Part 8

BOILEAU-DESPREAUX, NICOLAS (1636-1711), French poet and critic, was born on the 1st of November 1636 in the rue de Jerusalem, Paris. The same Despreaux was derived from a small property at Crosne near Villeneuve Saint-Georges. He was the fifteenth child of Gilles Boileau, a clerk in the parlement. Two of his brothers attained some distinction: Gilles Boileau (1631-1669), the author of a translation of Epictetus; and Jacques Boileau, who became a canon of the Sainte-Chapelle, and made valuable contributions to church history. His mother died when he was two years old; and Nicolas Boileau, who had a delicate constitution, seems to have suffered something from want of care. Sainte-Beuve puts down his somewhat hard and unsympathetic outlook quite as much to the uninspiring circumstances of these days as to the general character of his time. He cannot be said to have been early disenchanted, for he never seems to have had any illusions; he grew up with a single passion, "the hatred of stupid books." He was educated at the College de Beauvais, and was then sent to study theology at the Sorbonne. He exchanged theology for law, however, and was called to the bar on the 4th of December 1656. From the profession of law, after a short trial, he recoiled in disgust, complaining bitterly of the amount of chicanery which passed under the name of law and justice. His father died in 1657, leaving him a small fortune, and thenceforward he devoted himself to letters.

Such of his early poems as have been preserved hardly contain the promise of what he ultimately became. The first piece in which his peculiar powers were displayed was the first satire (1660), in imitation of the third satire of Juvenal; it embodied the farewell of a poet to the city of Paris. This was quickly followed by eight others, and the number was at a later period increased to twelve. A twofold interest attaches to the satires. In the first place the author skilfully parodies and attacks writers who at the time were placed in the very first rank, such as Jean Chapelain, the abbe Charles Cotin, Philippe Quinault and Georges de Scudery; he openly raised the standard of revolt against the older poets. But in the second place he showed both by precept and practice what were the poetical capabilities of the French language. Prose in the hands of such writers as Descartes and Pascal had proved itself a flexible and powerful instrument of expression, with a distinct mechanism and form. But except with Malherbe, there had been no attempt to fashion French versification according to rule or method. In Boileau for the first time appeared terseness and vigour of expression, with perfect regularity of verse structure. His admiration for Moliere found expression in the stanzas addressed to him (1663), and in the second satire (1664). In 1664 he composed his prose _Dialogue des heros de roman_, a satire on the elaborate romances of the time, which may be said to have once for all abolished the lucubrations of La Calprenede, Mlle de Scudery and their fellows. Though fairly widely read in manuscript, the book was not published till 1713, out of regard, it is said, for Mlle de Scudery. To these early days belong the reunions at the _Moulon Blanc_ and the _Pomme du Pin_, where Boileau, Moliere, Racine, Chapelle and Antoine Furetiere met to discuss literary questions. To Moliere and Racine he proved a constant friend, and supported their interests on many occasions.

