Boric acid crystallizes from water in white nacreous laminae belonging to the triclinic system; it is difficultly soluble in cold water, but dissolves readily in hot water. It is one of the “weak” acids, its dissociation constant being only 0.08169 (J. Walker,Jour. of Chem. Soc., 1900, lxxvii. 5), and consequently its salts are appreciably hydrolysed in aqueous solution. The free acid turns blue litmus to a claret colour. Its action upon turmeric is characteristic; a turmeric paper moistened with a solution of boric acid turns brown, the colour becoming much darker as the paper dries; while the addition of sodium or potassium hydroxide turns it almost black. Boric acid is easily soluble in alcohol, and if the vapour of the solution be inflamed it burns with a characteristic vivid green colour. The acid on being heated to 100° C. loses water and is converted intometaboric acid, HBO3; at 140° C.,pyroboric acid, H2B4O7, is produced; at still higher temperatures, boron trioxide is formed. The salts of the normal or orthoboric acid in all probability do not exist; metaboric acid, however, forms several well-defined salts which are readily converted, even by carbon dioxide, into salts of pyroboric acid. That orthoboric acid is a tribasic acid is shown by the formation of ethyl orthoborate on esterification, the vapour density of which corresponds to the molecular formula B(OC2H5)3; the molecular formula of the acid must consequently be B(OH)3or H3BO3. The metallic borates are generally obtained in the hydrated condition, and with the exception of those of the alkali metals, are insoluble in water. The most important of the borates is sodium pyroborate or borax (q.v.).Borax and boracic acid are feeble but useful antiseptics. Hence they may be used to preserve food-substances, such as milk and butter (seeAdulteration). In medicine boracic acid is used in solution to relieve itching, but its chief use is as a mild antiseptic to impregnate lint or cotton-wool. Recent work has shown it is too feeble to be relied upon alone, but where really efficient antiseptics, such as mercuric chloride and iodide, and carbolic acid, have been already employed, boracic acid (which, unlike these, is non-poisonous and non-irritant) may legitimately be used to maintain the aseptic or non-bacterial condition which they have obtained. Borax taken internally is of some value in irritability of the bladder, but as a urinary antiseptic it is now surpassed by several recently introduced drugs, such as urotropine.
Boric acid crystallizes from water in white nacreous laminae belonging to the triclinic system; it is difficultly soluble in cold water, but dissolves readily in hot water. It is one of the “weak” acids, its dissociation constant being only 0.08169 (J. Walker,Jour. of Chem. Soc., 1900, lxxvii. 5), and consequently its salts are appreciably hydrolysed in aqueous solution. The free acid turns blue litmus to a claret colour. Its action upon turmeric is characteristic; a turmeric paper moistened with a solution of boric acid turns brown, the colour becoming much darker as the paper dries; while the addition of sodium or potassium hydroxide turns it almost black. Boric acid is easily soluble in alcohol, and if the vapour of the solution be inflamed it burns with a characteristic vivid green colour. The acid on being heated to 100° C. loses water and is converted intometaboric acid, HBO3; at 140° C.,pyroboric acid, H2B4O7, is produced; at still higher temperatures, boron trioxide is formed. The salts of the normal or orthoboric acid in all probability do not exist; metaboric acid, however, forms several well-defined salts which are readily converted, even by carbon dioxide, into salts of pyroboric acid. That orthoboric acid is a tribasic acid is shown by the formation of ethyl orthoborate on esterification, the vapour density of which corresponds to the molecular formula B(OC2H5)3; the molecular formula of the acid must consequently be B(OH)3or H3BO3. The metallic borates are generally obtained in the hydrated condition, and with the exception of those of the alkali metals, are insoluble in water. The most important of the borates is sodium pyroborate or borax (q.v.).
Borax and boracic acid are feeble but useful antiseptics. Hence they may be used to preserve food-substances, such as milk and butter (seeAdulteration). In medicine boracic acid is used in solution to relieve itching, but its chief use is as a mild antiseptic to impregnate lint or cotton-wool. Recent work has shown it is too feeble to be relied upon alone, but where really efficient antiseptics, such as mercuric chloride and iodide, and carbolic acid, have been already employed, boracic acid (which, unlike these, is non-poisonous and non-irritant) may legitimately be used to maintain the aseptic or non-bacterial condition which they have obtained. Borax taken internally is of some value in irritability of the bladder, but as a urinary antiseptic it is now surpassed by several recently introduced drugs, such as urotropine.
BORING.The operations of deep boring are resorted to for ascertaining the nature, thickness and extent of the variousgeological formations underlying the surface of the earth. Among the purposes for which boring is specifically employed are: (1) prospecting or searching for mineral deposits; (2) sinking petroleum, natural gas, artesian or salt wells; (3) determining the depth below the surface of bed-rock or other firm substratum, together with the character of the overlying materials, preparatory to mining or civil engineering operations; (4) carrying on geological or other scientific explorations.
Prospecting by boring is practised most successfully in the case of mineral deposits of large area, which are nearly horizontal, or at least not highly inclined;e.g.deposits of coal, iron, lead and salt. Wide, flat beds of such minerals may be pierced at any desired number of points. The depth at which each hole enters the deposit and the thickness of the mineral itself are readily ascertained, so that a map may be constructed with some degree of accuracy. Samples of the mineral are also secured, furnishing data as to the value of the deposit. While boring is sometimes adopted for prospecting irregular and steeply inclined mineral deposits of small area, the results are obviously less trustworthy than under the conditions named above, and may be actually misleading unless a large number of holes are bored. Incidentally, bore-holes supply information as to the character and depth of the valueless depositions of earth or rock overlying the mineral deposit. Such data assist in deciding upon the appropriate method for, and in estimating the cost of, sinking shafts or driving tunnels for the development and exploitation of the deposit. In sinking petroleum wells, boring serves not only for discovering the oil-bearing strata but also for extracting the oil. This industry has become of great importance in many parts of the United States, in southern Russia and elsewhere. Rock salt deposits are sometimes worked through bore-holes, by introducing water and pumping out the solution of brine for further treatment. The sinking of artesian wells is another application of boring. They are often hundreds, and sometimes thousands, of feet in depth. A well in St Louis, Missouri, has a depth of 3843 ft.
Boring is useful in mines themselves for a variety of purposes, such as exploring the deposit ahead of the workings, searching for neighbouring veins, and sounding the ground on approaching dangerous inundated workings. In the coal regions of Pennsylvania, bore-holes are often sunk for carrying steam pipes and hoisting ropes underground at points remote from a shaft.
Several of the methods of boring in soft ground are employed in connexion with civil engineering operations; as for ascertaining the depth below the surface to solid rock, preparatory to excavating for and designing deep foundations for heavy structures, and for estimating the cost of large scale excavations in earth and rock.
Lastly, a number of deep holes have been bored for geological exploration or for observing the increase of temperature in depth in the earth’s crust; for example, at Paruschowitz, Silesia, about 6700 ft. deep; at Leipzig, Germany, 6265 ft.; near Pittsburg, Pennsylvania, 5532 ft.; and at Wheeling, West Virginia, nearly 5000 ft. The two last mentioned were intended to obtain as complete a knowledge as possible of the bituminous coal and oil-bearing formations.
There are five methods of boring, viz.: by (1) earth augers, (2) drive pipes, (3) long, jointed rods and drop drill, (4) the rope system, in which the rods are replaced by rope, (5) rotary drills. The first two methods are adapted to soft or earthy soils only; the others are for rock.
