Part 18

In the automatic vacuum-brake, the exhausting apparatus generally consists of a combined large and small ejector (a form of jet-pump) worked by steam and under the control of the driver, though sometimes a mechanical air-pump, driven from the crosshead of the locomotive, is substituted for the small ejector. These ejectors, of which the small one is at work continuously while the large one is only employed when it is necessary to create vacuum quickly, e.g. to take off the brakes after a short stop, produce in the train-pipe a vacuum equal to about 20 in. of mercury, or in other words reduce the pressure within it to about one-third of an atmosphere. The train-pipe extends the whole length of the train and communicates under each vehicle with a cylinder, to the piston of which, by suitable rods and levers, the brake-shoes are connected. The communication between the train-pipe and the cylinder is controlled by a ball-valve, one form of which is shown in fig. 2. The release-valve is for the purpose of withdrawing the ball from its seat when it is necessary to take off the brakes by hand; it is made air-tight by a small diaphragm, the pressure of which, when there is vacuum in the pipe, pulls in the spindle and allows the ball to fall freely into its seat. When air is exhausted through the train-pipe it travels out from below the piston direct, and from above it past the ball, which is thus forced off its seat, to roll back again when the exhaustion is complete. In this state of affairs the piston is held in equilibrium and the brake-blocks are free of the wheels. To apply them, air is admitted to the train-pipe, either purposely by the guard or driver, or accidentally by the rupture of the train-pipe or coupling-hose between the vehicles. The air passes to the lower side of the piston, but is prevented from gaining access to the upper side by the ball-valve which blocks the passage; hence the pressure becomes different on the two sides of the piston, which in consequence is forced upwards and thus applies the brakes. They are released by the re-establishment of equilibrium (by the use of the large ejector if necessary); when this is done the piston falls and the brakes drop off. The general arrangement of the apparatus is shown in fig. 2. To render the application of the brakes nearly simultaneous throughout a long train, the valve in the guard's van is arranged to open automatically when the driver suddenly lets in air to the train-pipe. This valve has a small hole through its stem, and is secured at the top by a diaphragm to a small dome-like chamber, which is exhausted when a vacuum is created in the train-pipe. A gradual application destroys the vacuum in the chamber as quickly as in the pipe and the diaphragm remains unmoved; but with a sudden one the vacuum below the valve is destroyed more quickly, and with the difference of pressure the diaphragm lifts the valve and admits air. A rapid-acting valve (fig. 3) is sometimes interposed between the train-pipe and the cylinder on each vehicle. In the normal or running position, a vacuum is maintained below the valve A and above the diaphragm B, while the chamber below B and above A is at atmospheric pressure. For an emergency application of the brake, air is suddenly admitted to the train-pipe and thus to the lower side of A, and the pressure acting on the under side of B is sufficient to cause it to lift the valve A, and to admit air from the atmosphere, both to the brake-cylinder and the train-pipe, through the clappet-valve D, which also rises because of the difference of pressure on its two sides. In a graduated application, neither D nor A rises from its seat, but air from the train-pipe finds access to the brake-cylinder by passing around the peg C, which is so proportioned as to allow the necessary amount of air to enter the brake-cylinder, and so obtain simultaneous

## action of the brake throughout the train. When the handle E is turned

so as to prevent the clappet D from rising, the rapid action is cut out and the brake acts as an ordinary vacuum automatic brake. A modification of the device for obtaining accelerated action, described above in connexion with the Westinghouse brake, is also applicable. Accelerating chambers, again containing air at atmospheric pressure, are provided on each vehicle and are connected with the train-pipe by valves which open as the vacuum in the latter begins to decrease with the operation of the driver's valve. The air thus admitted into the train-pipe effects a still further local reduction of the vacuum, which is sufficient to actuate the accelerating valve of each next succeeding vehicle and is thus rapidly propagated throughout the train.

Brake trials.

