Market, London. This was done by the crown-bar method, | general, the upper half of the tunnel was executed first (figs. 9 the bars being built in with solid brickwork. The subsidence and 10) and the lower part completed by underpinning. in the ground was from 1 to about 3 in. Several buildings were tunnelled under without any structural damage. London has now some 90 m. of tunnels for railways, mostly operated by electric traction. Most of those which have been constructed since 1890 have been tunnelled by the use of cylindrical shields and walls of cast iron. Shields about 23 ft. in diameter were used in constructing the stations on the Central London railway, and one 32 ft. 4 in. in diameter and only 9 ft. 3 in. long was used for a short distance on the Clapham extension of the City and South London railway. Figs. 11, 12 and 13 illustrate a case of tunnelling near important buildings in Boston in 1896, with a roof-shield 29 ft. 4 in, in external diameter. The vertical sidewalls were first made in small drifts, the roof-shield running on top of these, and the core was taken out later and the invert or floor of the tunnel put in last. Each hydraulic press of the shield reacted against a small continuous cast-iron rod imbedded in the brick arch. In some large sewerage tunnels in Chicago the shields were pushed from a wall of oak planks, 8 in. thick, surrounding the brick walls of the sewer. The first application of mechanical or fan ventilation to railway tunnels was made in the Lime Street tunnel of the London and North-Western railway at Liverpool, which has since been replaced by an open cutting. At a later date fans were applied to the Severn and Mersey tunnels. The principle ordinarily acted upon, where mechanical ventilation has been adopted, is to exhaust the vitiated air at a point midway between the portals of a tunnel, by means of a shaft with which is connected a ventilating fan of suitable power and dimensions. In the case of the tunnel under the river Mersey (fig. 14) such a shaft could not be provided, owing to the river being overhead, but a ventilating heading was driven from the middle of the river (at which From a diagram in Proc. Inst. Cie. Eng.) FIG. 14.-Longitudinal Section of the Mersey Tunnel, showing Method of Ventilation. into the chimney from the fan has a line parallel to that of the fanshaft and of the fan-blades, and, as a consequence, as each blade passes this shutter, the stoppage of the discharge of the air is instantaneous, and the suaden change of the pressure of the air on the face of the blade whilst discharging and the reversal of the pressure, due to the vacuum inside the fan-casing, cause the vibration hitherto inseparable from this type of ventilator. As an illustration of the effect of the pulsatory action of the Guibal shutters the following figures may be given: a fan having ten arms and running, say, sixty revolutions per minute, and working twenty-four hours per day, gives (10 X 60 X 60 X 24) 864,000 blows per day transmitted from the tip of the fan-vanes to the fan-shaft; the shaft is thus in a constant state of tremor, and sooner or later reaches its elastic limit, and the consequent injury to the general structure of the fan is obvious. This difficulty is avoided by cutting a Ʌ-shaped opening in the shutter, thus gradually decreasing the aperture and allowing the air to pass into the chimney in a continuous stream instead of intermittently. The action of this regulating shutter increases the durability and efficiency of the fans in an important degree. In towns like Liverpool and Birkenhead any pulsatory action would be readily felt by the inhabitants, but with the above arrangement it is difficult to detect any sound whatever, even when standing close to the buildings containing the fans. The admission of the air on both sides is found in practice to conduce to smooth running and to the reduction of the side-thrust which occurs when the air is admitted on one side only. The fans are five in number: two are 40 ft. in diameter by 12 ft. wide, and two 30 ft. in diameter by 10 ft. wide, one of each size being erected at Liverpool and at Birkenhead respectively. In addition, there is a high-speed fan 16 ft. in diameter in Liverpool which throws 300,000 cub. It. The following table gives the result of experiments made with the ventilating fans of the Mersey railway: FIG. 15.-Section of Severn Tunnel (Fox). heading leading to the centre. This fan, which is 40 ft. in diameter by 12 it. in width, removes from the tunnel some 400,000 cub. ft. per minute, and draws in an equivalent volume of fresh air from the two ends. About 1896 an excellent system was introduced by Signor Saccardo, the well-known Italian engineer, which to a great extent has minimized the difficulty of ventilating long tunnels under mountain-ranges where shafts are not available. This system, which is not applicable to tunnels in which underground stations exist, is illustrated in fig. 16, which represents its application to the single-line tunnel through the Apennines at Pracchia. This tunnel is one of fiftytwo single-line tunnels, with a gradient of 1 in 40, on the main line between Florence and Bologna, built by Thomas Brassey. There is a great deal of traffic which has to be worked by heavy locomotives. Before the installation of a ventilating system under any condition of wind the state of this funnel, about 3000 yds, in length, was bad; dar drift-way a velocity of 4000 ft. per * In the case of minute was 2 FIG. 16.