1.Earth augerscomprise spiral and pod augers. The ordinary spiral auger resembles the wood auger commonly used by carpenters. It is attached to the rod or stem by a socket joint, successive sections of rod being added as the hole is deepened. The auger is rotated by means of horizontal levers, clamped to the rod—by hand for holes of small diameter (2 to 6 in.), the larger sizes (8 to 16 in.) by horse power. Clayey, cohesive soils, containing few stones, are readily bored; stony ground with difficulty. The operation of the auger is intermittent. After a few revolutions it is raised and emptied, the soil clinging between the spirals. Depths to 50 or 60 ft. are usually bored by hand; deeper holes by horse power. For sandy, non-cohesive soils, the auger may be encircled by a close-fitting sheet-iron cylinder to prevent the soil from falling out.Pod augers generally vary in diameter from 8 to 20 in. A common form (fig. l) consists of two curved iron plates, one attached to the rod rigidly, the other by hinge and key. By being turned through a few revolutions the pod is filled, and is then raised and emptied. For boring in sandy soils, the open sides are closed by hinged plates. Fig. 2 shows another type of pod auger. For holes of large diameter earth augers are handled with the aid of a light derrick.Fig.1.Fig.2.Pod Auger.2.Drive pipesare widely used, both for testing the depth and character of soft material overlying solid rock and as a necessary preliminary to rock boring, when some thickness of surface soil must first be passed through. In its simplest form the drive pipe consists of one or more lengths of wrought iron pipe, open at both ends and from ½ in. to 6 in. diameter. When of small size the pipe is driven by a heavy hammer; for deep and large holes, a light pile-driver becomes necessary. The lower end of the pipe is provided with an annular steel shoe; the upper end has a drivehead for receiving the blows of the hammer. Successive lengths are screwed on as required. For shallow holes the pipe is cleaned out by a “bailer” or “sand-pump”—a cylinder 4 to 6 ft. long, with a valve in the lower end. It is lowered at intervals, filled by being dashed up and down, and then raised and emptied. If, after reaching some depth, the external frictional resistance prevents the pipe from sinking farther, another pipe of small diameter may be inserted and the driving continued. Drive pipes are often sunk by applying weights at the surface and slowly rotating by a lever. Two pipes are then used, one inside the other. Water is pumped down the inner pipe, thus loosening the soil, raising the debris and increasing the speed of driving. The “driven well” for water supply is an adaptation of the drive pipe and put down in the same way.3.Drill and Rods.—This method has long been used in Europe and elsewhere for deep boring. In the United States it is rarely employed for depths greater than 200 or 300 ft. The usual form of cutting tool or drill is shown in fig. 3. The iron rods are from 1 to 2 in. square, in long lengths with screw joints (fig. 4). Wooden rods are occasionally used. For shallow holes (50 to 75 ft.) the work is done by hand, one or two cross-bars being clamped to the rod. The men alternately raise and drop the drill, meanwhile slowly walking around and around to rotate the bit and so keep the hole true. The cuttings are cleaned out by a bailer, as for drive pipes.Fig.3Drill Bit.Fig.4.Rod Joint.Fig.5.Sliding Link.In boring by hand, the practical limit of depth is soon reached, on account of the increasing weight of the rods. For going deeper a “spring-pole” may be used. This is a tapering pole, say 30 ft. long and 5 or 6 in. diameter at the small end. It rests in an inclined position on a fulcrum set about 10 ft. from the butt, the latter being firmly fixed. The rods are suspended from the end of the pole, which extends at a height of several feet over the mouth of the hole. With the aid of the spring of the pole the strokes are produced by a slight effort on the part of the driller. Average speeds of 6 to 10 ft. per 10 hours are easily made, to depths of 200 to 250 ft.For deep boring the rod system requires a more elaborate plant. The rods are suspended from a heavy “walking beam” or lever, usually oscillated by a steam engine. By means of a screw-feed device, the rods, which are rotated slightly after every stroke, are gradually fed down as the hole is deepened, length after length being added. A tall derrick carries the sheaves and ropes by which the rods and tools are manipulated. The drill bit cannot be attached rigidly to the rods as in shallow boring, because the momentum of the heavy moving parts, transmitted directly to the bit as the blow is struck, would cause excessive vibration and breakage. It becomes necessary, therefore, to introduce a sliding-link joint between the rods and bit. One form of link is shown in fig. 5. On striking its blow, the bit comes to rest, while the rods continue to descend to the end of the stroke, the upper member of the link sliding down upon the lower. Then, on the up stroke the lower link, with the bit, is raised for delivering another blow. For large holes the striking weight is, say, 800 to 1000 ℔, length of stroke 2½ to 5 ft., and speed from 20 to 30 strokes per minute.Fig.6.Kind Free-Falling Tool.By using the sliding link the cross-section and weight of the rods may be greatly reduced, the only strain being that of tension. To deliver a sharp, effective blow, however, the rods must drop with a quick stroke, which brings a heavy strain upon the operating machinery. For overcoming this difficulty, various “free-falling tools” have been devised. By these the bit is allowed to fall by gravity; the rod follows on its measured down stroke, and picks up the bit. Free-falling tools are of two classes: (1) those by which the bit is released automatically; (2) those operated by a sudden twist imparted to the rod by the drillman. One of the best known of the first class is the Kind free-fall (fig. 6). The shank of the bit is gripped and released by the jaws J, J, worked through a toggle joint by movements of the disk D. When the rod begins its downward stroke, the resistance of the water in the hole slightly raises D, thus opening the jaws and releasing the bit, which falls by gravity. On reaching the end of the stroke the jaws again catch the shank of the bit and raise it for delivering another blow. The Fabian free-fall may be noted as an example of the second class (see Köhler,Lehrbuch der Bergbaukunde, p. 57). Tools are sometimes used for cutting an annular groove in the bottom of the hole, and raising to the surface the core so formed, for observing the character of the rock.4.Rope and Drop Tools.—This method was long ago used in China. Because of its extensive application in the oil-fields it is generally designated in the United States as the “oil-well system.” In its various modifications it is often employed also in general prospecting of mineral deposits and in sinking artesian, natural gas and salt wells. One of its forms is known in England as the Mather & Platt system.Fig.7.Temper Screw.The chief point of difference from rod-boring is the substitution of rope for the jointed rods. For deep boring it possesses the advantage of saving the large amount of time consumed in raising and lowering the rods, as required whenever the hole is to be cleaned out, or a dull bit replaced, since the tools are rapidly run up or down by means of the rope with which they are operated while drilling. The speed of rope-boring is therefore but little affected by increase of depth, while with rod-boring it falls off rapidly. In its simplest form the so-called “string of tools,” suspended from the rope, is composed of the bit or drill, jars and rope-socket. The jars are a pair of sliding links, similar to those used for rod-boring, but serving a different purpose, viz. to produce a sharp shock on the upward stroke, as the jars come together, for loosening the bit should it tend to stick fast in the hole. A heavy bar (auger stem) is generally inserted between the jars and bit, for increasing the force of the blow. The weight of another bar above the jars (sinker-bar) keeps the rope taut. The length of stroke and feed are regulated by the “temper-screw” (fig. 7), a feed device resembling that used for rod-boring. Clamped to it is the drill rope, which is let out at intervals, as the hole is deepened. The bits usually range from 3 to 8 in. diameter, the speed of boring being generally between 20 and 40 ft. per 24 hours, according to the kind of rock. A great variety of special “fishing tools” are made, for use in case of breakage of parts in the hole or other accident.5.Diamond Drill.