Famous tests of railway brakes were those made by Sir Douglas Galton and Mr George Westinghouse on the London, Brighton and South Coast railway, in England, in 1878, and by a committee of the Master Car Builders' Association, near Burlington, Iowa, in 1886 and 1887. The object of the former series (for accounts of which see _Proc. Inst. Mech. Eng._, 1878, 1879) was to determine the co-efficient of friction between the brake-shoe and the wheel, and between the wheel and rail at different velocities when the wheels were revolving and when skidded, i.e. stopped in their rotation and caused to slide. These experiments were the first of their kind ever undertaken, and for many years their results furnished most of the trustworthy data obtainable on the friction of motion. It was found that the co-efficient of friction between cast-iron shoes and steel-tired wheels increased as the speed of the train decreased, varying from 0.111 at 55 m. an hour to 0.33 when the train was just moving. It also decreased with the time during which the brakes were applied; thus at 20 m. an hour the co-efficient was at the beginning 0.182, after ten seconds 0.133, after twenty seconds 0.099. Generally speaking, especially at moderate speeds, the decrease in the co-efficient of friction due to time is less than the increase due to decrease of speed, although when the time is long the reverse may be true. When the wheels are skidded the retardation of the train is always reduced; therefore, for the greatest braking effect, the pressures on the brake-shoes should never be sufficient to cause the wheels to slide on the rails. The Burlington brake tests were undertaken to determine the practicability of using power brakes on long and heavy freight trains. In the 1886 tests there were five competitors--three buffer-brakes, one compressed-air brake, and one vacuum-brake. The tests comprised stops with trains of twenty-five and fifty vehicles, at 20 and 40 m. an hour, on the level and on gradients of 1 in 100. They demonstrated that the buffer-brakes were inadequate for long trains, and that considerable improvements in the continuous brakes, both compressed-air and vacuum, would be needed to make them act quickly enough to avoid excessive shocks in the rear vehicles. In 1887 the trials of the year before were repeated by the same committee, and at the same place. Trains of fifty vehicles, about 2000 ft. long and fitted with each brake, were again provided, and there were again five competitors, but they all entered continuous brakes--three compressed-air brakes, one vacuum and one electric. The results of the first day's test of the train equipped with Westinghouse brakes are shown in Table I., the distances in which are the feet run by the train after the brakes were set, and the times the seconds that elapsed from the application of the brakes to full stop.

[Illustration: FIG. 3--Rapid-acting Vacuum-Brake Valve.]

TABLE I.--_Stops of a Train of Fifty Empty Cars, 1887--Automatic Air-Brakes._

+-----------+----------+----------+---------------------+ | Speed in | Distance | Time in | Equivalent Distance | | Miles per | in Feet. | Seconds. | at 20 m. and 40 m. | | Hour. | | | | +-----------+----------+----------+----------+----------+ | 19-1/2 | 186 | 9-3/4 | 196 | . . | | 19-1/4 | 215 | 11 | 233 | . . | | 36-1/2 | 588 | 17 | . . | 693 | +-----------+----------+----------+----------+----------+

The remarkable shortness of these stops is the more evident when they are compared with the best results obtained in 1886, as shown in Table II.

TABLE II.--_Stops of a Train of Fifty Empty Cars, 1886--Automatic Air-Brakes._

+-----------+----------+----------+---------------------+ | Speed in | Distance | Time in | Equivalent Distance | | Miles. | in Feet. | Seconds. | at 20 m. and 40 m. | +-----------+----------+----------+----------+----------+ | 23.5 | 424 | 17-1/2 | 307 | . . | | 20.3 | 354 | 16 | 340 | . . | | 40 | 922 | 22-1/2 | . . | 922 | | 40 | 927 | 22-3/4 | . . | 927 | +-----------+----------+----------+----------+----------+

The time that elapsed between the application of the brakes on the engine and on the fiftieth vehicle was almost twice as great in 1886 as in 1887, being in the latter tests only five to six seconds, and in 1887 the stops were made in less than two-thirds the distance required in 1886. Still, violent shocks were caused by the rear vehicles running against those in front, before the brakes on the former were applied with sufficient force to hold them, and these shocks were so severe as to make the use of the brakes in practice impossible on long trains. When the triple-valves were actuated electrically, however, the stops were still further improved, as shown in Table III.

