490 



1'ULTUSK 



PUMPS 



l-i-hop'g seat, ami is fHinouH as the scene of Charles 

 XII. 'a defeat by Peter the lireat on '-'Till June 1709. 



I'lillnsk* a town of Poland, 32 miles N. of 

 \\ 'ursaw. Tlere Charles XII. of Sweden defeated 

 Hi'- Saxons in 1703, and here, too, on December 26, 

 1N06, was fought a fierce battle lietween the 

 Kussians and the French, the latter being ulti- 

 mately victorious. The town was destroyed by 

 fire in 1875. Pop. 19,946. 



Pnlvrrmarher'H Chains. See ELECTRICITY 



Puma, or COUOUAR (Ftli* concolor), a large 

 Carnivore distributed in North and Smith America 

 In-tween 60 N. and 50 S. lat., but rare in those 

 parts which have been long settled. It is some- 

 times called the American 'lion,' 'panther,' 

 ('painter'), or 'catamount,' and is about the 

 size of a leopard. The fur is thick and close, 

 dark yellowish red above, lighter on the sides, 

 and reddish white on the tally ; the muzzle, 

 chin, throat, breast, anil inside* of the legs are 

 more or less white. But the colouring varies a 

 little in different localities. Young pumas have 

 dark-brown sjiots in three rows on the back, and 

 scattered markings elsewhere. The long tail is 

 covered with thick fur, ami is slight Iv coiled. The 

 pumas have very diverse haunts the forest, the 

 DMh, nnd the grassy pampas; they have no fixed 

 lairs, but roam about by night from place to place 

 in starch of prey. They are agile in their move- 

 ments, and can leap and spring well, but swim only 

 iiinliT fiiniinilsioii. M:my kinds of mammals fall 

 vi.-tims to the pumas, and they are the more 

 disastrous to flocks and herds because of their 

 habit of killing many more than they devour. To 

 the booty which they have secured but merely 

 tasted they will afterwards return. They rarely 

 attack man, but one puma has been known to 

 kill fifty sheep in a night, drinking a little of the 

 blood of p;ieh ; hence their extermination in many 

 regions. The two sexes live apart, but pair in 

 winter ami summer. Two or three young are horn 

 at once, and are left a good deal to themselves, 

 though after the first birth tl ...... others are cer- 



tainly affectionate. In spite of its restless and 

 voracious instincts the puma may lie readily tamed, 

 and is -aid to In-come gentle. The skin is some- 

 times ii-cd, and the flesh is occasionally eaten. 



l'llllli< > < > . a general term for the cellular, spongi- 

 form, filamentous, or froth-like parts of lavas. 

 This highly jKirons and froth like structure is due 

 to the abundant escape of vapours through the rock 

 while it was in a state of fusion. I'nder the micro- 

 scope the rock is seen to lie a glass, crowded with 

 minute gas or vapour cavities and abundant crys- 

 tallites. Owing to its porous structure pumice 

 readily floats in water. It is usually a form of 

 some highly acid lava, such as obsidian : but now 

 and again lix-ic lava- give ri-e to pumice (Canary 

 Islands, Hawaii). The latter is dark brown or 

 black, and often shows metallic tarnish ; the 

 former, which is much the more common, is white 

 or gray, and sometimes yellow. It is a hard but 

 brittle rock, ami is much used for polishing wood, 

 ivory, metals, glass, slates, marble, lithographic 

 tones, &c , in preparing vellum and parchment, 

 and for rubbing away corns and callosities. 

 lireat quantities are exported from the I.ipari 

 Isles ; ami tluit from the quarries in the Peak of 

 T'-ncrifl'e, 2<MM> feet alxive sea-level, is lietter and 

 cheaper. Pumice occurs as the crust of some kinds 

 of lava, and is often ejected in the form of loose 

 cinders during volcanic, eruptions. Sometimes im- 

 mense quantities are thrown into the sea and are 

 often floated for great distances. Eventually the 

 cinders get water-logged and sink to the liottom. 

 Abundant fragments were dredged up from abys- 



mal depths by the Challenger expedition. After 

 the eruption and earthquake in the Straits of 

 Sunda in 1XS3, the seaport of Folok Batoung WM 

 closed with a liarrier of pumice 19 miles long, two 

 thirds of a mile broad, and from 13 to 16 feet deep. 



I'limiHTllirkrl. a kind of i ve-bread (made of 

 unttolteif flour), much used in Westphalia. The 



etymology is disputed. 



Pumpkin. See GOURD. 



I'limps. machines for lifting liquids to a higher 

 level, include ( 1 ) the Lift or Suction Pump, (2) the 

 Lift and Force Pump, (3) the Pulsometer, (4) the 

 Chain-pump, (5) Spiral Pumps, (6) the Centrifugal 



Pump, (7) the Jet-pump, (8) the Persian \\ I I, 



(9) Scoop-wheels. 



( 1 ) The Lift or Suction Pump (fig. 1 ). A is the 

 cylinder ( the ' barrel '), closed or open at t he top; 

 li is a pipe (the 'suction-pipe') communicating 

 with the water to be raised ; C is a ' discharge- 

 pipe,' which may l>e reduced to a mere spout; D 

 is a valve, opening up- 

 wards only ; E is another 

 valve, also opening up- 

 wards only, and borne by 

 F ; F is the ' bucket,' a 

 hollow cylindrical piece of 

 wood or metal which is 

 made, by leather or by 

 hemp or other packing, to 

 fit the barrel just so 

 closely that water cannot 

 travel between the bucket 

 and the barrel ; CJ is the 

 piston-rod, driven by hand, 

 steam, windmill, or animal 

 power, and moving the 

 bucket up and down in 

 the barrel. Each upward 

 stroke of the piston at 

 first lifts air, of which 

 none can travel back past 

 the bucket ; a partial 

 vacuum is produced in I! ; 

 water ascends in 1! until 

 the external atmospheric 

 pressure is balanced by the 

 partial atmospheric pres- 

 sure below D plus the 

 weight of the water col- 

 umn in B ; as F now 

 descends, air gets to the 

 upper side of the valve, 



Fig. 1. 



pper 



and is lifted on the upstroke, and so on ; 

 that, if the valve D lie not more than at most 33 

 feet above the water below (in practice 25 feet 

 or less), water will be, step by step, pushed up 

 B by the external atmospheric pressure until tin- 

 valve D is underwater; thereafter the succeeding 

 strokes of the pump operate on the water aliove D 

 and force it into the discharge-pipe, C, the external 

 atmospheric pressure keeping the space below 1) 

 filled with water. The power expended is applied 

 (1) in lifting water ; (2) in overcoming the pump- 

 friction ; (3) in overcoming t he water friction ; ami, 

 (4) where the pump is ill-shaiicd, in producing 

 eddies and broken water. A lift -pump must In- 

 very carefully proportioned and const meted in 

 order to utilise, in water-lifting, one-half of the 

 whole power expended in working it. Such pumps 

 must work slowly, so that the valves may close 

 properly ; and an air-vessel is, if C lie not a mere 

 spout, required on C so as to minimise shock and 

 render the outflow less intermittent, by the com- 

 pression and elastic expansion of the air contained 

 in it. The outflow is also regulated by driving 

 two or three pumps off the same shaft and properly 

 timing their relative motions. 