—The methods described above are capable of boring holes vertically downward only. By the diamond drill, holes can be bored in any direction, from vertically downward to vertically upward. It has the further advantage of making an annular hole from which is obtained a core, furnishing a practically complete cross-section of the strata penetrated; the thickness and character of each stratum are shown, together with its depth below the surface. Thus, the diamond drill is peculiarly well adapted for prospecting mineral deposits from which samples are desired. The first practical application of diamonds for drilling in rock was made in 1863 by Professor Rudolph Leschot, a civil engineer of Paris.The apparatus consists essentially of a line of hollow rods, coupled by screw joints, an annular steel bit or crown, set with diamonds, being attached to the lower end. By means of a small engine on the surface the rods are rapidly rotated and fed down automatically as the hole deepened. The speed of rotation is from 300 to 800 revolutions per minute, depending on the character of the rock and diameter of the bit. While boring a stream of water is forced down the hollow rods by a pump, passing back to the surface through the annular space between the rods and the walls of the drill hole. The cuttings are thus carried to the surface, leaving the bottom of the hole clean and unobstructed. For recovering the core and inspecting the bit and diamonds, the rods are raised at every 3 to 8 ft. of depth. This is done by a small drum and rope, operated by the driving engine.Fig.8.—LittleChampion Rock Drill.Fig.9.Fig.10.Diamond Drill Bit.Diamond drills of standard designs (fig. 8) bore holes from 19⁄16to 2¾ in. diameter, yielding cores of 1 to 115⁄16in. diameter, and are capable of reaching depths of a few hundred to 4000 ft. or more. They require from 8 to 30 boiler horse-power. Large machines will bore shallower holes up to 6, 9 or even 12 in. diameter. For operating in underground workings of mines, small and compact machines are sometimes mounted on columns (fig. 9). They bore 1¼ to 19⁄16in. holes to depths of 300 to 400 ft., cores being7⁄8to 1 in. diameter. Hand-power drills are also built. In the South African goldfields several diamond drill holes from 4500 to 5200 ft. deep have been successfully bored. Rates of advance for core-drilling to moderate depths range usually from 2 to 3 ft. per hour, including ordinary delays, though in favourable rock much higher speeds are often attained. In deep holes the speeds diminish, because of time consumed in raising and lowering the rods. If no core is desired a “solid bit” is used. The drilling then proceeds faster, as it is only necessary to raise the rods occasionally, for examining the condition of the bit.Fig.11.Core Lifter and BarrelThe driving engine has two inclined cylinders, coupled to a crank-shaft, by which, through gearing, the drill-rod is rotated. The rods are wrought iron or steel tubes, in 5 to 10 ft. lengths. For producing the feed two devices are employed, the differential screw and hydraulic cylinder. For thedifferential feed(fig. 9) the engine has a hollow left-hand threaded screw-shaft, to which the rods are coupled. This shaft is driven by a spline and bevel gearing and is supported by a threaded feed-nut, carried in the lower bearing. Geared to the screw-shaft is a light counter-shaft. By properly proportioning the number of teeth in the system of gear-wheels, the feed-nut is caused to revolve a little faster than the screw-shaft, so that the drill-rod is fed downward a small fraction of an inch for each revolution. To vary the rate of feed, as suitable for different rocks, three pairs of gears with different ratios of teeth are provided. The screw-shaft and gearing are carried by a swivel-head, which can be rotated in a vertical plane, for boring holes at an angle.Thehydraulic feedis an improvement on the above, in that the rate of feed is independent of the rotative speed of the rods and can be adjusted with the utmost nicety. There are either one or two feed cylinders, supplied with water from the pump. The rod, while rotating freely, is supported by the feed cylinder piston and caused to move slowly downward by allowing the water to pass from the lower to the upper part of the cylinder. A valve regulates the passage of the water and hence the rate of feed.The bit (fig. 10 and fig. 11, B) is of soft steel, set with six to eight or more diamonds according to its diameter. The diamonds, usually from 1½ to 2½ carats in size, are carefully set in the bit, projecting but slightly from its surface. Two kinds of diamonds are used, “carbons” and “borts.” The carbons are opaque, darkin colour, tougher than the brilliant, and have no cleavage planes. They are therefore suitable for drilling in hard rock. Borts are rough, imperfect brilliants, and are best used for the softer rocks. As the bit wears, the stones must be reset from time to time. The wear of carbons in a well-set bit is small, though extremely variable. Above the bit are the core-lifter and core-barrel. The core-lifter (fig. 11, A) is a device for gripping and breaking off the core and raising it to the surface. The barrel, 3 to 10 ft. long, fits closely in the hole and is often spirally grooved for the passage of the water and debris. It serves partly as a guide, tending to keep the hole straight, partly for holding and protecting the core.Diamond drills do not work satisfactorily in broken, fissured rock, as the carbons are liable to be injured, loosened or torn from their settings. In these circumstances, and for soft rocks, the diamond bit may be replaced by a steel toothed bit. Another apparatus for core-drilling is the Davis Calyx drill. For hard rock it has an annular bit, accompanied by a quantity of chilled steel shot; for soft rock, a toothed bit is used.Diamond drill holes are rarely straight, and usually deviate considerably from the direction in which they are started. Very deep holes have been found to vary as much as 45° and even 60° from their true direction. This is due to the fact that the rods do not fit closely in the hole and therefore bend. It is also likely to occur in drilling through inclined strata, specially when of different degrees of hardness. By using a long and closely fitting core-barrel the liability to deviation is reduced, but cannot be wholly prevented. Holes which are nearly horizontal always deflect upward, because the sag of the rods tilts up the bit. Diamond drill holes should therefore always be surveyed. This is done by lowering into the hole instruments for observing at a number of successive points the direction and degree of deviation.1If accurately surveyed a crooked hole may be quite as useful as a straight one.Authorities.—For further information on boring seeTrans. Amer. Inst. Mining Engs.vol. ii. p. 241, vol. xxvii. p. 123; C. le Neve Foster,Text-book of Ore and Stone Mining, chap. iii.;Glückauf, 9th December 1899, 20th and 27th May 1905;Scientific American, 21st August 1886;Engineering and Mining Jour.vol. lviii. p. 268, vol. lxx. p. 699, vol. lxxx. p. 920;Trans. Inst. Mining Engs., England, vol. xxiii. p. 685;School of Mines Quarterly, N. Y., vol. xvi. p. 1;Zeitschr. für Berg- Hütten- und Salinenwesen, vol. xxv. p. 29; Denny, “Diamond Drilling,”Mines and Minerals, vol. xx., August 1899, p. 7, to January 1900, p. 241;Mining Jour., 26th January 1901;Mining and Scientific Press, 28th November 1903, p. 353;Öst. Zeitschr. für Berg- und Hüttenwesen, 21st May, 4th June 1904;Trans. Inst. Mining and Metallurgy, vol. xii. p. 301;Engineering Magazine, March 1896, p. 1075.
