730 



PENCIL. 



be roughly estimated at 130,000 Ibs., but young 

 trees are yearly coming into bearing to swell this 

 quantity; should the cultivation meet with no 

 serious interruption, it may perhaps in time sup- 

 ply the whole of the English market with spices. 



The government of Penang, Malacca, and Sin- 

 gapore, is subordinate to the presidency of Bengal. 

 As a commercial and maritime station Penang has 

 many advantages ; it serves as an entrepdt for the 

 various produce of China, the eastern islands and 

 straits, the native merchants from which take back 

 in return British and India goods. It was at one 

 time contemplated to form an extensive arsenal and 

 ship-building depot at Penang, and indeed several 

 fine ships were built there, but the object was ulti- 

 mately abandoned. At present Penang serves as a 

 rendezvous for our naval squadron in the Indian 

 seas, for which its position, healthiness, and abun- 

 dance of provisions, admirably qualify it. 



PENCIL, (a.) The marking material of what 

 are called black-lead pencils is plumbago, or gra- 

 phite, a compound of carbon and iron, in the pro- 

 portion of nine parts of carbon to one of iron. 

 This mineral is of a dark iron-black colour, passing 

 into steel gray. It occurs in a massy form, in kid- 

 ney-shaped lumps, varying from the size of a pea 

 to much larger lumps, and is found in beds of 

 quartz, and in masses of calcareous earth. It has 

 a glistening metallic lustre, and the fracture pre- 

 sents a texture somewhat between scaly and granu- 

 lar. The large masses are slaty in their appearance, 

 and occur generally in distinct concretions. It 

 takes a considerable polish by rubbing, and, as is 

 well known, gives a dark lead-gray streak when 

 drawn along paper or wood. It is unctuous to the 

 feel and not very brittle, and about twice as heavy 

 as its own bulk of water. The large quantity of 

 carbon which it contains, renders it peculiarly fitted 

 to the purposes of the chemist, in the form of 

 crucibles, as it will bear an intense heat. The 

 other purposes to which it is applied, are to relieve 

 friction in the axes and pivots of wheels. Its 

 power this way may be illustrated by rubbing a 

 button first on a plain board, five or six times, and 

 applying it to a bit of phosphorus, the latter will 

 immediately burn. When rubbed on a surface 

 covered with plumbago, double or treble the fric- 

 tion will be required to produce the same effect. 

 Plumbago is also used to give a polish to shot and 

 gunpowder, to give a preservative coating to cast 

 iron, and to mix with clay to form a lining for fur- 

 naces. At North Carolina shingles are coated with 

 a mixture of black lead and oil, which is said to be 

 an excellent preservation against fire. For all these 

 latter purposes, however, coarse and impure black 

 lead is employed. 



There is only one mine of plumbago in England. 

 It is situated at Borrowdale on the side of Seatal- 

 lor Fell, a lofty mountain in Cumberland, about 

 eight miles south of Keswick. 



In the reign of Elizabeth there was a mine of 

 copper and lead in the immediate vicinity, which 

 was worked by some Germans; but on finding 

 some small veins of gold and silver in the mine, a 

 contest arose with the crown as to who should pos- 

 sess the precious metals ; Elizabeth gained the 

 contest, and the Germans soon afterwards left the 

 country. About that period, however, the Bor- 

 rowdale black-lead mine was discovered, and soon 

 drew attention to its valuable contents. Its celeb- 

 rity gradually increased, and with it an extensive 

 system of purloining. Sometimes the workmen in 



a neighbouring mine would rut through into tlv? 

 black-lead mine and carry off quantities of the con- 

 tents. At another time a party of miners over- 

 came a guard placed at the entrance of the mine, 

 and kept possession of the whole place for several 

 days. An act of parliament was obtained in the 

 last century, inflicting severe penalties on all de- 

 predators, and since then an improved mode of 

 protection has been devised. 



The entrance to the mine is about 1000 feet 

 from the level of the ground, from which spot there 

 is an excavated cavity, extending G60 feet horizon- 

 tally into the body of the mountain ; this passage 

 has a railway laid along its whole length, and is 

 used to convey the ore from the bowels of the 

 mountain to the entrance. 



Mr Parkes, who visited the mine in 1814, gives 

 the following account of it : 



" There two entrances to the mine, a small 

 one by which the workmen descend by means of a 

 flight of steps, and the other is a large horizontal 

 one, capable of admitting hand-carts and wheel- 

 barrows for the removal of the rubbish and loose 

 earth by which the black lead is enveloped, and 

 through this entrance the water passes off which 

 constantly runs through the mine. In order to se- 

 cure the vast treasure which is contained within 

 this mountain, the proprietors have now erected a 

 strong brick building, consisting of four rooms on 

 the ground floor, one of which is immediately over 

 the opening by which the workmen enter the mine 

 as they go to their work. This opening is secured 

 by a trap door, and the room connected with it is 

 called the dressing room, for when the men enter 

 it, they strip off their usual clothes, and each of 

 them put on a dress suitable for working in a mine. 

 The men work six hours each, and then they are 

 relieved by others. As the black lead is cleaned, 

 it is put into firm casks which hold about one hun- 

 dred and twelve pounds each, and these are sent by 

 waggon to the warehouse of the proprietors in 

 London. Formerly, this mine was opened but once 

 in seven years: but in consequence of the demand 

 being greater, and the quantity which they have 

 discovered not being so large, it has been found 

 expedient to open and dig for ore during six or 

 seven weeks every year. During this time the 

 mine is guarded night and day. In consequence of 

 the mines having been opened in late years every 

 summer, they now raise all the black lead they 

 find, and then the mine is securely shut in the fol- 

 lowing manner: The workmen wheel back the 

 rubbish which had been removed at the opening of 

 the mine, and this is laid on in a continued heap, 

 to the amount of some hundred cart loads, which 

 securely blocks up both the passages into the mine. 

 The door is then locked as well as the door into 

 the house, and all the men thus leave the premises 

 in a state of safety; for the mass of rubbish which 

 is thus wheeled in at the large door, dams up the 

 small rill of water which usually flows through the 

 mine, and thus has the effect of flooding it com- 

 pletely. Thus, if an attempt were made to break 

 the house and enter the mine by that road, the 

 robbers would find that the water bad risen to such 

 a height as would drown any individual who should 

 attempt to search for the ore." 



Readers may be surprised at the extreme caution 

 displayed in every part of these processes, as de- 

 scribed by Mr Parkes, to prevent puiloining, &c., 

 but this surprise will cease when we recollect the 

 value of the ore ; the market price of the best 