In 1666, prompted by the publication of two unauthorized editions, he published _Satires du Sieur D...._, containing seven satires and the _Discours au roi_. From 1669 onwards appeared his epistles, graver in tone than the satires, maturer in thought, more exquisite and polished in style. The _Epitres_ gained for him the favour of Louis XIV., who desired his presence at court. The king asked him which he thought his best verses. Whereupon Boileau diplomatically selected as his "least bad" some still unprinted lines in honour of the grand monarch and proceeded to recite them. He received forthwith a pension of 2000 livres. In 1674 his two masterpieces, _L'Art poetique_ and _Le Lutrin_, were published with some earlier works as the _Oeuvres diverses du sieur D_.... The first, in imitation of the _Ars Poetica_ of Horace, lays down the code for all future French verse, and may be said to fill in French literature a parallel place to that held by its prototype in Latin. On English literature the maxims of Boileau, through the translation revised by Dryden, and through the magnificent imitation of them in Pope's _Essay on Criticism_, have exercised no slight influence. Boileau does not merely lay down rules for the language of poetry, but analyses carefully the various kinds of verse composition, and enunciates the principles peculiar to each. Of the four books of _L'Art poetique_, the first and last consist of general precepts, inculcating mainly the great rule of _bon sens_; the second treats of the pastoral, the elegy, the ode, the epigram and satire; and the third of tragic and epic poetry. Though the rules laid down are of value, their tendency is rather to hamper and render too mechanical the efforts of poetry. Boileau himself, a great, though by no means infallible critic in verse, cannot be considered a great poet. He rendered the utmost service in destroying the exaggerated reputations of the mediocrities of his time, but his judgment was sometimes at fault. The _Lutrin_, a mock heroic poem, of which four cantos appeared in 1674, furnished Alexander Pope with a model for the _Rape of the Lock_, but the English poem is superior in richness of imagination and subtlety of invention. The fifth and sixth cantos, afterwards added by Boileau, rather detract from the beauty of the poem; the last canto in particular is quite unworthy of his genius. In 1674 appeared also his translation of Longinus _On the Sublime_, to which were added in 1693 certain critical reflections, chiefly directed against the theory of the superiority of the moderns over the ancients as advanced by Charles Perrault.

Boileau was made historiographer to the king in 1677. From this time the amount of his production diminished. To this period of his life belong the satire, _Sur les femmes_, the ode, _Sur la prise de Namur_, the epistles, _A mes vers_ and _Sur l'amour de Dieu_, and the satire _Sur l'homme_. The satires had raised up a crowd of enemies against Boileau. The 10th satire, on women, provoked an _Apologie des femmes_ from Charles Perrault. Antoine Arnauld in the year of his death wrote a letter in defence of Boileau, but when at the desire of his friends he submitted his reply to Bossuet, the bishop pronounced all satire to be incompatible with the spirit of Christianity, and the 10th satire to be subversive of morality. The friends of Arnauld had declared that it was inconsistent with the dignity of a churchman to write on any subject so trivial as poetry. The epistle, _Sur l'amour de Dieu_, was a triumphant vindication on the part of Boileau of the dignity of his art. It was not until the 15th of April 1684 that he was admitted to the Academy, and then only by the king's wish. In 1687 he retired to a country-house he had bought at Auteuil, which Racine, because of the numerous guests, calls his _hotellerie d'Auteuil_. In 1705 he sold his house and returned to Paris, where he lived with his confessor in the cloisters of Notre Dame. In the 12th satire, _Sur l'equivoque_, he attacked the Jesuits in verses which Sainte-Beuve called a recapitulation of the _Lettres provinciales_ of Pascal. This was written about 1705. He then gave his attention to the arrangement of a complete and definitive edition of his works. But the Jesuit fathers obtained from Louis XIV. the withdrawal of the privilege already granted for the publication, and demanded the suppression of the 12th satire. These annoyances are said to have hastened his death, which took place on the 13th of March 1711.

Boileau was a man of warm and kindly feelings, honest, outspoken and benevolent. Many anecdotes are told of his frankness of speech at court, and of his generous actions. He holds a well-defined place in French literature, as the first who reduced its versification to rule, and taught the value of workmanship for its own sake. His influence on English literature, through Pope and his contemporaries, was not less strong, though less durable. After much undue depreciation Boileau's critical work has been rehabilitated by recent writers, perhaps to the extent of some exaggeration in the other direction. It has been shown that in spite of undue harshness in individual cases most of his criticisms have been substantially adopted by his successors.

Numerous editions of Boileau's works were published during his lifetime. The last of these, _Oeuvres diverses_ (1701), known as the "favourite" edition of the poet, was reprinted with variants and notes by Alphonse Pauly (2 vols., 1894). The critical text of his works was established by Berriat Saint-Prix, _Oeuvres de Boileau_ (4 vols., 1830-1837), who made use of some 350 editions. This text, edited with notes by Paul Cheron, with the _Boloeana_ of 1740, and an essay by Sainte-Beuve, was reprinted by Garnier _freres_ (1860).

