, and the Missouri, Kansas & Texas railways, and by numerous steamship lines to Gulf ports in the United States and Mexico, and to Cuba, South America, Europe and the Atlantic ports of the United States. Galveston Island is a low, sandy strip of land about 28 m. long and 1} to 33 m. wide, lying from 2 to 3 m. off the mainland. The city, which extends across the island from Gulf to Bay, faces and has its harbour on the latter. The island was connected with the mainland before the 1900 storm by a road bridge and several railway bridges, which, a short distance W. of the city, crossed the narrow strip of water separating the West Bay from Galveston Bay proper; the bridge least harmcd (a single-track railway bridge) was repaired immediately and was for a time the city's only connexion with the mainland, but in 1908 bonds were issued for building a concrete causeway, accommodating four railway tracks, one interurban car track, and a roadway for vehicles and pedestrians. An enormous sea-wall (completed in 1904 at a cost of $2,091,000) was constructed on the eastern and Gulf sides of the city, about 5 m. long, 17 ft. above mean low tide (1.5 ft. above the high-water mark of the storm of 1900 and 7.5 ft. above the previous high-water mark, that of September 1875), 16ft. wide at the base and 5 ft. at the top, weighing 20 tons to the lineal foot, and with a granite rip-rap apron extending out 27 ft. on the Gulfside. The entire grade of the city was raised from 1 to 15 ft. above the old level. Between the sea-wall and the sea there is a splendid beach, the entire length of which is nearly 30 m. Among the principal buildings are the city hall, the court-house, the masonic temple, the Federal custom-house and post-office, the Y.M.C.A. building and the publiclibrary. The United States government maintains a marine hospital, a live-saving station, an immigrant landing station, and the state and the Federal government separate quarantine stations. In addition to the Ball public high school, Galveston is the seat of St Mary's University (1854), the Sacred Heart and Ursuline academies, and the Cathedral school, all under Roman Catholic control. The government of the municipality was long vested in a council of ward aldermen, controlled by a “machine,” which was proved corrupt in 1894 by an investigation undertaken at the personal expense of the mayor; it gave place in 1895 to a city council of aldermen at large, which by 1901 had proved its inefficiency especially in the crisis following the storm of the preceding year. Government then seemed a business question and was practically undertaken by the city's commercial experts, the Deepwater commission, whose previous aim had been harbour improvement, and who now drew up a charter providing for government by a board of five appointed by the governor of the state. A compromise measure making three members appointees same name, is more remarkable for scenic beauty than for extent. Besides these perennial lakes, there are several low tracts, called turloughs, which are covered with water during a great part of the year. Loughs Mask and Corrib are connected by a salmon ladder, and contain large trout. Galway, with the Screab Waters, draining into Camus Bay, a branch of Kilkieran Bay, with Recess and the Ballynahinch waters, are the best fishing centres. On account of its scenic beauty, both coastal and inland, together with its facilities for sport, county Galway is frequented by summer visitors. Though for long the remoter parts were difficult of access, as in the case of Donegal, Mayo, Clare and the western counties generally, the Galway and Clifden railwayassisted private enterprise to open up the country. The western mountains, broken by deep landlocked and island-sheltered bays, as well as by the innumerable small loughs of the Connemara districts, afford scenes varying from gentle slopes occasionally well wooded along the water's edge to wild, bare moorlands among the heights, while the summits are usually bold and rocky cones. Several small fishing villages have acquired the dignity of watering-places from the erection of hotels, which have also been planted in previously untenanted situations of high scenic attractions; among these may be mentioned Leenane at the head of Killary harbour, Renvyle House at its entrance, Letterfrack on Ballynakill Bay, Streamstown and Clifden, and Cashel on Bertraghboy Bay. Inland are Recess, near Lough Derryclare, and Ballynahinch, on the lough of that name, both on the railway, at the foot of the Twelve Pins.
Geology.—The east of this county lies in the Carboniferous Limestone plain, with domes of Old Red Sandstone rising near Dunmore and Mount, Bellew. As Galway town is neared, the grey rock £ £ on the surface, and Lough Corrib spreads itself over almost level land. Its west branches, owever, run up into “Dalradian" hills, which rise abruptly on the threshold of Connemara. A broad mass of ice-worn gneiss and granite lies between Lough Corrib and Galway Bay, cut off so sharply at the sea as to suggest the presence of an east-and-west line of fracture. The Twelve Bens owe their supremacy to the quartzites, which are here well bedded and associated with limestone and mica-schist. Silurian conglomerates and sandstones, with andesitic lavas, overlie the Dalradians, with marked unconformity, south of Leenane and round Lough Nafooey. The surfaces of the hard rocks admirabl
record the action of ice throughout the county. There is black.
