PEAR-GAGE. 



PEARL-FISHERY. 



be strictly adopted in this country with advantage, owing to the 

 rkhncM of the soil and moisture of the climate, circumstance* which 

 mra favourable to the production of shoots rather Uuui fruit-bud*, and 

 this Uodency U farther encouraged by shortening the shoots to the 

 Bxuwt which the French recommend. In both these modee tiers of 



branche> proceed from a central uteni ; in the pyramidal form the 

 branches are horixuuUl, each tier being successively shorter than 

 the one below, in the Quenouille the branohee are curved down- 

 ward*, and thu mode might be uoo*snfully practised in thi* country, 

 by leaving the abooU at full length, care being taken that all upright 

 ahoota are ahortened in summer. 



The pruning of standard pear-trees U usually confined to the winter 

 regulation of the brauche* by thinning, and ahortening where the sub- 

 division of branchea is desirable or where they are too weak. Wall 

 and eapalier tree* require both a summer and winter pruning. In 

 summer a number of ahoota will be produced beyond that which will 

 be required for training. If theae are allowed to grow without inter- 

 ruption during a considerable part of the season, and then at once 

 cleared away, the tree is apt to receive a shock from which it does not 

 soon recover. If the shoots are shortened too much or too early, the 

 buds, which would otherwise have proved blossom buds in the follow- 

 ing spring, will immediately become excited (other channels for the 

 flow of sap being cut off), and bunt into shoots. [MouruoLouT.] 



In order to avoid this, which is a case of frequent occurrence, a 

 portion of these superfluous shoots should be first stopped at an early 

 period, and afterwards another portion : by the middle of June part of 

 them may be cut back to within two or three inches of their base ; and 

 thus by degrees the whole will be ultimately reduced, without any 

 great or sudden derangement of the general flow of the sap. The 

 winter pruning is attended with less vital danger to the tree. It 

 consists chiefly in shortening spurs to the lowest fruit-buds and 

 judiciously thin t H n g them. 



If borders are well made, there will be lea* occasion for raising the 

 trees after they have been once planted. Still, aftr four or five years, 

 it will, under all circumstances, prove advantageous to remove the 

 trees from the wall, trench the border, and replant, spreading the 

 roots near the surface in a horizontal direction, or inclining slightly 

 downwards. Cutting the roots, without entirely removing the tree, is 

 attended with the disadvantages arising from the partial loosening of 

 the toil, and the difficulty of reaching the perpendicular portions of 

 the root. 



PEAR-GAGE. The principle of Smeaton's pear-gage, for measuring 

 the exhaustion of a receiver, by means of the AIR PUMP, differs from 

 that of the other gages, in that the measurement does not take place 

 until after the air has been re-admitted into the receiver. Suppose a 

 wire working through a collar in the top of the receiver and supporting 

 a tube open only at the lower end. Under the tube U a cup of 

 mercury, standing on the floor of the receiver, so that by lowering the 

 wire the open end of the tube may be immersed in the mercury. The 

 exhaustion being made before lowering the wire, the air in the tube 

 will be rarefied equally with that in the rest of the receiver. If the 

 wire be then lowered, and the air re-admitted into the receiver, the 

 mercury will rise in the tube until the elastic force of the recom- 

 pressed air in the tube, together with the column of mercury, 

 counterbalances the pressure of the external air. A gage attached to 

 the tube shows, by the height of the mercury, what was the original 

 rarefaction. 



Now it U plain that while the ordinary gages show the actual 

 amount of elastic force left in the receiver, the pear-gage submits the 

 air, or whatever else there may be, to a process of compression before 

 the measurement U made. If there be nothing but air, all the gages 

 agree ; but if, as generally is the case, there be also vapour, the pear- 

 gage show* a much higher degree of apparent exhaustion, than the 



PEAKLASH. [POTASSIUM.] 



PEARL K1S1IKKY. The fisheries which are carried on to supply 

 the market of the world with pearls are numerous, and some of them 

 are of very ancient date. The fishery at Catifa in Arabia, which pro- 

 duced the pearl bought by Tavernier for 110,0002., was celebrated in 

 Pliny's time. In the Old World, the west coast of Ceylon, that of 

 Corouundel, and the Persian Gulf, are among the more prominent 

 tarttoBT The Algerine coast and the Sooloo Islands also furnish a 

 certain share. In the New World, the neighbourhood of St. Margarita, 

 or Pearl Island, and other localities on the coast of Colombia, furnish 

 a great many, and the Bay of Panama also contributes considerably ; 

 but the pearls from the Western work), though many of them are 

 large, cannot be compared with those of the East in shape, colour, and 

 general beauty. 



The Bahrein Islands (Persian Gulf) give a most abundant harvest of 

 these beautiful molluscous secretions ; perhaps the most abundant in 

 the world. Sixty thousand toinauus of Bassorah, about 90,000(. sterling 

 of our money, and often more, are derived from the fishery in about 

 two months, the time during which it lasts, the commencement being 

 in June. There is no monopoly ; any one may engage in the adventure 

 upon payment of a tax on the produce to the government. The 

 Persians principally are engaged in it, and the divers are of that 

 .-.. n. 