-Diagram illustrating the Saccardo System for steam, the wheels slipped and possibly the train stopped, the state of the air was indescribable. A heavy train with two engines, conveying a royal party and their suite, arrived on one occasion at the upper exit of the tunnel with both enginemen and both firemen insensible; and on another occasion, when a heavy passenger train came to a stop in the tunnel, all the occupants were seriously affected. In applying the Saccardo system, the tunnel was extended for 15 or 20 ft. by a structure either of timber or brickwork, the inside line of which represented the line of maximum construction, and this was allowed to project for about 3 ft. into the tunnel. The space between this line and the exterior constituted the chamber into which air was blown by means of a fan. Considering the length of tunnel it might at first be thought there would be some tendency for the air to return through the open mouth, but nothing of the kind happened. The whole of the air blown by the fan, 164,000 cub. ft. per minute, was augmented by the induced current yielding 46,000 cub. ft. per minute, making a total of 210,000 cub. ft.; and this volume was blown down the gradient against the ascending train, so as to free the driver and men in charge of the train from the products of combustion at the earliest possible moment. Prior to the installation of this system the drivers and firemen had to be clothed in thick woollen garments, pulled on over their ordinary clothes, and wrapped round and round the neck and over the head; but in spite of all these precautions they sometimes arrived at the upper end of the tunnel in a state of insensibility. The fan, however, immensely improved the condition of the air, which is now pure and fresh. In the case of the St Gotthard tunnel, which is 9} m. in length and 26 ft. wide with a sectional area of 603 sq. ft., the Saccardo system was installed in 1899 with most beneficial results. The railway is double-tracked and worked by steam locomotives, the cars being lighted by gas. The ventilating plant is situated at Göschenen at the north end of the tunnel and consists of two large fans operated by water power. The quantity of air passed into the narrow mouth of the tunnel is 413,000 cub. ft. per minute at section of the tunnel is reached. A sample of the air taken from a velocity of 686 ft., this velocity being much reduced as the full a carriage contained 10-19 parts of carbonic acid gas per 10,000 volumes. mechanical ventilation is installed. A steel sliding door is arranged In the Simplon tunnel, where electricity is the motive power, at each entrance to be raised and lowered by electric power. After the entrance of a train the door is lowered and fresh air forced into the tunnel at considerable pressure from the same end by fans. of ventilating intra-urban railways laid in tunnels at a greater or The introduction of electric traction has simplified the problem less distance below the surface, since the absence of smoke and products of combustion from coal and coke renders necessary only such a quantity of air as is required by the passengers and staff. For supplying air to the shallow tunnels which form the under ground portions of the Metropolitan and District railways in London. open staircases, blow-holes and sections of uncovered track are relied on. When the lines were worked by steam locomotives they afforded notorious examples of bad ventilation, the proportion of At east mouth carbonic acid amounting to from 15 or 20 to 60, 70 and even 89 | Up line, gradient rising I in 100- When deep level "tube" railways were first constructed in London, it was supposed that adequate ventilation would be obtained through the lift-shafts and staircases at the stations, with the aid of the scouring action of the trains which, being of nearly the same cross-section as the tunnel, would, it was supposed, drive the air in front of them out by the openings at the stations they were approaching, while drawing fresh air in behind them at the stations they had left. This expectation, however, was disappointed, and it was found necessary to employ mechanical means. On the Central London railway, which runs from the Bank of England to Shepherd's Bush, a distance of 6 m, the ventilating plant installed in 1902 consists of a 300 h.p. electrically driven fan, which is placed at Shepherd's Bush and draws in fresh air from the Bank end of the line and at other intermediate points. The fan is 5 ft. wide and 20 ft. in diameter, and makes 145 revolutions a minute, its capacity being 100,000 cub. ft. a minute. It is operated from 1 to 4 a.m., and