1.Earth augerscomprise spiral and pod augers. The ordinary spiral auger resembles the wood auger commonly used by carpenters. It is attached to the rod or stem by a socket joint, successive sections of rod being added as the hole is deepened. The auger is rotated by means of horizontal levers, clamped to the rod—by hand for holes of small diameter (2 to 6 in.), the larger sizes (8 to 16 in.) by horse power. Clayey, cohesive soils, containing few stones, are readily bored; stony ground with difficulty. The operation of the auger is intermittent. After a few revolutions it is raised and emptied, the soil clinging between the spirals. Depths to 50 or 60 ft. are usually bored by hand; deeper holes by horse power. For sandy, non-cohesive soils, the auger may be encircled by a close-fitting sheet-iron cylinder to prevent the soil from falling out.
Pod augers generally vary in diameter from 8 to 20 in. A common form (fig. l) consists of two curved iron plates, one attached to the rod rigidly, the other by hinge and key. By being turned through a few revolutions the pod is filled, and is then raised and emptied. For boring in sandy soils, the open sides are closed by hinged plates. Fig. 2 shows another type of pod auger. For holes of large diameter earth augers are handled with the aid of a light derrick.
2.Drive pipesare widely used, both for testing the depth and character of soft material overlying solid rock and as a necessary preliminary to rock boring, when some thickness of surface soil must first be passed through. In its simplest form the drive pipe consists of one or more lengths of wrought iron pipe, open at both ends and from ½ in. to 6 in. diameter. When of small size the pipe is driven by a heavy hammer; for deep and large holes, a light pile-driver becomes necessary. The lower end of the pipe is provided with an annular steel shoe; the upper end has a drivehead for receiving the blows of the hammer. Successive lengths are screwed on as required. For shallow holes the pipe is cleaned out by a “bailer” or “sand-pump”—a cylinder 4 to 6 ft. long, with a valve in the lower end. It is lowered at intervals, filled by being dashed up and down, and then raised and emptied. If, after reaching some depth, the external frictional resistance prevents the pipe from sinking farther, another pipe of small diameter may be inserted and the driving continued. Drive pipes are often sunk by applying weights at the surface and slowly rotating by a lever. Two pipes are then used, one inside the other. Water is pumped down the inner pipe, thus loosening the soil, raising the debris and increasing the speed of driving. The “driven well” for water supply is an adaptation of the drive pipe and put down in the same way.
3.Drill and Rods.—This method has long been used in Europe and elsewhere for deep boring. In the United States it is rarely employed for depths greater than 200 or 300 ft. The usual form of cutting tool or drill is shown in fig. 3. The iron rods are from 1 to 2 in. square, in long lengths with screw joints (fig. 4). Wooden rods are occasionally used. For shallow holes (50 to 75 ft.) the work is done by hand, one or two cross-bars being clamped to the rod. The men alternately raise and drop the drill, meanwhile slowly walking around and around to rotate the bit and so keep the hole true. The cuttings are cleaned out by a bailer, as for drive pipes.
In boring by hand, the practical limit of depth is soon reached, on account of the increasing weight of the rods. For going deeper a “spring-pole” may be used. This is a tapering pole, say 30 ft. long and 5 or 6 in. diameter at the small end. It rests in an inclined position on a fulcrum set about 10 ft. from the butt, the latter being firmly fixed. The rods are suspended from the end of the pole, which extends at a height of several feet over the mouth of the hole. With the aid of the spring of the pole the strokes are produced by a slight effort on the part of the driller. Average speeds of 6 to 10 ft. per 10 hours are easily made, to depths of 200 to 250 ft.
For deep boring the rod system requires a more elaborate plant. The rods are suspended from a heavy “walking beam” or lever, usually oscillated by a steam engine. By means of a screw-feed device, the rods, which are rotated slightly after every stroke, are gradually fed down as the hole is deepened, length after length being added. A tall derrick carries the sheaves and ropes by which the rods and tools are manipulated. The drill bit cannot be attached rigidly to the rods as in shallow boring, because the momentum of the heavy moving parts, transmitted directly to the bit as the blow is struck, would cause excessive vibration and breakage. It becomes necessary, therefore, to introduce a sliding-link joint between the rods and bit. One form of link is shown in fig. 5. On striking its blow, the bit comes to rest, while the rods continue to descend to the end of the stroke, the upper member of the link sliding down upon the lower. Then, on the up stroke the lower link, with the bit, is raised for delivering another blow. For large holes the striking weight is, say, 800 to 1000 ℔, length of stroke 2½ to 5 ft., and speed from 20 to 30 strokes per minute.
By using the sliding link the cross-section and weight of the rods may be greatly reduced, the only strain being that of tension. To deliver a sharp, effective blow, however, the rods must drop with a quick stroke, which brings a heavy strain upon the operating machinery. For overcoming this difficulty, various “free-falling tools” have been devised. By these the bit is allowed to fall by gravity; the rod follows on its measured down stroke, and picks up the bit. Free-falling tools are of two classes: (1) those by which the bit is released automatically; (2) those operated by a sudden twist imparted to the rod by the drillman. One of the best known of the first class is the Kind free-fall (fig. 6). The shank of the bit is gripped and released by the jaws J, J, worked through a toggle joint by movements of the disk D. When the rod begins its downward stroke, the resistance of the water in the hole slightly raises D, thus opening the jaws and releasing the bit, which falls by gravity. On reaching the end of the stroke the jaws again catch the shank of the bit and raise it for delivering another blow. The Fabian free-fall may be noted as an example of the second class (see Köhler,Lehrbuch der Bergbaukunde, p. 57). Tools are sometimes used for cutting an annular groove in the bottom of the hole, and raising to the surface the core so formed, for observing the character of the rock.
4.Rope and Drop Tools.—This method was long ago used in China. Because of its extensive application in the oil-fields it is generally designated in the United States as the “oil-well system.” In its various modifications it is often employed also in general prospecting of mineral deposits and in sinking artesian, natural gas and salt wells. One of its forms is known in England as the Mather & Platt system.
The chief point of difference from rod-boring is the substitution of rope for the jointed rods. For deep boring it possesses the advantage of saving the large amount of time consumed in raising and lowering the rods, as required whenever the hole is to be cleaned out, or a dull bit replaced, since the tools are rapidly run up or down by means of the rope with which they are operated while drilling. The speed of rope-boring is therefore but little affected by increase of depth, while with rod-boring it falls off rapidly. In its simplest form the so-called “string of tools,” suspended from the rope, is composed of the bit or drill, jars and rope-socket. The jars are a pair of sliding links, similar to those used for rod-boring, but serving a different purpose, viz. to produce a sharp shock on the upward stroke, as the jars come together, for loosening the bit should it tend to stick fast in the hole. A heavy bar (auger stem) is generally inserted between the jars and bit, for increasing the force of the blow. The weight of another bar above the jars (sinker-bar) keeps the rope taut. The length of stroke and feed are regulated by the “temper-screw” (fig. 7), a feed device resembling that used for rod-boring. Clamped to it is the drill rope, which is let out at intervals, as the hole is deepened. The bits usually range from 3 to 8 in. diameter, the speed of boring being generally between 20 and 40 ft. per 24 hours, according to the kind of rock. A great variety of special “fishing tools” are made, for use in case of breakage of parts in the hole or other accident.
5.Diamond Drill.—The methods described above are capable of boring holes vertically downward only. By the diamond drill, holes can be bored in any direction, from vertically downward to vertically upward. It has the further advantage of making an annular hole from which is obtained a core, furnishing a practically complete cross-section of the strata penetrated; the thickness and character of each stratum are shown, together with its depth below the surface. Thus, the diamond drill is peculiarly well adapted for prospecting mineral deposits from which samples are desired. The first practical application of diamonds for drilling in rock was made in 1863 by Professor Rudolph Leschot, a civil engineer of Paris.