Carboniferous marble at Menlough near Galway; and the well-known “Connemara Marble" is a banded serpentinouscrystalline limestone in the Dalradians at Recess, Ballynahinch and Streamstown. Compact red granite is worked at Shantallow, and the region west of Galway contains many handsome porphyritic red varieties: Climate and Industries.—The climate is mild and healthy but variable, and violent winds from the west are not uncommon. Frost or snow seldom remains long on the western coast, and cattle of every description continue unhoused during the winter. The eastern part of the county produces the best wheat. Oats are freuently sown after potatoes in moorish soils less adapted for wheat. he flat shores of the bays afford large supplies of seaweed for manure....Limestone, gravel and marl are to be had in most other arts. When a sufficient quantity of manure for potatoes cannot e had, the usual practice is to pare and burn the surface. In many places on the £ fine early potatoes are raised in deep sea-sand manured with seaweed, and the crop is succeeded by barley, Those parts of the eastern district less fitted for grain are employed in asturage. Heathy sheep-walks occupy a very large tract between £ and Galway. An extensive range from Athenry, stretching to Galway Bay at Kinvarra, is also chiefly occupied by s £ Over half the total acreage of the county is pasture-land, and cattle; sheep, pigs and poultry are extensively reared. . The proportion of tillage to pasturage is roughly as one to four; and owing to the nature of the country fully one-third of the total area is quite barren. Manufactures are not carried on beyond the demand caused b the domestic consumption of the people. Coarse friezes, flannels and blankets are made in all parts and sold # in Galway and Loughrea. Connemara has been long celebrated fo £ stockings. . Coarse linen, of a narrow breadth, called bandle linen, is also made for home consumption. There is a linen-weaving factory at Oughterard. The manufacture of kelp, formerly a great source of profit on the western shores, is still carried on to some extent. Feathers and sea-fowls' eggs are brought in great quantities from the islands of Aran, the produce of the puffins and other seafowl that frequent the cliffs. Fishing affords occupation to many of the inhabitants, the industry having as its centres the ports of Galway and Clifden. The Midland Great Western main line enters the county at Ballinasloe, and runs by Athenry to Galway, with an extension £cité'a'
Western line from Sligo to Limerick traverses N. to S., by way of '' Athenry and the * from Population and Administration.—The population of county Galway (211,227 in 1891; 192,549 in 1901) decreased by more than half in the last seventy years of the 19th century, and the decrease continues, as emigration is heavy. About 97% of the population are Roman Catholics, and a somewhat less percentage are rural. The Erse tongue is maintained by many in this remote county. The chief towns are Galway (pop. 13,426), Tuam (3012), Ballinasloe (4904) and Loughrea (2815), with the smaller towns of Portumna, Gort, Clifden, Athenry, Headford, Oughterard and Eyrecourt. The county is divided into four parliamentary divisions (returning one member each); north, south, east and Connemara, while the town of Galway returns one member. There are eighteen baronies. Assizes are held at Galway, quarter-sessions at Galway, Ballinasloe, Clifden, Gort, Loughrea, Oughterard, Portumna and Tuam. The county comprises parts of the Protestant dioceses of Tuam and of Killaloe; and of the Roman Catholic dioceses of Elphin, Galway, Clonfert and Killaloe. History.—The history of county Galway is exceedingly obscure, and nearly every one of its striking physical features.carries its legend with it. For centuries local septs struggled together for mastery undeterred by outside influence. The wreck of part of the Spanish Armada on this coast in 1588 left survivors whose influence is still to be traced. The formation of Galway into a county was effected about 1579 by Sir Henry Sydney, lord deputy of Ireland. In the county at Aughrim (q.v.) the decisive battle of the English Revolution was fought in 1691. Among the antiquities are several round towers. The only perfect one is at Kilmacduagh, a very fine example 112 ft. high, leaning considerably out of the perpendicular. Raths or encampments are numerous and several cromlechs are to be seen in good preservation. The ruins of monastic buildings are also numerous. That of Knockmoy, about 6 m. from Tuam, said to have been founded in 1180 by Cathal O'Connor, was adorned with rude fresco paintings, still discernible, which were considered valuable as being the best authentic representations existing of ancient Irish costumes. Ancient castles and square towers of the AngloNorman settlers are frequently met with; some have been kept in repair, but the greater number are in ruins. The castle of Tuam, built in 1161 by Roderick O'Connor, king of Ireland, at the period of the English invasion, is said to have been the first building of this description of stone and mortar in Ireland. The remains of a round castle, a form of building very uncommon in the military architecture of the country, are to be seen between Gort and