See also Sainte-Beuve, _Causeries du lundi_, vol. vi.; F. Brunetiere, "L'Esthetique de Boileau" (_Revue des Deux Mondes_, June 1889), and an exhaustive article by the same critic in _La Grande encyclopedie_; G. Lanson, _Boileau_ (1892), in the series of _Grands ecrivains francais_.

BOILER, a vessel in which water or other liquid is heated to the boiling point; specifically, the apparatus by which steam is produced from water, as one step in the process whereby the potential energy of coal or other fuel is converted into mechanical work by means of the steam-engine. Boilers of the latter kind must all possess certain essential features, whilst of other qualities that are desirable some may not be altogether compatible with the special conditions under which the boilers are to be worked. Amongst the essentials are a receptacle capable of containing the water and the steam produced by its evaporation, and strong enough continuously to withstand with safety the highest pressure of steam for which the boiler is intended. Another essential is a furnace for burning the fuel, and a further one is the provision of a sufficiency of heating surface for the transmission of the heat produced by the combustion of the fuel to the water which is required to be evaporated. Desirable qualities are that the arrangements of the furnaces should be such that a reasonably perfect combustion of the fuel should be possible, and that the heating surfaces should be capable of transmitting a large proportion of the heat produced to the water so as to obtain a high evaporative efficiency. Further, the design generally should be compact, not too heavy or costly, and such that the cleaning necessary to maintain the evaporative efficiency can be easily effected. It should also be such that the cost of upkeep will be small, and that only an average amount of skill and attention will be required under working conditions. It is for providing these qualities in different degrees according to the special requirements of various circumstances that the very different designs of the various types of boilers have been evolved.

_Classes of Boilers._--Boilers generally may be divided into two distinct classes, one comprising those which are generally called "tank" boilers, containing relatively large quantities of water, and the other those which are generally called "water-tube" boilers, in which the water is mainly contained in numerous comparatively small tubes. There are, however, some types of boiler which combine to some extent the properties of both these classes. Each class has its representatives amongst both land and marine boilers. In "tank" boilers the outer shell is wholly or partially cylindrical, this form being one in which the necessary strength can be obtained without the use of a large number of stays. The boilers are generally internally fired, the furnace plates being surrounded with water and forming the most efficient portion of the heating surfaces. On leaving the furnace the products of combustion are led into a chamber and thence through flues or through numerous small tubes which serve to transmit some of the heat of combustion to the water contained in the boiler. In "water-tube" boilers the fire is usually placed under a collection of tubes containing water and forming the major portion of the heating surface of the boiler. Both the fire and the tubes are enclosed in an outer casing of brickwork or other fire-resisting substance. In some forms of water-tube boiler the fire is entirely surrounded by water-tubes and the casing is in no part exposed to the direct action of the fire. In "tank" boilers generally no difficulty is experienced in keeping all the heating surfaces in close contact with water, but in "water-tube" boilers special provision has to be made in the design for maintaining the circulation of water through the tubes. (For "flash" boilers see MOTOR VEHICLES, and for domestic hot-water boilers HEATING.)

Lancashire.

_Tank Boilers._--Of large stationary boilers the forms most commonly used are those known as the "Lancashire" boiler, and its modification the "Galloway" boiler. These boilers are made from 26 to 30 ft. long, with diameters from 6-1/2 to 8 ft., and have two cylindrical furnace flues which in the "Lancashire" boiler extend for its whole length (see fig. 3). The working pressure is about 60 lb. per sq. in. in the older boilers, from 100 lb. to 120 lb. per sq. in. in those supplying steam to compound engines, and from 150 to 170 lb. where triple expansion engines are used. In some cases they have been constructed for a pressure of 200 lb. per sq. in. The furnace flues are usually made in sections from 3 to 3-1/2 ft. long. Each section consists of one plate bent into a cylindrical form, the longitudinal joint being welded, and is flanged at both ends, the various pieces being joined together by an "Adamson" joint (fig. 1.). It will be seen that these joints do not expose either rivets or double thickness of plate to the

## action of the fire; they further serve as stiffening rings to prevent

collapse of the flue. In most of these boilers the heating surface is increased by fitting in the furnace flues a number of "Galloway" tubes. These are conical tubes, made with a flange at each end, by means of which they are connected to the furnace plate. They are so proportioned that the diameter of the large end of the tube is slightly greater than that of the flange of the small end; this enables them to be readily removed and replaced if necessary. These tubes not only add to the heating surface, but they stiffen the flue, promote circulation of the water in the boiler, and by mixing up the flue gases improve the evaporative efficiency.