The apparatus consists essentially of a line of hollow rods, coupled by screw joints, an annular steel bit or crown, set with diamonds, being attached to the lower end. By means of a small engine on the surface the rods are rapidly rotated and fed down automatically as the hole deepened. The speed of rotation is from 300 to 800 revolutions per minute, depending on the character of the rock and diameter of the bit. While boring a stream of water is forced down the hollow rods by a pump, passing back to the surface through the annular space between the rods and the walls of the drill hole. The cuttings are thus carried to the surface, leaving the bottom of the hole clean and unobstructed. For recovering the core and inspecting the bit and diamonds, the rods are raised at every 3 to 8 ft. of depth. This is done by a small drum and rope, operated by the driving engine.
Diamond drills of standard designs (fig. 8) bore holes from 19⁄16to 2¾ in. diameter, yielding cores of 1 to 115⁄16in. diameter, and are capable of reaching depths of a few hundred to 4000 ft. or more. They require from 8 to 30 boiler horse-power. Large machines will bore shallower holes up to 6, 9 or even 12 in. diameter. For operating in underground workings of mines, small and compact machines are sometimes mounted on columns (fig. 9). They bore 1¼ to 19⁄16in. holes to depths of 300 to 400 ft., cores being7⁄8to 1 in. diameter. Hand-power drills are also built. In the South African goldfields several diamond drill holes from 4500 to 5200 ft. deep have been successfully bored. Rates of advance for core-drilling to moderate depths range usually from 2 to 3 ft. per hour, including ordinary delays, though in favourable rock much higher speeds are often attained. In deep holes the speeds diminish, because of time consumed in raising and lowering the rods. If no core is desired a “solid bit” is used. The drilling then proceeds faster, as it is only necessary to raise the rods occasionally, for examining the condition of the bit.
The driving engine has two inclined cylinders, coupled to a crank-shaft, by which, through gearing, the drill-rod is rotated. The rods are wrought iron or steel tubes, in 5 to 10 ft. lengths. For producing the feed two devices are employed, the differential screw and hydraulic cylinder. For thedifferential feed(fig. 9) the engine has a hollow left-hand threaded screw-shaft, to which the rods are coupled. This shaft is driven by a spline and bevel gearing and is supported by a threaded feed-nut, carried in the lower bearing. Geared to the screw-shaft is a light counter-shaft. By properly proportioning the number of teeth in the system of gear-wheels, the feed-nut is caused to revolve a little faster than the screw-shaft, so that the drill-rod is fed downward a small fraction of an inch for each revolution. To vary the rate of feed, as suitable for different rocks, three pairs of gears with different ratios of teeth are provided. The screw-shaft and gearing are carried by a swivel-head, which can be rotated in a vertical plane, for boring holes at an angle.
Thehydraulic feedis an improvement on the above, in that the rate of feed is independent of the rotative speed of the rods and can be adjusted with the utmost nicety. There are either one or two feed cylinders, supplied with water from the pump. The rod, while rotating freely, is supported by the feed cylinder piston and caused to move slowly downward by allowing the water to pass from the lower to the upper part of the cylinder. A valve regulates the passage of the water and hence the rate of feed.
The bit (fig. 10 and fig. 11, B) is of soft steel, set with six to eight or more diamonds according to its diameter. The diamonds, usually from 1½ to 2½ carats in size, are carefully set in the bit, projecting but slightly from its surface. Two kinds of diamonds are used, “carbons” and “borts.” The carbons are opaque, darkin colour, tougher than the brilliant, and have no cleavage planes. They are therefore suitable for drilling in hard rock. Borts are rough, imperfect brilliants, and are best used for the softer rocks. As the bit wears, the stones must be reset from time to time. The wear of carbons in a well-set bit is small, though extremely variable. Above the bit are the core-lifter and core-barrel. The core-lifter (fig. 11, A) is a device for gripping and breaking off the core and raising it to the surface. The barrel, 3 to 10 ft. long, fits closely in the hole and is often spirally grooved for the passage of the water and debris. It serves partly as a guide, tending to keep the hole straight, partly for holding and protecting the core.
Diamond drills do not work satisfactorily in broken, fissured rock, as the carbons are liable to be injured, loosened or torn from their settings. In these circumstances, and for soft rocks, the diamond bit may be replaced by a steel toothed bit. Another apparatus for core-drilling is the Davis Calyx drill. For hard rock it has an annular bit, accompanied by a quantity of chilled steel shot; for soft rock, a toothed bit is used.
Diamond drill holes are rarely straight, and usually deviate considerably from the direction in which they are started. Very deep holes have been found to vary as much as 45° and even 60° from their true direction. This is due to the fact that the rods do not fit closely in the hole and therefore bend. It is also likely to occur in drilling through inclined strata, specially when of different degrees of hardness. By using a long and closely fitting core-barrel the liability to deviation is reduced, but cannot be wholly prevented. Holes which are nearly horizontal always deflect upward, because the sag of the rods tilts up the bit. Diamond drill holes should therefore always be surveyed. This is done by lowering into the hole instruments for observing at a number of successive points the direction and degree of deviation.1If accurately surveyed a crooked hole may be quite as useful as a straight one.
Authorities.—For further information on boring seeTrans. Amer. Inst. Mining Engs.vol. ii. p. 241, vol. xxvii. p. 123; C. le Neve Foster,Text-book of Ore and Stone Mining, chap. iii.;Glückauf, 9th December 1899, 20th and 27th May 1905;Scientific American, 21st August 1886;Engineering and Mining Jour.vol. lviii. p. 268, vol. lxx. p. 699, vol. lxxx. p. 920;Trans. Inst. Mining Engs., England, vol. xxiii. p. 685;School of Mines Quarterly, N. Y., vol. xvi. p. 1;Zeitschr. für Berg- Hütten- und Salinenwesen, vol. xxv. p. 29; Denny, “Diamond Drilling,”Mines and Minerals, vol. xx., August 1899, p. 7, to January 1900, p. 241;Mining Jour., 26th January 1901;Mining and Scientific Press, 28th November 1903, p. 353;Öst. Zeitschr. für Berg- und Hüttenwesen, 21st May, 4th June 1904;Trans. Inst. Mining and Metallurgy, vol. xii. p. 301;Engineering Magazine, March 1896, p. 1075.
(R. P.*)
1Brough,Mine Surveying, pp. 276-278; Marriott,Trans. Inst. Mining and Metallurgy, vol. xiv. p. 255.
1Brough,Mine Surveying, pp. 276-278; Marriott,Trans. Inst. Mining and Metallurgy, vol. xiv. p. 255.