The Western pearl fisheries, especially those on the coast of Colombia, 



must have been very valuable once. Seville alone is said to have im- 

 ported upwards of 697 Ibs. in the year 1587- The second Philip's 

 celebrated pearl, which weighed 2fiO carats, and was valued at 150,000 

 dollars, came from Margarita. These prUes were not forgotten in 

 1825, when joint-stock companies raged. One company undertook the 

 prosecution of the Colombia fishery, and another embarked in that of 

 Panama and the Pacific, both with about the same success; !>: in 

 1826 they were abandoned. Some fine specimens of the shells of 

 Mollusc* were sent home by one of them. The Algrrim* ground waa 

 also, we believe, undertaken by an English company in 1820. 



The pearl* which are the objects of these fisheries are found in the 

 shells of MtUayriita, or pearl-oysters, as they ore called, and principally 

 in those of the species named Arirula or Mdeagrina mar-ja, 

 The best ground is considered to range at depths varying from 6 to 8 

 fathoms ; and the divers, who usually are unhealthy and short-lived, 

 are said to be able to remain generally from a minute to a minute and 

 a half under water. Two minutes, four, and even six, have been men- 

 tioned; but constructed as the human respiratory and circulating 

 system is, we should think the last-mentioned periods must be very 

 rare. A submersion of a minute and a half is calculated to do mis- 

 chief enough in ordinary cases. 



Ceylon affords a good example of the commercial system under which 

 the ]>earl-fishery is carried on. The bay of Condateuy is the most 

 central rendezvous for the boats employed in the fishery. The banks, 

 where it is carried on, extend several miles along the coast fn>:n 

 Mauaar southward off Arippo, Condatchy, and Pouiparipoo. The 

 principal bank U opposite to Condatehy, and lies out at sea about 

 twenty miles. After the survey of the state of the beds and the con- 

 sequent report to government, the particular banks to be fished are 

 put up for sale to the highest bidder, and are usually purchased by a 

 native merchant. The government however sometimes judges it more 

 advantageous to fish the bonks on its own account, and to dispose of 

 the pearls to the merchants. The banks are divided into three or four 

 different portions, which ore fished annually in succession. These 

 portions are completely distinct, and are set up separately to sole, each 

 in the year in which it is to be fished. A sufficient interval is thus 

 given to the oysters to attain their proper growth ; and aa the portion 

 first used has generally recovered its maturity by the time the last 

 portion has been fished, the fishery becomes almost regularly annual, 

 and may thus be considered SB yielding a yearly revenue. The oysters 

 are supposed to attain their complete state of maturity in seven years. 

 The fishing season commences in February, and ends about the begin- 

 ning of April. The period allowed to the merchant to fish the bonks 

 is six weeks or two mouths at the utmost ; but there are several inter- 

 ruptions which prevent the fishing days from exceeding more than 

 about thirty. If it happen to be a very bad season, and many stormy 

 days intervene during the period allotted, the purchaser of the 

 fishery is often allowed a few days more. Previous to the commence- 

 ment of the fishery, oil the boats rendezvous at Condatchy, and it is 

 here that they are numbered and contracted for. They regularly sail 

 out and return together. They reach the banks before day-break, and 

 at sun-rise commence fishing. In this they continue busily occupied 

 till the sea-breeze, which arises about noon, warns them to return to 

 the bay. When the boats come to land, their cargoes are immediately 

 token out, as it is necessary to have them completely unloaded before 

 night. Each boat carries twenty men, with a tindol, or chief boatman, 

 who acts as pilot. Ten of the men row and assist the divers in re- 

 ascending. The other ten are divers ; they go down into the sea by 

 five at a time ; when the first five come up, the other five go down ; 

 and by this method of alternately diving, they give each other time to 

 recruit themselves for a fresh plunge. In order to accelerate the 

 descent of the divers, large stones are employed. Some of the divers 

 use a stone shaped like a half-moon, which they fasten round the belly 

 when they mean to descend, and thus keep their feet free. They fear- 

 lessly descend to the bottom in from four to ten fathoms water in 

 search of the oysters. The diwr, when he is about to plunge, seizes 

 the rope to which one of the stones is attached, with the toes of his 

 right foot ; while he takes hold of a bag of net-work with those of his 

 left. He seizes another rope with his right hand, and holding his 

 nostrils shut with his left, plunges into the water, and by the assist- 

 ance of the stone speedily reaches the bottom. He then hangs the 

 net round his neck, and with much dexterity and all possible despatch 

 collects as many oysters as he con while he is able to remain under 

 water. He then resumes his former position, makes a signal to those 

 above by pulling the rope in his right hand, and is immediately l.y 

 this means drawn up and brought into the boat These men will 

 often make from forty to fifty plunges in one day, and at each plunge. 

 bring up about a hundred oysters. Some rub their bodies over with 

 oil, and stuff their ears and noses to prevent the water from entering ; 

 while others use no precautions whatever. The chief horror and 

 danger awaiting the diver are concentrated in the ground-shark. This 

 animal is a common and fearful inhabitant of all the seas in these 

 latitudes : and its terrors ore so continually before the eyes of the 

 divers, that they seek a vague safety in supernatural means. 



The divers ore paid differently, according to their private agreement 

 with the boat-owners, either in money or with a proportion of the 

 oysters caught, which they take the chance of opening on their own 

 account : the latter is the method most commonly adopted. The 