Table III.--_Stops of a Train of Fifty Empty Cars--Electric Application of Air-Brakes._

+-----------+----------+----------+---------------------+ | Speed in | Distance | Time in | Equivalent Distance | | Miles. | in Feet. | Seconds. | at 20 m. and 40 m. | +-----------+----------+----------+----------+----------+ | 21-1/2 | 160 | 7 | 139 | . . | | 23 | 183 | 8 | 138 | . . | | 38 | 475 | 14-1/2 | . . | 519 | | 36-1/2 | 460 | 14 | . . | 545 | +-----------+----------+----------+----------+----------+

Although the same levers, shoes, rods and other connexions were used, there were no shocks in the fiftieth car of the train on any stop, whether on the level or on a gradient. The committee in charge reported that the best type of brake for long freight trains was one operated by air, in which the valves were actuated by electricity, but they expressed doubt of the practicability of using electricity on freight trains. The Westinghouse Company then proceeded to quicken the

## action of the triple-valve, operated by air only, so that stops with

fifty-car trains could be made without shock, and without electrically operated valves; and they were so successful in this respect that, towards the end of the same year, 1887, with a train of fifty vehicles, stops were made without shock, fully equalling in quickness and shortness of distance run any that had been made at the trials by the electrically operated brakes.

In 1889 some further tests were made by Sir Douglas Galton with the automatic vacuum-brake, on a practically level portion of the Manchester, Sheffield & Lincolnshire railway (now the Great Central). The train was composed of an engine, tender and forty carriages, the total length over buffers being 1464 ft., and the total weight 574 tons, of which 423 tons were braked. At a speed of about 32 m. an hour this train was brought to a standstill in twelve seconds after the application of the brakes, in a distance of 342 ft.

BRAKELOND, JOCELYN DE (fl. 1200), English monk, and author of a chronicle narrating the fortunes of the monastery of Bury St Edmunds between 1173 and 1202. He is only known to us through his own work. He was a native of Bury St Edmunds; he served his novitiate under Samson of Tottington, who was at that time master of the novices, but afterwards sub-sacrist, and, from 1182, abbot of the house. Jocelyn took the habit of religion in 1173, during the time of Abbot Hugo (1157-1180), through whose improvidence and laxity the abbey had become impoverished and the inmates dead to all respect for discipline. The fortunes of the abbey changed for the better with the election of Samson as Hugo's successor. Jocelyn, who became abbot's chaplain within four months of the election, describes the administration of Samson at considerable length. He tells us that he was with Samson night and day for six years; the picture which he gives of his master, although coloured by enthusiastic admiration, is singularly frank and intimate. It is all the more convincing since Jocelyn is no stylist. His Latin is familiar and easy, but the reverse of classical. He thinks and writes as one whose interests are wrapped up in his house; and the unique interest of his work lies in the minuteness with which it describes the policy of a monastic administrator who was in his own day considered as a model.

Jocelyn has also been credited with an extant but unprinted tract on the election of Abbot Hugo (Harleian MS. 1005, fo. 165); from internal evidence this appears to be an error. He mentions a (non-extant) work which he wrote, before the _Cronica_, on the miracles of St Robert, a boy whom the Jews of Bury St Edmunds were alleged to have murdered (1181).