BORIS FEDOROVICH GODUNOV,tsar of Muscovy (c.1551-1605), the most famous member of an ancient, now extinct, Russian family of Tatar origin, which migrated from the Horde to Muscovy in the 14th century. Boris’ career of service began at the court of Ivan the Terrible. He is mentioned in 1570 as taking part in the Serpeisk campaign as one of the archers of the guard. In 1571 he strengthened his position at court by his marriage with Maria, the daughter of Ivan’s abominable favourite Malyuta Skuratov. In 1580 the tsar chose Irene, the sister of Boris, to be the bride of the tsarevich Theodore, on which occasion Boris was promoted to the rank ofboyar. On his deathbed Ivan appointed Boris one of the guardians of his son and successor; for Theodore, despite his seven-and-twenty years, was of somewhat weak intellect. The reign of Theodore began with a rebellion in favour of the infant tsarevich Demetrius, the son of Ivan’s fifth wife Marie Nagaya, a rebellion resulting in the banishment of Demetrius, with his mother and her relations, to their appanage at Uglich. On the occasion of the tsar’s coronation (May 31, 1584), Boris was loaded with honours and riches, yet he held but the second place in the regency during the lifetime of his co-guardian Nikita Romanovich, on whose death, in August, he was left without any serious rival. A conspiracy against him of all the other great boyars and the metropolitan Dionysy, which sought to break Boris’ power by divorcing the tsar from Godunov’s childless sister, only ended in the banishment or tonsuring of the malcontents. Henceforth Godunov was omnipotent. The direction of affairs passed entirely into his hands, and he corresponded with foreign princes as their equal. His policy was generally pacific, but always most prudent. In 1595 he recovered from Sweden the towns lost during the former reign. Five years previously he had defeated a Tatar raid upon Moscow, for which service he received the title ofsluga, an obsolete dignity even higher than that of boyar. Towards Turkey he maintained an independent attitude, supporting an anti-Turkish faction in the Crimea, and furnishing the emperor with subsidies in his war against the sultan. Godunov encouraged English merchants to trade with Russia by exempting them from tolls. He civilized the north-eastern and south-eastern borders of Muscovy by building numerous towns and fortresses to keep the Tatar and Finnic tribes in order. Samara, Saratov, and Tsaritsyn and a whole series of lesser towns derive from him. He also re-colonized Siberia, which had been slipping from the grasp of Muscovy, and formed scores of new settlements, including Tobolsk and other large centres. It was during his government that the Muscovite church received its patriarchate, which placed it on an equality with the other Eastern churches and emancipated it from the influence of the metropolitan of Kiev. Boris’ most important domestic reform was theukaz(1587) forbidding the peasantry to transfer themselves from one landowner to another, thus binding them to the soil. The object of this ordinance was to secure revenue, but it led to the institution of serfdom in its most grinding form. The sudden death of the tsarevich Demetrius at Uglich (May 15, 1591) has commonly been attributed to Boris, because it cleared his way to the throne; but this is no clear proof that he was personally concerned in that tragedy. The same may be said of the many, often absurd, accusations subsequently brought against him by jealous rivals or ignorant contemporaries who hated Godunov’s reforms as novelties.
On the death of the childless tsar Theodore (January 7, 1598), self-preservation quite as much as ambition constrained Boris to seize the throne. Had he not done so, lifelong seclusion in a monastery would have been his lightest fate. His election was proposed by the patriarch Job, who acted on the conviction that Boris was the one man capable of coping with the extraordinary difficulties of an unexampled situation. Boris, however, would only accept the throne from aZemsky Sobor, or national assembly, which met on the 17th of February, and unanimously elected him on the 21st. On the 1st of September he was solemnly crowned tsar. During the first years of his reign he was both popular and prosperous, and ruled the people excellently well. Enlightened as he was, he fully recognized the intellectual inferiority of Russia as compared with the West, and did his utmost to bring about a better state of things. He was the first tsar to import foreign teachers on a great scale, the first to send young Russians abroad to be educated, the first to allow Lutheran churches to be built in Russia. He also felt the necessity of a Baltic seaboard, and attempted to obtain Livonia by diplomatic means. He cultivated friendly relations with the Scandinavians, in order to intermarry if possible with foreign royal houses, so as to increase the dignity of his own dynasty. That Boris was one of the greatest of the Muscovite tsars there can be no doubt. But his great qualities were overbalanced by an incurable suspiciousness, which made it impossible for him to act cordially with those about him. His fear of possible pretenders induced him to go so far as to forbid the greatest of the boyars to marry. He also encouraged informers and persecuted suspects on their unsupported statements. The Romanov family in especial suffered severely from these delations. Boris died suddenly (April 13, 1605), leaving one son, Theodore II., who succeeded him for a few months and then was foully murdered by the enemies of the Godunovs.
See Platon Vasilievich Pavlov,On the Historical Significance of the Reign of Boris Godunov(Rus.) (Moscow, 1850); Sergyei Mikhailivich Solovev,History of Russia(Rus.) (2nd ed., vols. vii.-viii., St Petersburg, 1897).
See Platon Vasilievich Pavlov,On the Historical Significance of the Reign of Boris Godunov(Rus.) (Moscow, 1850); Sergyei Mikhailivich Solovev,History of Russia(Rus.) (2nd ed., vols. vii.-viii., St Petersburg, 1897).
(R. N. B.)
BORISOGLYEBSK,a town of Russia, in the government of Tambov, 100 m. S.S.E. of the city of that name, in 51° 22′ N. lat. and 43° 4′ E. long. It was founded in 1646 to defend the southern frontiers of Muscovy against the Crimean Tatars, and in 1696 was surrounded by wooden fortifications. The principal industries are the preparation of wool, iron-casting, soap-boiling, tallow-melting, and brick-making; and there is an active trade in grain, wool, cattle, and leather, and two important annual fairs. Pop. (1867) 12,254; (1897) 22,370.
BORKU,orBorgu, a region of Central Africa between 17° and 19° N. and 18° and 21° E., forming part of the transitional zone between the arid wastes of the Sahara and the fertile lands of the central Sudan. It is bounded N. by the Tibesti Mountains, and is in great measure occupied by lesser elevations belonging to the same system. These hills to the south and east merge into the plains of Wadai and Darfur. South-west, in the direction of Lake Chad, is the Bodele basin. The drainage of the country is to the lake, but the numerous khors with which its surface is scored are mostly dry or contain water for brief periods only. A considerable part of the soil is light sand drifted about by the wind. The irrigated and fertile portions consist mainly of a number of valleys separated from each other by low and irregular limestone rocks. They furnish excellent dates. Barley is also cultivated. The northern valleys are inhabited by a settled population of Tibbu stock, known as the Daza, and by colonies of negroes; the others are mainly visited by nomadic Berber and Arab tribes. The inhabitants own large numbers of goats and asses.
A caravan route from Barca and the Kufra oasis passes through Borku to Lake Chad. The country long remained unknown to Europeans. Gustav Nachtigal spent some time in it in the year 1871, and gave a valuable account of the region and its inhabitants in his book,Sahara und Sudan(Berlin, 1879-1889). In 1899 Borku, by agreement with Great Britain, was assigned to the French sphere of influence. The country, which had formerly been periodically raided by the Walad Sliman Arabs, was then governed by the Senussi (q.v.), who had placed garrisons in the chief centres of population. From it raids were made on French territory. In 1907 a French column from Kanem entered Borku, but after capturing Ain Galakka, the principal Senussi station, retired. Borku is also called Borgu, but must not be confounded with the Borgu (q.v.) west of the Niger.
A summary of Nachtigal’s writing on Borku will be found in section 28 ofGustav Nachtigal’s Reisen in der Sahara und im Sudan(1 vol.), arranged by Albert Fränkel (Leipzig, 1887). See also an article (with map) by Commdt. Bordeaux inLa Géographie, Oct. 1908.