the openings at all the intermediate stations being closed it draws fresh air in at the Bank station. The tunnel is thus cleared out about 2 times each night and the air is left in the same condition as it is outside. The fan is also worked during the day from II a.m. to 5 p.m., the intermediate doors being open; in this way the atmosphere is improved for about half the length of the line and the cars are cleared out as they arrive at Shepherd's Bush. Samples of the air in the tunnel taken when the fan was not running contained 7 07 parts of carbonic acid in 10,000, while the air of a full car contained 10-7 parts. The outside air at the same time contained 44 parts. A series of tests made for the London County Council in 1902 showed that the air of the cars contained a minimum of 9 60 parts and a maximum of 147 parts. In some of the later tube railways in London-such as the Baker Street and Waterloo, and the Charing Cross and Hampstead lines-electrically driven exhaust fans are provided at about half-mile intervals; these each extract 18,500 cub. ft. of air per minute from the tunnels, and discharge it from the tops of the station roofs, fresh air being conveyed to the points of suction in the tunnels. The Boston system of electrically operated subways and tunnels is ventilated by electric fans capable of completely changing the air in each section about every fifteen minutes. Air admitted at portals and stations is withdrawn midway between stations. In the case of the East Boston tunnel, the air leaving the tunnel under the middle of the harbour is carried to the shore through longitudinal ducts (fig. 3) and is there expelled through fan-chambers. In the southerly 5 m. of the New York Rapid Transit railway, which runs in a four-track tunnel of rectangular section, having an area of 650 sq. ft., and built as close as possible to the surface of the streets, ventilation by natural means through the open staircases at the stations is mainly relied upon, with satisfactory results as regards the proportions of carbonic acid found in the air. But when intensely hot weather prevails in New York the tunnel air is sometimes 5 hotter still, due to the conversion of electrical energy into heat. This condition is aggravated by the fine diffusion through the air of oil from the motors, dust from the ballast and particles of metal ground off by the brake shoes, &c. Volume of Air Required for Ventilation. The consumption of coal by a locomotive during the passage through a tunnel having been ascertained, and 29 cub. ft. of poisonous gas being allowed for each pound of coal consumed, the volume of fresh air required to maintain the atmosphere of the tunnel at a standard of purity of 20 parts of carbon dioxide in 10,000 parts of air is ascertained as follows: The number of pounds of fuel consumed per mile, multiplied by 29, multiplied by 500, and divided by the interval in minutes between the trains, will give the volume of air in cubic feet which must be introduced into the tunnel per minute. As an illustration, assume that the tunnel is a mile in length, that the consumption of fuel is 32 lb per mile, and that one train passes through the tunnel every five minutes in each direction; then the volume of air required per minute will be 32 lb X 29 cub. ft. X 500-185,600 cub. st, 2 minutes. 1 m. 8 chains from east mouth 0-620=0·575 1.500-1.380 . I 520=1310 . 0·680=0·587 SEVERN TUNNEL (4 m. 284 chains in length). Down line, outside and quite clear of tunnel, Up line, outside and quite clear of tunnel, I in 100 3 m. 754 chains from Bristol mouth, gradient Ib per yard % per annum. 0-280-0240 .0 440-0.390 1200=1020 2.160 1.860 1900-1-630 0.310=0.270 At Newport mouth Down and up line under main-shaft level. 3200-2-750 It will be seen that the maximum wear and corrosion together reached the extraordinary weight of 2 lb per yard of rail per yeara very serious amount that involved great expenditure The wear occurred over the whole of the rail, but the top, over which the engine and train passed, wore at a greater rate, presumably on account of the surface being kept bright and the gases being able to act on it. The Great Western Company tried the experiment in the Severn tunnel of boxing up the rails, so that the ballast approached their surface within I in. or 1 in. It was found, however, that-in the case, at any rate, of the limestone ballastthe cure was almost worse than the disease, the result being a maximum wear of 2 tb and an average wear of just under 2 lb per yard of rail per year. The average on the open line would be about 0.25 lb in the same time. See Proc. Inst. Civ. Eng.; also works on tunnelling by Drinker, Simms, Stauffer and Prelini, and on tunnel shields, &c., by Copperthwaite. (H. A. C.) TUNNEL VAULT, the term in architecture given to the semicircular or elliptical vault over underground passages, in contradistinction to the wagon or barrel vault of edifices above ground. family of mackerels, belongs to the genus of which the bonito TUNNY (Thunnus thynnus), one of the largest fishes of the (Th. pelamys) and