See the editions of the _Cronica Jocelini de Brakelonda_ by T. Arnold (in _Memorials of St Edmund's Abbey_, vol. i. Rolls series, 1890), and by J.G. Rokewood (Camden Society, 1840); also Carlyle's _Past and Present_, book ii. A translation and notes are given in T.E. Tomlin's _Monastic and Social Life in the Twelfth Century in the Chronicle of Jocelyn de Brakelond_ (1844). There is also a translation of Jocelyn by Sir E. Clarke (1907).

BRAMAH, JOSEPH (1748-1814), English engineer and inventor, was the son of a farmer, and was born at Stainborough, Yorkshire, on the 13th of April 1748. Incapacitated for agricultural labour by an accident to his ankle, on the expiry of his indentures he worked as a cabinet-maker in London, where he subsequently started business on his own account. His first patent for some improvements in the mechanism of water-closets was taken out in 1778. In 1784 he patented the lock known by his name, and in 1795 he invented the hydraulic press. For an important part of this, the collar which secured water-tightness between the plunger and the cylinder in which it worked, he was indebted to Henry Maudslay, one of his workmen, who also helped him in designing machines for the manufacture of his locks. In 1806 he devised for the Bank of England a numerical printing machine, specially adapted for bank-notes. Other inventions of his included the beer-engine for drawing beer, machinery for making aerated waters, planing machines, and improvements in steam-engines and boilers and in paper-making machinery. In 1785 he suggested the possibility of screw propulsion for ships, and in 1802 the hydraulic transmission of power; and he constructed waterworks at Norwich in 1790 and 1793. He died in London on the 9th of December 1814.

BRAMANTE, or BRAMANTE LAZZARI (c. 1444-1514), Italian architect and painter, whose real name was Donate d'Augnolo, was born at Monte-Asdrualdo in Urbino, in July 1444. He showed a great taste for drawing, and was at an early age placed under Fra Bartolommeo, called Fra Carnavale. But though he afterwards gained some fame as a painter, his attention was soon absorbed by architecture. He appears to have studied under Scirro Scirri, an architect in his native place, and perhaps under other masters. He then set out from Urbino, and proceeded through several of the towns of Lombardy, executing works of various magnitudes, and examining patiently all remains of ancient art. At last, attracted by the fame of the great Duomo, he reached Milan, where he remained from 1476 to 1499. He seems to have left Milan for Rome about 1500. He painted some frescoes at Rome, and devoted himself to the study of the ancient buildings, both in the city and as far south as Naples. About this time the Cardinal Caraffa commissioned him to rebuild the cloister of the Convent della Pace. Owing to the celerity and skill with which Bramante did this, the cardinal introduced him to Pope Alexander VI. He began to be consulted on nearly all the great architectural operations in Rome, and executed for the pope the palace of the Cancelleria or chancery. Under Julius II., Alexander's successor, Bramante's talents began to obtain adequate sphere of exercise. His first large work was to unite the straggling buildings of the palace and the Belvedere. This he accomplished by means of two long galleries or corridors enclosing a court. The design was only in part completed before the death of Julius and of the architect. So impatient was the pope and so eager was Bramante, that the foundations were not sufficiently well attended to; great part of it had, therefore, soon to be rebuilt, and the whole is now so much altered that it is hardly possible to decipher the original design.

Besides executing numerous smaller works at Rome and Bologna, among which is specially mentioned by older writers a round temple in the cloister of San Pietro-a-Montorio, Bramante was called upon by Pope Julius to take the first part in one of the greatest architectural enterprises ever attempted--the rebuilding of St Peter's. Bramante's designs were complete, and he pushed on the work so fast that before his death he had erected the four great piers and their arches, and completed the cornice and the vaulting in of this portion. He also vaulted in the principal chapel. After his death on the 11th of March 1514, his design was much altered, in particular by Michelangelo.

See Pungileoni, _Memoire intorno alla vita ed alle opere di Bramante_ (Rome, 1836); H. Semper, _Donato Bramante_ (Leipzig, 1879).