Kilmacduagh. The extraordinary cyclopean and monastic ruins on the Aran Islands (q.v.) must be mentioned; and the town of Galway, Athenry, and the neighbourhood of Ballinasloe all show interesting remains. The small church of Clonfert, in the south of the county, with a fine Romanesque doorway, is a cathedral, the diocese of which was united with Kilfenora, Kilmacduagh and Killaloe in 1833. GALWAY, a seaport, parliamentary borough and the county town of county Galway, Ireland, on the north shore of Galway Bay, and on the main line of the Midland Great Western railway. Pop. of urban district (1901) 13,426. Some of the streets are very narrow, and contain curious specimens of old buildings, chiefly in antique Spanish style, being square, with a central court, and a gateway opening into the street. The most noteworthy of these is the pile known as Lynch's Castle. This residence takes its name from the family of whom James Lynch Fitzstephen, mayor of Galway in 1493, was a member; whose severity as a magistrate is exemplified in the story that he executed his own son, and thus gave origin (according to one of several theories) to the familiar term of Lynch law. The principal streets are broad and contain goodshops. St Nicholas church is a fine cruciform building founded in 1320, and containing monuments, and a bell, one of a peal, which appears to have been brought from Cavron in France, but how this happened is not known. The church was made collegiate in 1484, and Edward VI. created the Royal College of Galway in connexion with it;
Cabral, but was afterwards transferred to da Gama, who received the title admiral of India (January 1502). A few weeks later the fleet sailed, and on reaching Calicut da Gama immediately bombarded the town, treating its inhabitants with a savagery too horrible to describe. From Calicut he proceeded in November to Cochin, “doing all the harm he could on the way to all that he found at sea,” and having made favourable trading terms with it and with other towns on the coast, he returned to Lisbon in September 1503, with richly laden ships. He and his captains were welcomed with great rejoicings and he received additional privileges and revenues. Soon after his return da Gama retired to his residence in Evora, possibly from pique at not obtaining so high rewards as he expected, but more probably in order to enjoy the wealth and position which he had acquired; for he was now one of the richest men in the kingdom. He had married, probably in 15oo, a lady of good family, named Catherina de Ataide, by whom he had six sons. According to Correa, he continued to advise King Emanuel I. on matters connected with India and maritime policy up to 1505, and there are extant twelve documents dated 1507– 1522 which prove that he continued to enjoy the royal favour. The most important of these is a grant dated December 1519 by which Vasco da Gama was created count of Vidigueira, with the extraordinary privileges of civil and criminal jurisdiction and ecclesiastical patronage. During this time the Portuguese conquests increased in the East, and were presided over by successive viceroys. The fifth of these was so unfortunate that da Gama was recalled from his seclusion by Emanuel's successor, John III., and nominated viceroy of India, an honour which in April 1524 he left Lisbon to assume. Arriving at Goa during September of the same year, he immediately set himself to correct with vigour the many abuses which had crept in under the rule of his predecessors. He was not destined, however, to prosecute far the reforms he had inaugurated, for, on the Christmas-eve following his arrival, he died at Cochin after ashort illness, and was buried in the Franciscan monastery there. In 1538 his body was conveyed to Portugal and entombed in the town of Vidigueira. In 188o what were supposed on insufficient evidence to have been his remains were transferred to the church of Santa Maria de Belem. His voyage had the immediate result of enriching Portugal, and raising her to one of the foremost places among the nations of Europe, and eventually the far greater one of bringing to pass the colonization of the East by opening its commerce to the Western world. BIBLIography.-Vasco da Gama's First Voyage, by Dr E. Ravenstein (London, Hakluyt Society, 1898), is a translation with notes, &c., of the anonymous Roteiro (Journal or Itinerary), written by one of Vasco da Gama's subordinates who sailed on board the “S. Raphael," which was commanded by the admiral's brother Paulo da Gama. This is the most important of the original authorities; five accounts of the voyage in letters contemporary with it are appended to the Hakluyt Society's translation. See also J. de Barros, Decadas da India (Lisbon, 1778-1788, written £: 1540): F. L. de Castanheda, Historia do descobrimento da India (Coimbra, 1551, largely based on the Roteiro); The Three Voyages of Vasco da Gama and his Viceroyalty, by Gaspar Correa (Hakluyt Society, 1869), chiefly valuable for £e events of 1524; The Lusíads of Camoens, the central incident in which is Vasco da Gama's first voyage; Calcoen (i.e. Calicut), a Dutch Narrative of the Second Voyage of Vasco da Gama, written by some unknown seaman of the expedition, printed at Antwerp £ 1504, reprinted in facsimile, with introduction and translation, by J. Ph. Berjeau (London, 1874); Thomé Lopes, narrative (1502) in vol. i. of Ramusio. GAMALIEL (*). This name, which in Old Testament times figures only as that of a prince of the tribe of Manasseh (vide Num. i. 10, &c.), was hereditary among the descendants of Hillel. Six persons bearing the name are known. 