the albacores (Th. albacora, Th. alalonga, &c.) are equally well-known members. From the latter the tunny is distinguished by its much shorter pectoral fins, which reach backwards only to, or nearly to, the end of the first dorsal fin. It possesses nine short finlets behind the dorsal, and eight behind the anal fin. Its colour is dark bluish above, and greyish, tinged and spotted with silvery, below. The tunny is a pelagic fish, but periodically approaches the shore, wandering in large shoals, within well-ascertained areas along the coast. It not infrequently appears in small companies or singly in the English Channel and in the German Ocean, probably in pursuit Tunny. of the shoals of pilchards and herrings on which it feeds. The regularity of its appearance on certain parts of the coasts of the Mediterranean has led to the establishment of a systematic fishery, which has been carried on from the time of the Phoenicians to the present day. Immense numbers of tunnies were caught on the Spanish coast and in the Sea of Marmora, where, however, this industry has much declined. The Sardinian tunnies were considered to be of superior excellence. The greatest number is now caught on the north coast of Sicily, the fisheries of this island supplying most of the preserved tunny which is exported to other parts of the world. In ancient times the fish were preserved in salt, and that coming from Sardinia, which was specially esteemed by the Romans, was known as Salsamentum sardicum. At present preference is given to tunny | preserved in oil. Many of the fishes, especially the smaller ones, are consumed fresh. The tunny occurs also in the Pacific and is much sought for by anglers on the coast of southern California, where tuna-fishing has become a fashionable sport; but several other species seem to take its place in the Indo-Pacific ocean. It is one of the largest fishes, attaining to a length of ten ft. and to a weight of more than a thousand pounds. In connexion with the extremely active life of these fishes allusion should be made to the fact, first ascertained in 1839 by John (brother of Sir Humphry) Davy, that the temperature of the blood of a tunny may be considerably higher than that of the surrounding water, a discovery which disposed of the timehonoured division of vertebrate animals into warm-blooded and cold-blooded.. The variations and movements of the tunny and albacores were studied with special care by King Carlos of Portugal, who published in 1899 a large illustrated memoir entitled A Pesca do atum no Algarve in 1898 (Lisbon). This memoir is accompanied by excellent figures of the different species of Thunnus and charts of their distribution in the Atlantic. TUNSTALL (or TONSTALL), CUTHBERT (1474-1559), English prelate, was an illegitimate son of Thomas Tunstall of Thurland Castle, Lancashire, his legitimate half-brother, Brian Tunstall, being killed at Flodden in 1513. Cuthbert seems to have studied at Oxford, at Cambridge and at Padua, and he became a distinguished scholar, winning favourable comment from Erasmus. Having held several livings in quick succession, he became chancellor to William Warham, archbishop of Canterbury, in 1511, and he was soon employed on diplomatic business by Henry VIII. and Wolsey, being sent to Brussels in 1515 and to Cologne in 1519, while he was at Worms during the famous Diet of 1521. In 1516 he had been made master of the rolls; in 1521 he became dean of Salisbury, in 1522 bishop of London, and in 1523 keeper of the privy seal. For Henry VIII. he negotiated with Charles V. after his victory at Pavia in 1525 and he helped to arrange the Peace of Cambrai in 1529. In 1530 he succeeded Wolsey as bishop of Durham. Tunstall's religious views now gave some anxiety. He adhered firmly to the traditional teaching of the Church, but after some slight hesitation he accepted Henry as its head and publicly defended this position. In 1537 the bishop was appointed president of the new council of the north, but although he was often engaged in treating with the Scots he found time to take part in other public business and to attend parliament, where in 1539 he participated in the discussion on the bill of six articles. Although he disliked the religious policy pursued by the advisers of Edward VI. and voted against the first act of uniformity in 1549, he continued to discharge his public duties without molestation until after the fall of the protector Somerset; then in May 1551, he was placed in custody. A biil charging him with treason was introduced, but the House of Commons refused to pass it; he was, however, deprived of his bishopric in October 1552. On the accession of Mary in 1553 he was released and was again bishop of Durham, but during this reign he showed no animus against the Protestants. When Elizabeth came to the throne he refused to take the oath of supremacy, and he would not help to consecrate Matthew Parker as archbishop of Canterbury. He was arrested, and was still a prisoner at Lambeth when he died on the 18th of November 1559 Among Tunstall's writings