A summary of Nachtigal’s writing on Borku will be found in section 28 ofGustav Nachtigal’s Reisen in der Sahara und im Sudan(1 vol.), arranged by Albert Fränkel (Leipzig, 1887). See also an article (with map) by Commdt. Bordeaux inLa Géographie, Oct. 1908.
BORKUM,an island of Germany, in the North Sea, belonging to the Prussian province of Hanover, the westernmost of the East Frisian chain, lying between the east and west arms of the estuary of the Ems, and opposite to the Dollart. Pop. about 2500. The island is 5 m. long and 2½ m. broad, is a favourite summer resort, and is visited annually by about 20,000 persons. There is a daily steamboat service with Emden, Leer and Hamburg during the summer months. The island affords pasture for cattle, and a breeding-place for sea-birds.
BORLASE, WILLIAM(1695-1772), English antiquary and naturalist, was born at Pendeen in Cornwall, of an ancient family, on the 2nd of February 1695. He was educated at Exeter College, Oxford, and in 1719 was ordained. In 1722 he was presented to the rectory of Ludgvan, and in 1732 he obtained in addition the vicarage of St Just, his native parish. In the parish of Ludgvan were rich copper works, abounding with mineral and metallic fossils, of which he made a collection, and thus was led to study somewhat minutely the natural history of the county. In 1750 he was admitted a fellow of the Royal Society; and in 1754 he published, at Oxford, hisAntiquities of Cornwall(2nd ed., London, 1769). His next publication wasObservations on the Ancient and Present State of the Islands of Scilly, and their Importance to the Trade of Great Britain(Oxford, 1756). In 1758 appeared hisNatural History of Cornwall. He presented to the Ashmolean museum, Oxford, a variety of fossils and antiquities, which he had described in his works, and received the thanks of the university and the degree of LL.D. He died on the 31st of August 1772. Borlase was well acquainted with most of the leading literary men of the time, particularly with Alexander Pope, with whom he kept up a long correspondence, and for whose grotto at Twickenham he furnished the greater part of the fossils and minerals.
Borlase’s letters to Pope, St Aubyn and others, with answers, fill several volumes of MS. There are also MS. notes on Cornwall, and a complete unpublished treatiseConcerning the Creation and Deluge. Some account of these MSS., with extracts from them, was given in theQuarterly Review, October 1875. Borlase’s memoirs of his own life were published in Nichol’sLiterary Anecdotes, vol. v.
Borlase’s letters to Pope, St Aubyn and others, with answers, fill several volumes of MS. There are also MS. notes on Cornwall, and a complete unpublished treatiseConcerning the Creation and Deluge. Some account of these MSS., with extracts from them, was given in theQuarterly Review, October 1875. Borlase’s memoirs of his own life were published in Nichol’sLiterary Anecdotes, vol. v.
BORMIO(Ger.Worms), a town of Lombardy, Italy, in the province of Sondrio, 41½ m. N.E. of the town of Sondrio. Pop. (1901) 1814. It is situated in the Valtellina (the valley of the Adda), 4020 ft. above sea-level, at the foot of the Stelvio pass, and, owing to its position, was of some military importance in the middle ages. It contains interesting churches and picturesque towers. A cemetery of pre-Roman date was discovered at Bormio in 1820.
The baths of Bormio, 2 m. farther up the valley, are mentioned by Pliny and Cassiodorus, the secretary of Theodoric, and are much frequented.
BORN, IGNAZ,Edler von(1742-1791), Austrian mineralogist and metallurgist, was born of a noble family at Karlsburg, in Transylvania, on the 26th of December 1742. Educated in a Jesuit college in Vienna, he was for sixteen months a member of the order, but left it and studied law at Prague. Then he travelled extensively in Germany, Holland and France, studying mineralogy, and on his return to Prague in 1770 entered the department of mines and the mint. In 1776 he was appointed by Maria Theresa to arrange the imperial museum at Vienna, where he was nominated to the council of mines and the mint, and continued to reside until his death on the 24th of July 1791. He introduced a method of extracting metals by amalgamation (Über das Anquicken der Erze, 1786), and other improvements in mining and other technical processes. His publications also includeLithophylacium Bornianum(1772-1775) andBergbaukunde(1789), besides several museum catalogues. Von Born attempted satire with no great success.Die Staatsperücke, a tale published without his knowledge in 1772, and an attack on Father Hell, the Jesuit, and king’s astronomer at Vienna, are two of his satirical works. Part of a satire, entitledMonachologia, in which the monks are described in the technical language of natural history, is also ascribed to him. Von Born was well acquainted with Latin and the principal modern languages of Europe, and with many branches of science not immediately connected with metallurgy and mineralogy. He took an active part in the political changes in Hungary. After the death of the emperor Joseph II., the diet of the states of Hungary rescinded many innovations of that ruler, and conferred the rights of denizen on several persons who had been favourable to the cause of the Hungarians, and, amongst others, on von Born. At the time of his death in 1791, he was employed in writing a work entitledFasti Leopoldini, probably relating to the prudent conduct of Leopold II., the successor of Joseph, towards the Hungarians.
BORNA,a town of Germany in the kingdom of Saxony, on the Wyhra at its junction with the Pleisse, 17 m. S. by E. of Leipzig by rail. Pop. (1905) 9176. The industries include peat-cutting, iron foundries, organ, pianoforte, felt and shoe factories.
BÖRNE, KARL LUDWIG(1786-1837), German political writer and satirist, was born on the 6th of May 1786 at Frankfort-On-Main, where his father, Jakob Baruch, carried on the business of a banker. He received his early education at Giessen, but as Jews were ineligible at that time for public appointments in Frankfort, young Baruch was sent to study medicine at Berlin under a physician, Markus Herz, in whose house he resided. Young Baruch became deeply enamoured of his patron’s wife, the talented and beautiful Henriette Herz (1764-1847), and gave vent to his adoration in a series of remarkable letters. Tiring of medical science, which he had subsequently pursued at Halle, he studied constitutional law and political science at Heidelberg and Giessen, and in 1811 took his doctor’s degree at the latter university. On his return to Frankfort, now constituted as a grand duchy under the sovereignty of the prince bishop Karl von Dalberg, he received (1811) the appointment of police actuary in that city. The old conditions, however, returned in 1814 and he was obliged to resign his office. Embittered by the oppression under which the Jews suffered in Germany, he engaged in journalism, and edited the Frankfort liberal newspapers,StaatsristrettoandDie Zeitschwingen. In 1818 he became a convert to Lutheranprotestantism, changing his name from Löb Baruch to Ludwig Börne. This step was taken less out of religious conviction than, as in the case of so many of his descent, in order to improve his social standing. From 1818 to 1821 he editedDie Wage, a paper distinguished by its lively political articles and its powerful but sarcastic theatrical criticisms. This paper was suppressed by the police authorities, and in 1821 Börne quitted for a while the field of publicist writing and led a retired life in Paris, Hamburg and Frankfort. After the July Revolution (1830), he hurried to Paris, expecting to find the newly-constituted state of society somewhat in accordance with his own ideas of freedom. Although to some extent disappointed in his hopes, he was not disposed to look any more kindly on the political condition of Germany; this lent additional zest to the brilliant satirical letters (Briefe aus Paris, 1830-1833, published Paris, 1834), which he began to publish in his last literary venture,La Balance, a revival under its French name ofDie Wage. TheBriefe aus Pariswas Börne’s most important publication, and a landmark in the history of German journalism. Its appearance led him to be regarded as one of the leaders of the new literary party of “Young Germany.” He died at Paris on the 12th of February 1837.
