J. J. Kraszewski (1812-1887), 

 historian, poet, dramatist, pub- 

 licist, and novelist, his works 

 actually exceeding 600 vols. in 

 number. Of the many writers of 

 merit Poland produced in recent 

 years the great commanding figure 

 was that of Henryk Sienkiewicz 

 (</..), a novelist of the highest 

 rank. Other men of note were 

 Milkowski, a vivid stylist who 

 wrote novels of the Balkans ; 

 Korzeniowski, a dramatist of real 

 life ; ^Alexander Glowacki, a hu- 

 morist of the type of Dickens ; 

 Pszybiszewski, a playwright of 

 originality, whose Homo Sapiens 

 made a great sensation ; and 

 Tetmaier, author of the novel, 

 Angel of Death. 



Robert Hachray 

 Bibliography. Poland : A Study 

 of the Land, People, and Literature, 

 VV. R. Morfill, 1893; The Partition 

 of Poland, Lord Eversley, 1915; 

 Poland as a Geographical Entity, 

 W. Nalkowski, 1916 ; Geographisch- 

 Statistisches Atlas von Polen, E. 

 von Homer, 1916; Poland Past and 

 Present, J. H. Harley, 1917; A His- 

 tory of Poland, F. E. Whitton, 1917 ; 

 Poland, authorised Eng. version of 

 Petite Encvclop6die Polonaise, ed. 

 E. Piltz, 1919 ; Poland and the 

 Poles, A. B. Boswell, 1920 ; Peace 

 Handbooks, vol. 8, P. and Finland, 

 pub. H.M. Stationery Office, 1920. 



Polar Exploration. General 

 term for the early voyages of dis- 

 covery in the Polar regions of the 

 Arctic and Antarctic Oceans and 

 for the later attempts to reach the 

 North and South Poles. See Ant- 

 arctic Exploration ; Arctic Ex- 

 ploration ; Scott, R.F. ; Shackleton. 



Polaris. Name given to Alpha 

 Ursae Minoris or the pole star, the 

 nearest star to the North Pole of 

 the heavens. See Pole Star. 



Polarisation of Light. An 



ordinary ray of light may be 

 thought of as an axis, about which 

 very small electro-magnetic vibra- 

 tions are being executed at an ex- 

 ceedingly rapid rate, and in every 

 possible direction perpendicular to 

 that of the ray. Thus, in the case 

 of a vertical ray of ordinary light 



the vibrations are all horizontal, 

 but may be directed to any point 

 of the compass. The polarisation 

 of light involves the reduction of 

 these haphazard and disorderly 

 vibrations to a more regular system. 

 The simplest type of polarisa- 

 tion is " plane polarisation," in 

 which all the vibrations along the 

 ray are in the same plane ; in the 

 case of a vertical ray of plane 

 polarised light the vibrations 

 would all be horizontal and all in a 

 given direction, e.g. the N.-S. 

 direction. A ray of light may also 

 be circularly polarised, in which 

 case the vibrations are executed in 

 circles about the axis of the ray. 

 The phenomenon of polarisation 

 may be obtained very simply by 

 passing an ordinary ray of light 

 through a crystal of tourmaline or 

 Iceland spar. One of the most re- 

 markable properties of light, clearly 

 showing its electro-magnetic nature, 

 is the fact that the plane of polari- 

 sation can be rotated by the pres- 

 ence of a strong magnetic field. 

 The passage of the ray through 

 certain substances, such as quartz 

 and various solutions, also causes 

 a rotation of the plane of polari- 

 sation. See Crystallography ; 

 Light ; Optics. 



Polariscope. Optical instru- 

 ment for exhibiting the properties 

 of polarised light. It consists 

 essentially of two parts, the polar - 

 iser and the analyser, of which the 

 first isolates the polarised beam, 

 while the second enables us to 

 observe its properties. The instru- 

 ment may take various forms, 

 according as the light is polarised 

 by passage through a crystal or by 

 reflection. The figure shows dia- 

 grammatically a standard polari- 

 scope. A is the polariser, B and D 

 quartz disks, C glass tube with 

 brass ends, in which is placed the 

 solution being examined. The two 

 quartz plates E can slide over one 

 another, a screw and wheel, F, 

 making the necessary adjustment. 

 G is a Nicol prism, H and J regu- 

 lator quartz plate and prism respec- 

 tively. K and L are lenses, M a 

 small telescope 

 to enable read- 

 ings to be taken 

 from the ver- 

 nier scale on 

 the movable 

 hal.f of E. 

 N reflects light 

 on the scale, while is a 

 lamp for providing light 

 rays into the polariscope. 

 P is the ordinary reflected 

 ray of light, the polarised 

 ray passing through the so- 

 lution in C. A fewer number 



Polariscope. Diagrams of a standard instrument f P^ 3 . are H . used - 

 seen in section. See text See Polarisation of Light. 



Polarity. Property of having 

 poles, i.e. ends with some opposite 

 quality or qualities. The best 

 known example is the ordinary bar 

 magnet with a N. and S. pole. The 

 line joining such poles serves as an 

 axis of reference in considering any 

 physical problems, properties, etc., 

 connected with the body. 



Polar Regions. Term used to 

 designate the areas which surround 

 the earth's geographical poles. 

 They are limited respectively by 

 the Arctic and Antarctic circles. 



At the spring equinox, in March, 

 the North Pole begins its " day," 

 which lasts for half a year until the 

 autumnal equinox in Sept. On 

 midsummer day, in June, there is 

 no sunset visible anywhere within 

 the Arctic circle. Between the 

 Arctic circle and the North Pole 

 there are periods without a single 

 sunset between 24 hours and six 

 months; the nearer the pole, the 

 longer the period. Whatever is hap - 

 pening in the N., the exact oppo- 

 site occurs at the antipodes in the 

 South Polar regions ; for when the 

 N. is tilted towards the sun, the S. 

 is tilted away to the same extent. 

 See Antarctica ; Arctic Circle. 



Polder (Dutch). Name given 

 to the low-lying areas of the 

 Netherlands which have been re- 

 claimed from the sea. They are 

 used mainly for pastoral purposes, 

 although considerable quantities 

 of bulbs and vegetables are grown. 

 See Netherlands ; Zuider Zee. 



Polderhoek. Village of Bel- 

 gium, in the prov. of W. Flanders, 

 about 1 m. S. of Polygon Wood 

 (q.v.). Strongly fortified by the 

 Germans, its famous ruined chateau 

 was an objective of the British in 

 the third battle of Ypres, when it 

 was captured and lost, and finally 

 retaken in the autumn of 1918. 

 See Ypres, Battles of. 



Pole. Long slender piece of 

 wood used for various purposes; 

 e.g. a carriage pole, a nag pole, and 

 a barber's pole. See Maypole. 



Pole. In geography, one of the 

 two terminal points of the earth's 

 axis. In astronomy, the celestial 

 poles are those points in the 

 heavens to which the earth's axis 

 is directed. The poles of the hori- 

 zon are known as the zenith and 

 the nadir points. See Magnetism, 

 Terrestrial. 



Pole. Term frequently used by 

 electrical engineers. In a magnet, 

 for example, there are two poles, 

 N. or positive and S. or negative. 

 In a generator the positive pole is 

 the terminal from which it is as- 

 sumed that the current issues into 

 the external circuit. The negative 

 pole is that into which the current 

 is assumed to flow from the external 

 circuit. See Magnetism. 