are De veritate corporis et sanguinis domini nostri Jesu Christi in eucharistia (1554); and De arte suppulandi libri quattuor (1522). The bishop's correspondence as president of the council of the north is in the British Museum. TUNSTALL, a market town of Staffordshire, England, on the northern outskirts of the Potteries district, included in the parliamentary borough of Newcastle-under-Lyme, 4 m. N.W. from Stoke-upon-Trent by the North Staffordshire railway. Pop. of urban district (1901), 19,492. The town is of modern growth. The Victoria Institute (1889) includes a library and schools of art and science. The neighbourhood is full of collieries, ironworks and potteries. Kidsgrove, Chatterley and Talk-o'-th'hill are large neighbouring villages; the mines at the last-named were the scene of a terrible explosion in 1866, by which nearly a hundred lives were lost. There are brick and tile works in Tunstall. The town is included in the large parish of Wolstanton, and in the borough of Stoke-on-Trent (q.v.) under the " Potteries Federation "scheme (1908). TUPIS (Comrades), a tribe and stock of South American Indians of Brazil. They call all other peoples Tapuyas (foreigners). Their original home is believed to have been on the Amazon, and from its mouth they spread far southwards along the Brazilian coast. When hard pressed by the Portuguese they retreated to the Andes. Martius gives the Tupi nation a wide range, from the Atlantic to the Andes, and from Paraguay to the Amazon. Of this stock are the Omaguas, Cocomas and other Peruvian tribes. Latham makes the Tupis members of the Guarani stock. The "Lingoa Geral" or trade language between Portuguese and Amazon Indians is a corruption of the Tupi tongue. TUPPER, SIR CHARLES, BART. (1821- ), British colonial statesman, son of the Rev. Charles Tupper, D.D., was born at Amherst, Nova Scotia, on the 2nd of July 1821, and was educated at Horton Academy. He afterwards studied for the medical profession at Edinburgh University, where he received the diplomas of M.D. and L.R.C.S. In 1855 he was returned to the Nova Scotia Assembly for Cumberland county. In 1862 he was appointed, by act of parliament, governor of Dalhousie College, Halifax; and from 1867 till 1870 he was president of the Canadian Medical Association. Mr Tupper was a member of the executive council and provincial secretary of Nova Scotia from 1857 to 1860, and from 1863 to 1867. He became prime minister of Nova Scotia in 1864, and held that office until the Union Act came into force on the 1st of July 1867, when his government retired. He was a delegate to Great Britain on public business from the Nova Scotia government in 1858 and 1865, and from the Dominion government in March 1868. Mr Tupper was leader of the delegation from Nova Scotia to the Union conference at Charlottetown in 1864, and to that of Quebec during the same year; and to the final colonial conference in London, which assembled to complete the terms of union, in 1866-1867. On that occasion he received a patent of rank and precedence from Queen Victoria as an executive councillor of Nova Scotia. He was sworn a member of the privy council of Canada, June 1870, and was president of that body from that date until the 1st of July 1872, when he was appointed minister of inland revenue. This office he held until February 1873, when he became minister of customs under Sir John Macdonald, resigning with the ministry at the close of 1873. On Sir John's return to power in 1878, Mr Tupper became minister of public works, and in the following year minister of railways and canals. At this time he was made K.C.M.G. Mr Tupper was the author of the Public Schools Act of Nova Scotia, and had been largely instrumental in moulding the Dominion Confederation Bill and other important measures. Sir Charles represented the county of Cumberland, Nova Scotia, for thirty-two years in successionfirst in the Nova Scotia Assembly, and subsequently in the Dominion parliament until 1884, when he resigned his seat on being appointed high commissioner for Canada in London. Shortly before the Canadian Federal elections of February 1887, Sir Charles re-entered the Conservative cabinet as finance minister. By his efforts the Canadian Pacific railway was enabled to float a loan of $30,000,000, on the strength of which the line was finished several years before the expiration of the contract time. He resigned the office of finance minister in May 1888, when he was reappointed high commissioner for the Dominion of Canada in London. Sir Charles was designated one of the British plenipotentiaries to the Fisheries Convention at Washington in 1887, the result of which conference was the signing of a treaty in February 1888 (rejected by the U.S. Senate) for the settlement of the matters in dispute between Canada and the United States in connexion with the Atlantic fisheries. He was created a baronet in September 1888. When the Dominion cabinet, under Sir Mackenzie Bowell, was reconstituted in January 1896 Sir Charles Tupper accepted office, and in the following April be |