BORNEENE. 



BOROUGH-ENGLISH. 



200 



of a cylinder or barrel perfected, or a hole simply made in wood the 

 term boring is equally applied to all these operationa. 



Cannon are usually cast solid, and bored by machinery ; and in an 

 accommodated sense the term is applied to the similar operations by 

 which musket-barrels, the cylinders of steam-engines, and other articles 

 which are originally made hollow, have their inner surface turned to a 

 perfectly smooth surface and cylindrical shape. The boring instru- 

 ments of the carpenter consist of awls, which are put into soft wood, 

 with a rotatory motion, without removing or bringing away its sub- 

 staace ; gimlets and augers, which are supplied with cutting edges, and 

 are partially hollowed, to allow of the escape from the hole of the 

 detached particles of wood; and bits of various kinds, which also 

 remove the wood, and are applied with greater power and precision by 

 means of a crank-shaped instrument called a brace. Small holes in 

 metals are usually bored with drills, which are formed with scraping 

 rather than cutting edges, and are used either in a brace, a drill-stock 

 capable of imparting an alternating rotatory motion by means of a bow 

 worked by hand, or some other contrivance, or in a lathe. Boring 

 machines of the lathe character are too various and complex to be 

 described here. Suffice it to say, that the perfection to which they 

 have been brought, has rendered most essential service to science and 

 manufactures, and removed one of the greatest difficulties experienced 

 by early improvers of the steam-engine. 



The boring of Artesian wells is performed with various kinds of 

 chisels or jumpers, augers, and instruments suitable for extracting the 

 detached fragments, attached to the lower end of an iron rod formed of 

 many lengths screwed into one another; these instr- ments are either 

 turned round, or jumped up and down, or worked with a combination 

 of these two motions by suitable mechanism, the kind of tool employed, 

 and the mode of working, being varied from time to time as the 

 several strata are met with. 



Beart's boring tools, patented in 1844, are intended to be used in 

 circumstances where the hole made by the borer can be kept constantly 

 full of water. The borer itself is attached to a hollow tube instead of 

 a solid rod, and acts as one leg of a siphon ; the other leg being an 

 excavated channel prepared for the purpose, and kept full of water. 

 The arrangement of the several parts is such, that as fast as the frag- 

 ments of rock or soil are loosened by the borer, they are drawn up 

 with the water by which they become saturated, through the tube 

 which forms the stem or vertical rod of the borer : this, at least, is the 

 theory on which the inventor has founded his patent. 



At the meeting of the British Association in 1848, Mr. Vignolles 

 communicated an account of a method of boring Artesian wells, 

 invented by M. Fauvel of Perpignan. M. Fauvel had observed that in 

 several cases of success in boring for water ith solid iron rods, so 

 soon as the spring was tapped all the triturated particles were brought 

 up without the use of the auger. He inferred that if the boring could 

 be effected by a hollow tube about two inches less in diameter than 

 the width of the auger, communicating with an injecting force-pump 

 by a flexible tube from the surface, a result would follow similar to 

 that which resulted from the natural power of the rising column of 

 water. Having tested the hypothesis, he found that the well could be 

 bored in much less time than by the former method. The plan has 

 since been largely adopted, in some cases to very great depths. 



An attempt was made by Mr. Card, of Calstock, in 1848, to produce 

 an improved boring-machine, to effect in another way the objects 

 intended by Mr. Beart in England, and M. Fauvel in France. His 

 boring-machine consists of a hollow cylinder, to the bottom of which 

 the boring-bit is attached in a peculiar way ; and as the rock or earth 

 is bored, the fragments force themselves up into the cylinder, where 

 they are retained by a valve. The cylinder does not reach to the top 

 of the bore, but requires to be raised when full, in order that it may 

 be emptied ; it, however, will contain so large a quantity, that the 

 necessity of raising it will occur much less frequently than under the 

 unual system. Instead of joining successive lengths of rod to the 

 boring tool, the latter is raised and lowered by a chain. 



At a meeting of the Cornwall Polytechnic Society, a few years ago, 

 Mr. Prideaux proposed the adoption of a chemical means of facilitating 

 the process of boring. He found that a stream of hydro-oxygen gas 

 applied to a piece of granite stone produced heat ; and that on the 

 application of cold water the stone became soft, and yielded to the 

 tool. Oxygen might be superseded by common air from a pair of 

 double bellows; and common coal-gas might be used instead of 

 hydrogen. 



A very instructive illustration of the apparatus employed in well- 

 boring may be studied at the Museum of Economic Geology. 



BORNEENE. [CAMPHOR.] 



BOKNEOL. [CAMPHOB.1 



BORNEO-CAMPHOR [CAMPHOR.] 



BuROFLUORIC ACID. [FLCOBORIC ACID.] 