1. GAMALIEL I., a grandson of Hillel, and like him designated Ha-Zāqên (the Elder), by which is apparently indicated that he was numbered among the Sanhedrin, the high council of Jerusalem. According to the tradition of the schools of Palestine Gamaliel succeeded his grandfather and his father (of the latter nothing is known but his name, Simeon) as Nasi, or president of the Sanhedrin. Even if this tradition does not correspond with historic fact, it is at any rate certain that Gamaliel took a leading
position in the Sanhedrin, and enjoyed the highest repute as an authority on the subject of knowledge of the Law and in the interpretation of the Scriptures. He was the first to whose name was prefixed the title Rabban (Master, Teacher). It is related in the Acts of the Apostles (v. 34 et seq.) that his voice was uplifted in the Sanhedrin in favour of the disciples of Jesus who were threatened with death, and on this occasion he is designated as a Pharisee and as being “had in reputation among all the people” (vouojićāaka Mos riuos Tavri rig Aa3). In the Mishna (Gittin iv. 1-3) he is spoken of as the author of certain legal ordinances affecting the welfare of the community (the expression in the original is “tiqqun ha-'alim,” i.e. improvement of the world) and regulating certain questions as to conjugal rights. In the tradition was also preserved the text of the epistles regarding the insertion of the intercalary month, which he sent to the inhabitants of Galilee and the Darom (i.e. southern Palestine) and to the Jews of the Dispersion (Sanhedrin 11b and elsewhere). He figures in two anecdotes as the religious adviser of the king and queen, i.e. Agrippa I. and his wife Cypris (Pesahim 88b). His function as a teacher is proved by the fact that the Apostle Paul boasts of having sat at the feet of Gamaliel (Acts. xxii. 3). Of his teaching, beyond the saying preserved in Aboth i. 16, which enjoins the duty of study and of scrupulousness in the observance of religious ordinances, only a very remarkable characterization of the different natures of the scholars remains (Aboth di R. Nathan, ch. xl.). His renown in later days is summed up in the words (Mishna, end of Sotah): “When Rabban Gamaliel the Elder died, regard for the Torah (the study of the Law) ceased, and purity and piety died.” As Gamaliel I. is the only Jewish scribe whose name is mentioned in the New Testament he became a subject of Christian legend, and a monk of the 12th century (Hermann the Premonstratensian) relates how he met Jews in Worms studying Gamaliel's commentary on the Old Testament, thereby most probably meaning the Talmud. 2. GAMALIEL II., the son of Simon ben Gamaliel, one of Jerusalem's foremost men in the war against the Romans (vide Josephus, Bellum Jul. iv. 3, 9, Vita 38), and grandson of Gamaliel I. To distinguish him from the latter he is also called Gamaliel of Jabneh. In Jabneh (Jamnia), where during the siege of Jerusalem the scribes of the school of Hillel had taken refuge by permission of Vespasian, a new centre of Judaism arose under the leadership of the aged Johanan ben Zakkai, a school whose members inherited the authority of the Sanhedrin of Jerusalem. Gamaliel II. became Johanan ben Zakkai's successor, and rendered immense service in the strengthening and reintegration of Judaism, which had been deprived of its former basis by the destruction of the Temple and by the entire loss of its political autonomy. He put an end to the division which had arisen between the spiritual leaders of Palestinian Judaism by the separation of the scribes into the two schools called respectively after Hillel and Shammai, and took care to enforce his own authority as the president of the chief legal assembly of Judaism with energy and often with severity. He did this, as he himself said, not for his own honour nor for that of his family, but in order that disunion should not prevail in Israel. Gamaliel's position was recognized by the Roman government also. Towards the end of Domitian's reign (c A. D. 95) he went to Rome in company with the most prominent members of the school of Jabneh, in order to avert a danger threatening the Jews from the action of the terrible emperor. Many interesting particulars have been given regarding the journey of these learned men to Rome and their sojourn there. The impression made by the capital of the world upon Gamaliel and his companions was an overpowering one, and they wept when they thought of Jerusalem in ruins. In Rome, as at home, Gamaliel often had occasion to defend Judaism in polemical discussions with pagans, and also with professed Christians. In an anecdote regarding a suit which Gamaliel was prosecuting before a Christian judge, a converted Jew, he appeals to the Gospel and to the words of Jesus in Matt. v. 17 (Shabbath 116 a, b). Gamaliel devoted special attention to the regulation of the rite of prayer, which after the