Börne’s works are remarkable for brilliancy of style and for a thorough French vein of satire. His best criticism is to be found in hisDenkrede auf Jean Paul(1826), a writer for whom he had warm sympathy and admiration, in hisDramaturgische Blätter(1829-1834), and the witty satire,Menzel der Franzosenfresser(1837). He also wrote a number of short stories and sketches, of which the best known are theMonographie der deutschen Postschnecke(1829) andDer Esskünstler(1822).
The first edition of hisGesammelte Schriftenappeared at Hamburg (1829-1834) in 14 volumes, followed by 6 volumes ofNachgelassene Schriften(Mannheim, 1844-1850); more complete is the edition in 12 volumes (Hamburg, 1862-1863), reprinted in 1868 and subsequently. The latest complete edition is that edited by A. Klaar (8 vols., Leipzig, 1900). For further biographical matter see K. Gutzkow,Börnes Leben(Hamburg, 1840), and M. Holzmann,L. Börne, sein Leben und sein Wirken(Berlin, 1888).Börnes Briefe an Henriette Herz(1802-1807), first published in 1861, have been re-edited by L. Geiger (Oldenburg, 1905), who has also published Börne’sBerliner Briefe(1828) (Berlin, 1905). See also Heine’s witty attack on Börne (Werke, ed. Elster, vii.), G. Gervinus’ essay in hisHistoriche Schriften(Darmstadt, 1838), and the chapters in G. Brandes,Hovedströmninger i det 19 de Aarhundredes Litteraturvol. vi. (Copenhagen, 1890, German trans. 1891; English trans. 1905), and in J. Proelss,Das junge Deutschland(Stuttgart, 1892).
The first edition of hisGesammelte Schriftenappeared at Hamburg (1829-1834) in 14 volumes, followed by 6 volumes ofNachgelassene Schriften(Mannheim, 1844-1850); more complete is the edition in 12 volumes (Hamburg, 1862-1863), reprinted in 1868 and subsequently. The latest complete edition is that edited by A. Klaar (8 vols., Leipzig, 1900). For further biographical matter see K. Gutzkow,Börnes Leben(Hamburg, 1840), and M. Holzmann,L. Börne, sein Leben und sein Wirken(Berlin, 1888).Börnes Briefe an Henriette Herz(1802-1807), first published in 1861, have been re-edited by L. Geiger (Oldenburg, 1905), who has also published Börne’sBerliner Briefe(1828) (Berlin, 1905). See also Heine’s witty attack on Börne (Werke, ed. Elster, vii.), G. Gervinus’ essay in hisHistoriche Schriften(Darmstadt, 1838), and the chapters in G. Brandes,Hovedströmninger i det 19 de Aarhundredes Litteraturvol. vi. (Copenhagen, 1890, German trans. 1891; English trans. 1905), and in J. Proelss,Das junge Deutschland(Stuttgart, 1892).
BORNEO,a great island of the Malay Archipelago, extending from 7° N. to 4° 20′ S., and from 108° 53′ to 119° 22′ E. It is 830 m. long from N.E. to S.W., by 600 m. in maximum breadth. Its area according to the calculations of the Topographical Bureau of Batavia (1894) comprises 293,496 sq. m. These figures are admittedly approximate, and Meyer, who is generally accurate, gives the area of Borneo at 289,860 sq. m. It is roughly, however, five times as large as England and Wales. Politically Borneo is divided into four portions: (1) British North Borneo, the territory exploited and administered by the Chartered British North Borneo Company, to which a separate section of this article is devoted; (2) Brunei (q.v.), a Malayan sultanate under British protection; (3) Sarawak (q.v.), the large territory ruled by raja Brooke, and under British protection in so far as its foreign relations are concerned; and (4) Dutch Borneo, which comprises the remainder and by far the largest and most valuable portion of the island.
Physical Features.—The general character of the country is mountainous, though none of the ranges attains to any great elevation, and Kinabalu, the highest peak in the island, which is situated near its north-western extremity, is only 13,698 ft. above sea-level. There is no proper nucleus of mountains whence chains ramify in different directions. The central and west central parts of the island, however, are occupied by three mountain chains and a plateau. These chains are: (1) the folded chain of the upper Kapuas, which divides the western division of Dutch Borneo from Sarawak, extends west to east, and attains near the sources of the Kapuas river a height of 5000 to 6000 ft.; (2) the Schwaner chain, south of the Kapuas, whose summits range from 3000 to 7500 ft., the latter being the height of Bukit Raja, a plateau which divides the waters of the Kapuas from the rivers of southern Borneo; and (3) the Müller chain, between the eastern parts of the Madi plateau (presently to be mentioned) and the Kapuas chain, a volcanic region presenting heights, such as Bukit Terata (4700 ft.), which were once active but are now long extinct volcanos. The Madi plateau lies between the Kapuas and the Schwaner chains. Its height is from 3000 to 4000 ft., and it is clothed with tropical high fens. These mountain systems are homologous in structure with those, not of Celebes or of Halmahera, but of Malacca, Banka and Billiton. From the eastern end of the Kapuas mountains there are further to be observed: (1) A chain running north-north-east, which forms the boundary between Sarawak and Dutch Borneo, the highest peak of which, Gunong Tebang, approaches 10,000 ft. This chain can hardly be said to extend continuously to the extreme north of the island, but it carries on the line of elevation towards the mountains of Sarawak to the west, and those of British North Borneo to the north, of which latter Kinabalu is the most remarkable. The mountains of North Borneo are more particularly referred to in the portion of this article which deals with that territory. (2) A chain which runs eastward from the central mountains and terminates in the great promontory of the east coast, known variously as Cape Kanior or Kaniungan. (3) A well-marked chain running in a south-easterly direction among the congeries of hills that extend south-eastward from the central mountains, and attaining, near the southern part of the east coast, heights up to and exceeding 6000 ft.
Coasts.—Resting on a submarine plateau of no great depth, the coasts of Borneo are for the most part rimmed round by low alluvial lands, of a marshy, sandy and sometimes swampy character. In places the sands are fringed by long lines ofCasuarina, trees; in others, and more especially in the neighbourhood of some of the river mouths, there are deep banks of black mud covered with mangroves; in others the coast presents to the sea bold headlands, cliffs, mostly of a reddish hue, sparsely clad with greenery, or rolling hills covered by a growth of rank grass. The depth of the sea around the shore rarely exceeds a maximum depth of 1 to 3 fathoms, and the coast as a whole offers few accessible ports. The towns and seaports are to be found as a rule at or near the mouths of those rivers which are not barricaded too efficiently by bars formed of mud or sand. All round the long coast-line of Dutch Borneo there are only seven ports of call, which are habitually made use of by the ships of the Dutch Packet Company. They are Pontianak, Banjermasin, Kota Bharu, Pasir, Samarinda, Beru and Bulungan. The islands off the coast are not numerous. Excluding some of alluvial formation at the mouths of many of the rivers, and others along the shore which owe their existence to volcanic upheaval, the principal islands are Banguey and Balambangan at the northern extremity, Labuan (q.v.), a British colony off the west coast of the territory of North Borneo, and the Karimata Islands off the south-west coast. On Great Karimata is situated the village of Palembang with a population of about 500 souls employed in fishing, mining for iron, and trading in forest produce.