BORON (B), an elementary body, and one of the constituents of 

 boracic acid, oxygen being the other. This substance was first obtained 

 by Davy in 1807, and he procured it by exposing slightly moistened 

 boracic acid, placed between two surfaces of platinum, to the action 

 of a Voltaic battery ; a dark-coloured substance separated on the nega- 

 tive plate, to which he gave first the name of buracium, supposing it 

 would be found to be metallic ; but having afterwards ascertained it to 

 be more analogous to carbon than to any other substance, he called it 



XBTS ASD sci. Dry. VOL. n. 



boron. In this way however little boron was obtained, and its pro- 

 perties were imperfectly examined till 1808, when Gay Lussac and 

 Thenard procured it in larger quantity by heating boracic acid with 

 potassium in a copper tube ; by this metal the oxygen was separated 

 from the boron, potash was formed, and boron developed ; and the 

 residue of the operation being washed first with water, and then with 

 dilute hydrochloric acid, the boron remains. It is more economically 

 obtained by decomposing an alkaline borofluoride by potassium ; for 

 this purpose liquid hydrofluoric acid is to be saturated with boracie 

 acid, and the solution neutralised by carbonate of potash ; the salt pre- 

 cipitated is to be well washed with cold water, and dried at nearly a red 

 heat ; it is then mixed with an equal weight of potassium, and the mix- 

 ture heated to redness in a covered iron crucible ; the residual mass 

 will be found to consist of boron mixed with fluoride of potassium ; 

 the fluoride is dissolved out from the boron by washing with water 

 containing a little chloride of ammonium. The decomposition that 

 takes place is expressed in the following equation : 



KF, BF S + K 3 = 4KF + B 



' v ' Potassium * v ' Boron 



Borofluoride Fluoride of 



of potassium potassium 



Boron is a powder of a deep brown colour with a shade of green ; and 

 when it has been heated in vacua or in gases which contain no oxygen, 

 it is insoluble in water ; and is not dissolved by alcohol, ether, or oils, 

 whether hot or cold. It is devoid of smell and taste. It is not altered 

 by exposure to the air or to oxygen gas at the usual temperatures ; 

 but when heated to about 600 it absorbs oxygen, and, burning with 

 considerable brilliancy, is converted into boracic acid ; a portion how- 

 ever of the boron is so enveloped by the acid formed, that it is 

 impossible to burn the whole of a given quantity of boron at one 

 operation. 



Boron does not decompose water at a boiling temperature. Its 

 density when recently prepared is 1'183, but when it has been exposed 

 to a strong heat in close vessels its density is increased to V844, and it 

 suffers no other change, being neither fused nor volatilised. It may be 

 melted however by the heat of a powerful galvanic battery. It is a 

 non-conductor of electricity ; the alkalies and acids produce no effect 

 upon it, except the nitric, which it decomposes, and the boron, by 

 acquiring oxygen, is converted into boracic acid. It has a greater 

 affinity for oxygen than carbon, setting the latter element free when it 

 is fused with carbonate of potash. 



Prepared by the above method, boron is quite amorphous. Accord- 

 ing to Professor Wohler and M. Deville it may be obtained in the 

 crystalline condition by fusing boracic acid with 80 per cent, of the 

 metal aluminium in a powerful furnace. The boracic acid is reduced 

 by a portion of the aluminium, the remainder dissolving the boron, 

 which separates out on cooling in transparent garnet-red crystals of 

 high lustre and refractive power. 



Crystallised boron is exceedingly hard. It scratches corundum and 

 even sapphire with ease. A crystal may be crushed with a diamond, 

 but the latter is marked and slightly damaged by the operation. It 

 cannot be fused alone by any known means ; it resists the action of 

 oxygen at a far higher temperature than the amorphous variety, even 

 nitrate of potash being without action upon it at a red heat. 



Graphitic boron is the name given to that form of the element 

 obtained when borofluoride of potassium is decomposed by aluminium 

 at a high temperature with a flux of the chlorides of potassium and 

 sodium in equivalent proportions. It may be quite freed from alumi- 

 nium by digesting in hydrochloric acid. It presents a close resem- 

 blance to ordinary graphite, that modification of carbon intermediate 

 between charcoal and diamond. Its appearance is also very similar to 

 graphitic silicon, thus establishing the intimate and interesting physical 

 analogy that exists between these three elements. 



Boron combines with various elementary bodies, forming with the 

 metals compounds which are termed borides. 



Hydrogen and Boron. It appears that, under peculiar circumstances, 

 hydrogen is capable of dissolving a small portion of boron ; but no 

 definite compound to which the term boride of hydrogen could be 

 applied is known. 



Oxygen and Koran unite, and only in one proportion ; the compound 

 is described under BORACIC ACID. 



Baron and Nitrogen. Boron decomposes nitric oxide at a red heat, 

 boracic acid and nitride of boron (BN) being formed. The latter is a 

 white, light, amorphous powder. Heated with caustic potash, it yields 

 ammonia, borate of the alkali being at the same time produced. 



Boron and Sulphur form sulphide of boron (BS 3 ), but the compound 

 possesses no interest. 



Boron and Chlorine unite with considerable energy when the former 

 is heated to redness and plunged into an atmosphere of the latter gas. 



Baron and Fluorine combine. [FtuoBOHlc ACID.] 



BOROUGH-ENGLISH is a customary descent of lands or tenements, 

 whereby, in all places where this custom holds, lands and tenements 

 descend to the youngest son ; or if the owner of land have no issue, 

 then to the youngest brother ; as in Edmonton, some parts of Rich- 

 mond, and other places : and the reason of this custom, says Littleton, 

 is, for that the youngest son is presumed in law to be least able to 

 shift for himself. 