[Illustration: FIG. 1.--Adamson Joint.]

In the "Galloway" boiler the two furnaces extend only for about 9 or 10 ft. into the boiler, and lead into a large chamber or flue in which a number of "Galloway" tubes are fitted, and which extends from the furnace end to the end of the boiler. A cross section of this flue showing the distribution of the Galloway tubes is shown in fig. 2. When boilers less than about 6-1/2 ft. in diameter are needed, a somewhat similar type to the Lancashire boiler is used containing only one furnace. This is called a "Cornish" boiler.

[Illustration: FIG. 2.--Galloway Boiler: Section beyond the Bridge.]

In all three types of boiler the brickwork is constructed to form one central flue passing along the bottom of the boiler and two side flues extending up the side nearly to the water-level. A cross section of the brickwork is shown in fig. 2. The usual arrangement is for the flue gases to be divided as they leave the internal flue; one-half returns along each side flue to the front of the boiler, and the whole then passes downwards into the central flue, travelling under the bottom of the boiler until the gases again reach the back end, where they pass into the chimney. In a few cases the arrangement is reversed, the gases first passing along the bottom flue and returning along the side flues. This latter arrangement, whilst promoting a more rapid circulation of water, has the disadvantage of requiring two dampers, and it is not suitable for those cases in which heavy deposits form on the bottoms of the boilers.

Vertical.

Where floor space is limited and also for small installations, other forms of cylindrical boilers are used, most of them being of the vertical type. That most commonly used is the simple vertical boiler, with a plain vertical fire-box, and an internal smoke stack traversing the steam space. The fire-box is made slightly tapering in diameter, the space between it and the shell being filled with water. In all but the small sizes cross tubes are generally fitted. These are made about 9 in. in diameter of 3/8-in. plate flanged at each end to enable them to be riveted to the fire-box plates. They are usually fitted with a slight inclination to facilitate water circulation. and a hand-hole closed by a suitable door is provided in the outer shell opposite to each tube for cleaning purposes. A boiler of this kind is illustrated in fig. 4. This form is often used on board ship for auxiliary purposes. Where more heating surface is required than can be obtained in the cross-tube boiler other types of vertical boiler are employed. For instance, in the "Tyne" boiler (fig. 5) the furnace is hemispherical, and the products of combustion are led into an upper combustion chamber traversed by four or more inclined water-tubes of about 9 in. diameter and by several vertical water-tubes of less diameter. In the "Victoria" boiler made by Messrs Clarke, Chapman & Co., and illustrated in fig. 6, the furnace is hemispherical; the furnace gases are led to an internal combustion chamber, and thence through numerous horizontal smoke-tubes to a smoke-box placed on the side of the boiler. In the somewhat similar boiler known as the "Cochran," the combustion chamber is made with a "dry" back. Instead of a water space at the back of the chamber, doors lined with firebrick are fitted. These give easy access to the tube ends.

[Illustration: FIG. 3.--Lancashire Boiler.]

[Illustration: FIG. 4.--Simple Vertical Boiler (Messrs Tinker, Ltd.).]

Marine.

