PILCOMAYO 



PILES 



177 



are 6 fathoms in ilcpth. and the meshes are usually 

 thirty-six to thirty-eight to the yard. The mesh of 

 the nets used on the French coast is much smaller, 

 not exceeding fths of an inch square. The smallest 

 seines used at St Ives are 160 fathoms long, with a 

 depth of 8 fathoms at the centre, and 6 fathoms 

 at the wings ; the meshes are fths of an inch 

 square. In the seine the fish are not meshed : if 

 they were they would cause the net to sink. There 

 are only six 'stations ' or places tit for hauling the 

 seine at St Ives, and over two hundred seines. The 

 nets are therefore divided into groups, and each net 

 has to await its turn at the station to which it 

 belongs. The regulations of the fishery are con- 

 tained in the Sea-fisheries Act, 1868, 31 and 32 Viet. 

 chap. 45, sect. 68. The seine-fishery is carried on 

 principally between August and Christmas. Most 

 of the pilchards landed in Devon and Cornwall are 

 salted for the Mediterranean market, especially 

 Italy. They were formerly cured dry, the fish 

 lieing piled in heaps with salt on a floor, and the 

 brine and oil draining away from them constantly. 

 After remaining thus about a month the fish were 

 sifted from the salt, washed, packed in barrels, and 

 subjected to pressure which forced more oil from 

 them. Rut at present the salting is carried out in 

 watertight vats, so that the brine formed rises 

 over the fish, and they are kept steeped in the 

 liquid for several weeks or months. They are 

 then washed, packed, and pressed as before, the oil 

 lieing collected and sold principally for the use of 

 leather-dressers. This wet process produces much 

 cleaner and brighter-looking fish than the old dry 



Iiroces*. Twelve thousand to fifteen thousand hogs- 

 leads of these cured pilchards are annually ex- 

 ]K>rteil to the Mediterranean, each hogshead con- 

 taining from aVX) to 3000 fish, and weighing 476 Ib. 



gross. A large number of pilchards are also used as 

 bait for long line and hand line fishing, and a good 

 many are eaten fresh locally or in distant markets. 



Unlike herrings, the pilchards which are captured 

 are not in breeding condition, but are fat, with 

 small reproductive organs. In fact the habits of 

 the pilchard are the direct converse of those of the 

 herring. The pilchard is found feeding near shore 

 in more or less abundance for nine months of the 

 year, but in June, July, and August, when as a 

 rule none are being caught near shore, spawning 

 pilchards are found at some distance, 10 to 50 miles 

 or more, from the land. At this season a few are 

 oee.-isionally taken in mackerel nets, in which the 

 largest ones are meshed in consequence of their 

 swollen condition. The ova, unlike those of the 

 herring, are quite transparent, and buoyant like 

 those of the cod ami mackerel ; they pass through 

 their development while suspended separately in 

 the sea-water. Like the herring, the pilchard 

 feeds upon minute Crustacea and other animals, 

 some adult, some larval, which swartn in the sea. 



The principal foreign fisheries are at Concarneau 

 and other places in the Bay of Biscay, the mouth 

 of the Tagus in Portugal, and Marseilles, Nice, 

 and other |M>rts in the Mediterranean. In Scotland 

 the pilchard is known as the '////</ llrrrintj, Garvie 

 ll> i ,,,!'/ ( the sprat being Garvie), or Crue Herring. 



Pilroiiiityo. a river of South America, which 

 takes its rise in two branches in the Bolivian 

 Amies, in the department of Potosf, flows in a very 

 winding course south-east through the Gran Chaco, 

 rating Paraguay and Argentina, and finally 

 oms the I'io Paraguay a little below Asuncion. 

 ts length is said to lie 1700 miles, but this is mere 

 guess-work, as no one yet has explored its entire 

 course, and what is known of it is too tortuous for a 

 basis on which to estimate the whole. The volume 

 of water brought down is comparatively insignifi- 

 cant, much lieing spent in lagnnes on its way ; 

 at the mouth there is scarcely any perceptible cur- 

 376 



i 



rent, and the breadth is not 60 yards, while within 

 the first 200 miles it narrows more than once to less 

 than 20 yards, and moreover divides into branches, 

 among some of which explorers, like Captain Page, 

 have lost their way. There have been many 

 attempts, all fruitless, made to open the river 

 route oetween Argentina and Bolivia ; since 1556 

 a score of expeditions have been sent out, and 

 many of the explorers have perished. Some have 

 obtained 6-feet soundings for 255 miles from the 

 mouth, but then came rapids, where the river was 

 not more than 2 feet deep ; the upper stream, too, 

 is rendered impassable ov numerous rapids, and 

 lonjj canals would be required to open the river to 

 navigation. In its upper course its sands are auri- 

 ferous and the banks fertile ; lower down the valley 

 is swampy. The river's water is rendered like 

 brine by the great salt lakes of the Chaco in 

 which part the river is buried for hundreds of 

 leagues in a great forest of fan-palms. 



Piles are usually squared logs of wood used in 

 engineering operations, such as dams, bridges, and 

 roads (see COFFERDAM, &c.) They are sharpened 

 at the point, and, if necessary, protected with iron 

 points, to enable them to cut through the strata 

 they encounter as they are driven into the ground. 

 Piles are also used for permanent works, when 

 they are driven through loose soil till they reach a 

 firm liottom, and thus form a foundation on which 

 buildings, roads, &c. may be placed. Cast-iron is 

 also used for piles, which are cast hollow. Common 

 piles are driven in by machines called pile-drivers. 

 In these a heavy weight (or monkey) is raised to 

 a considerable height lietween two guides, and then 

 let fall on the head of the pile. The application of 

 steam to these drivers has made them very power- 

 ful engines Nasmyth's steam-hammer being a 

 well-known instance. See also LAKE-DWELLINGS. 



Piles, or HEMORRHOIDS, are small tumours 

 situated either within or on the verge of the anus. 

 The first step in their development is the dilata- 

 tion of one or more veins in this region. They 

 consist of folds of skin or mucous membrane, with 

 the subjacent tissues in an inflamed, infiltrated, or 

 permanently thickened condition, and usually con- 

 tain enlarged veins, though these sometimes become 

 obliterated. There are several varieties of these 

 tumours. Sometimes the pile is mainly composed 

 of a little knot of varicose veins ; in this case it is 

 readily emptied by pressure of the fluid blood con- 

 tained in it, which, however, returns when the 

 pressure is removed. Sometimes the blood coagu- 

 lates, either in a dilated vein, or, if this has given 

 way, around it, forming a solid tumour surrounded 

 by tissues thickened in consequence of inflamma- 

 tion ; or the tumour may consist of a kind of erec- 

 tile tissue formed by an abnormal condition of the 

 vessels of the mucous membrane ; this variety is 

 especially liable to bleed. These tumours are 

 divided into Ueedniij and blind piles, according as 

 they are or are not accompanied with haemorrhage ; 

 and into intermit and external piles, according as 

 they are within or without the sphincter muscle of 

 the anus. 



The following are the general symptoms of this 

 affection. The patient, after having experienced 

 for a varying time a feeling of heat, fullness, and 

 dull pain about the lower part of the bowel, becomes 

 conscious of a sensation as if there were a foreign 

 body in the anus, and on examination after an 

 evacuation discovers a small tumour, usually about 

 the size of a grape, which either remains outside 

 or is retracted*, according as it originated without 

 or within the sphincter. This tumour gradually 

 increases, and others form around it, until a mass 

 at length results as large as a pigeon's egg, or 

 larger. In its ordinary indolent state the tumour 