BRAMPTON, HENRY HAWKINS, BARON (1817-1907), English judge, was born at Hitchin, on the 14th of September 1817. He received his education at Bedford school. The son of a solicitor, he was early familiarized with legal principles. Called to the bar at the Middle Temple in 1843, he at once joined the old home circuit, and after enjoying a lucrative practice as a junior, took silk in 1859. His name is identified with many of the famous trials of the reign of Queen Victoria. He was engaged in the Simon Bernard case (of the Orsini plot celebrity), in that of _Roupell_ v. _Waite_, and in the Overend-Gurney prosecutions. The two _causes celebres_, however, in which Hawkins attained his highest legal distinction were the Tichborne trials and the great will case of _Sugden_ v. _Lord St Leonards_. In both of these he was victorious. In the first his masterly cross-examination of the witness Baigent was one of the great features of the trial. He did a lucrative business in references and arbitrations, and acted for the royal commissioners in the purchase of the site for the new law courts. Election petitions also formed another branch of his extensive practice. Hawkins was raised to the bench in 1876, and was assigned to the then exchequer division of the High Court, not as baron (an appellation which was being abolished by the Judicature Act), but with the title of Sir Henry Hawkins. He was a great advocate rather than a great lawyer. His searching voice, his manner, and the variety of his facial expression, gave him an enormous influence with juries, and as a cross-examiner he was seldom, if ever, surpassed. He was an excellent judge in chambers, where he displayed a clear and vigorous grasp of details and questions of fact. His knowledge of the criminal law was extensive and intimate, the reputation he gained as a "hanging" judge making him a terror to evil-doers; and the court for crown cases reserved was never considered complete without his assistance. In 1898 he retired from the bench, and was raised to the peerage under the title of Baron Brampton. He frequently took part in determining House of Lords appeals, and his judgments were distinguished by their lucidity and grasp. He held for many years the office of counsel to the Jockey Club, and as an active member of that body found relaxation from his legal and judicial duties at the leading race meetings, and was considered a capable judge of horses. In 1898 he was received into the Roman Catholic Church, and in 1903 he presented, in conjunction with Lady Brampton (his second wife), the chapel of SS. Augustine and Gregory to the Roman Catholic cathedral of Westminster, which was consecrated in that year. In 1904 he published his _Reminiscences_. He died in London on the 6th of October 1907, and Lady Brampton in the following year.

BRAMPTON, a market town in the Eskdale parliamentary division of Cumberland, England, 9 m. E.N.E. of Carlisle, on a branch of the North Eastern railway. Pop. (1901) 2494. It is picturesquely situated in a narrow valley opening upon that of the Irthing. The town has an agricultural trade, breweries, and manufactures of cotton and tweeds. The neighbourhood is rich in historical associations. Two miles N.E. of Brampton is the castle of Naworth, a fine example of a Border fortress. It was built in the reign of Edward III., by a member of the family of Dacre, who for many generations had had their stronghold here. Overlooking a deep wooded ravine, with streams to the east and west, the great quadrangular castle was naturally defended except on the south, where it was rendered secure by a double moat and drawbridge. By marriage in 1577 with Lady Elizabeth Dacre it passed into the hands of William Howard, afterwards lord warden of the Marches, the "Belted Will" of Sir Walter Scott and the Border ballads, who acquired great fame by his victories over the Scottish moss-troopers. The castle, the walls of which have many secret passages and hiding-places, is inhabited, and in its hall are numerous fine pictures, including a portrait of Charles I. by Van Dyck. Not far distant is Lanercost Priory, where in 1169 an Augustinian monastery was established. In 1311 Robert Bruce and his army were quartered here, and the priory was pillaged in 1346 by David, king of Scotland. From this time its prosperity declined, and at its dissolution under Henry VIII. it consisted only of a prior and seven canons. The Early English church has a restored nave, but retains much fine carving. The chancel is ruined, but the interesting crypt is preserved.