The cylindrical multitubular return tube boiler is in almost universal use in merchant steamers. It is made in various sizes ranging up to 17 ft. in diameter, the usual working pressure being from 160 to 200 lb per sq. in., although in some few cases pressures of 265 lb. per sq. in. are in use. These boilers are of two types, double- and single-ended. In single-ended boilers, which are those most generally used, the furnaces are fitted at one end only and vary in number from one in the smallest boiler to four in the largest. Three furnaces are the most usual practice. Each furnace generally has its own separate combustion chamber. In four furnace boilers, however, one chamber is sometimes made common to the two middle furnaces, and sometimes one chamber is fitted to each pair of side furnaces. In double-ended boilers furnaces are fitted at each end. In some cases each furnace has a separate combustion chamber, but more usually one chamber is made to serve for two furnaces, one at each end of the boiler. The two types of boilers are shown in figs. 7 and 8, which illustrate boilers made by Messrs D. Rowan & Co. of Glasgow, and which may be taken as representing good modern practice. The furnaces used in the smaller sizes are often of the plain cylindrical type, the thickness of plate varying from 3/8 in. up to 3/4 in. according to the diameter of the furnace and the working pressure. Occasionally furnaces with "Adamson" joints similar to those used in Lancashire boilers are employed, but for large furnaces and for high pressures corrugated or ribbed furnaces are usually adopted. Sketches of the sections of these are shown in fig. 9. The sections of the Morison, Fox and Deighton types are made from plates originally rolled of a uniform thickness, made into a cylindrical form with a welded longitudinal joint and then corrugated, the only difference between them being in the shapes of the corrugations. In the other three types the plates from which the furnaces are made are rolled with ribs or thickened portions at distances of 9 in. These furnaces are stronger to resist collapse than plain furnaces of the same thickness, and accommodate themselves more readily to changes of temperature.

[Illustration: FIG. 5.--Vertical Boiler with Water-tubes (the "Tyne," by Messrs Clarke, Chapman & Co.).]

There are two distinct types of connexion between the furnaces and the combustion chambers. In one, shown in fig. 8, the furnace is flanged at the crown portion for riveting to the tube plate, and the lower part of the furnace is riveted to the "wrapper" or side plate of the combustion chamber. In the other type, shown in fig. 7, and known generally as the "Gourlay back end," the end of the furnace is contracted into an oval conical form, and is then flanged outwards round the whole of its circumference. The tube plate is made to extend to the bottom of the combustion chamber, and the furnace is riveted to the tube plate. The advantage of the Gourlay back end is that in case of accident to the furnace it can be removed from the boiler and be replaced by one of the same design without disturbing the end plates, which is not possible with the other design. The Gourlay back end, however, is not so stiff as the other, and more longitudinal stays are required in the boiler.

[Illustration: FIG. 6.--Vertical Boiler with internal combustion chamber (the "Victoria," by Messrs Clarke, Chapman & Co.).]

[Illustration: FIG. 7.--Single-ended Marine Boiler.]

The flat sides and backs of the combustion chambers are stayed either to one another or to the shell of the boiler by numerous screw stays which are screwed through the two plates they connect, and which are nearly always fitted with nuts inside the combustion chambers. The tops of the chambers are usually stayed by strong girders resting upon the tube plates and chamber back plates. In a few cases, however, they are stayed by vertical stays attached to T bars riveted to the boiler shell. A few boilers are made in which the chamber tops are strengthened by heavy transverse girder plates. The end plates of the boiler in the steam space and below the combustion chambers are stayed by longitudinal stays passing through the whole length of the boiler and secured by double nuts at each end. The tube plates are strengthened by stay tubes screwed into them.

Where natural or chimney draught is used the tubes are generally made 3 or 3-1/4 in. outside diameter and are rarely more than 7 ft. long, but where "forced" draught is employed they are usually made 2-1/2 in. diameter and 8 to 8-1/2 ft. long. A clear space of 1-1/4 in. between the tubes is almost always arranged for, irrespective of size of tubes.

[Illustration: FIG. 8.--Double-ended Marine Boiler.]

Stay tubes are screwed at both ends, the threads of the two ends being continuous so that they can be screwed into both tube plates; occasionally nuts are fitted to the front ends. The stay tubes are expanded into the plates and then beaded over.

Locomotive.