134 



POT 



Posen 



II 

 Potatoes. 



POSEN, or POSNA, the capital of Russian Poland, is 

 situated at the confluence of the Wartha and the Proz- 

 na. The town is upon the whole regular, and is en- 

 circled with a mound and ditch. The principal public 

 buildings are the cathedral, the council-house, the 

 principal guardhouse, the cidevant Jesuits college, a 

 theatre, a gymnasium, a college for rearing teachers, 

 and a school for midwifery, several churches and con- 

 vents, and the episcopal palace, which is a fine struc- 

 ture. The castle stands on an island in the Wartha. 

 The principal manufactures are linen goods, leather, 

 watches and fire-arms ; and corn, wool, arid timber, 

 are the chief articles of export. Population about 

 20,000. East Long. 16 33' 56", and North Lat. 52 

 24' 39". 



POSITION, is the name of a rule in arithmetic, 

 by means of which an unknown number is determin- 

 ed by means of one or more suppositions or assumed 

 values of it. Position is divided into single and double. 



In single position, the false conclusion is to the false 

 position as the number given is to the number sought. 

 Thus, ^ 



Ex. A manufacturer being asked how many work- 

 men he had, replied, that if he tripled the number he 

 had, and added one-eighth of his number to that, he 

 would have 150. 



Let us suppose 32 to be the number, then 32 X 3 + 

 4=100 instead of 150. Consequently 100 the false 

 conclusion, is to 32 the false supposition, as 150 is to 

 48, the true number of workmen. 



In double position the answer is obtained by trvo 

 suppositions. The rule, therefore, is to assume two 

 different numbers, and subject them to the conditions 

 given in the question. Then the difference of the re- 

 sults thus obtained, is to the difference of the assumed 

 numbers as the difference between the two results, 

 and either of the others is to the correction to be ap- 

 plied to the assumed number, from which the result 

 was obtained. This rule was given by Mr. Bonny- 

 castle in his arithmetic, published in 1810. 



The following .more general rule has been given 

 by Mr. Thomson of Belfast, in his very useful treatise 

 on the theory and practice of Arithmetic. 



" Having assumed two different numbers, perform 

 on them separately the operations indicated in the 

 question, and find the errors of the results. Then as 

 the difference of the errors, if both results be too 

 great or both too little, or as the sum of the errors if 

 one result be too great and the other too small, is to 

 the difference of the assumed numbers, so is either error 

 to the correction to be applied to the number that pro- 

 duced that error." 



As all the questions that are capable of being solved 

 by these rules, can be done with more facility by the 

 .simplest rules of algebra, it is needless to occupy any 

 more space with their illustration. The principle on 

 which they rest is quite correct, for all questions 

 which carr be resolved by a simple equation, but in 

 relation to other equations, the rules give only ap- 

 proximate results. See ALGEBRA, Vol. I. Sect. IV. 

 p. 429. 



POST OFFICE. See ENGLAND, Vol. IX. p. 21. 



POTASH. See ALKALIS, Vol. I. p. 526; CHEMIS- 

 TRY, Vol. VI. p 44, 45 ; and MATERIA MEDICA, Vol. 

 XIII. p. 352. 



POTASSANE. See CHEMISTRY, Vol. VI. p. 65. 



POTASSIUM. See CHEMISTRY, Vol. VI. p. 44. 



POTATOES. See AGRICULTURE, Vol. I. p. 304 

 307 ; and HORTICULTURE, Vol. XI. p. 253256. 



POTOSI. See BUENOS AYRES, Vol. V. p. 52, 53, Potosi 

 &c. and the books quoted under that article. li 



POTSDAM, a city of Prussia, in the Middle Mark 1>otter y- 

 of Brandenburg, and the capital of a province of the ^^^V*** 1 

 same name. It is situated on the north bank of the 

 Havel, which forms, as it were, a series of lakes round 

 the town. The city, which lias the general form of a 

 square, is divided into the Old and New Town. The 

 Old Town contains only four streets. The New Town 

 was chiefly built by Frederick II. The streets of it, 

 though regular and spacious, are not well paved ; and 

 several of them have such magnificent fronts as to re- 

 semble rows of palaces, though the houses are inferior 

 within, and are inhabited by ordinary persons. A 

 ditch and wall encircle the town and there are four 

 gates towards the land, and four towards the Havel. 

 The palace, which is the chief public building, stands 

 on the margin of the river. It is a noble building, and 

 was begun in 1660. A colonnade, a cupola, and a 

 marble staircase, are among its principal ornaments. 

 Its extensive gardens stretch along the river ; and on 

 the front of it is a square for exercising the troops of 

 the garrison. It has also a theatre, a menagerie, and 

 spacious stables. The town-house, on the plan of that 

 of Amsterdam, was built in 1754. The town-church, 

 situated not far from the castle, is a fine building. Be- 

 sides other five churches and a synagogue, there is the 

 garrison church, which is large, and contains statues 

 of Mars and Bellona. Under the pulpit, which is 

 constructed of marble, is the monument of Frederick 

 William. In the market-place, which is ornamented 

 with the statues of the kings of Prussia, is a pyramidal 

 obelisk of four sides, seventy-five feet high, and made 

 of variegated Silesian marble. On one side is a marble 

 bust of the king ; and at each corner of the pedestal, 

 which is of white Italian marble, is a statue of the same 

 marble. The places of public instruction are, a lyceum, 

 two public schools, and the garrison school. There is 

 here an infirmary, a poors-house, and an orphan-house. 

 This last building, founded in 1724, maintains and 

 educates 2000 soldiers' children of both sexes, and has 

 one Lutheran and one Calvinist preacher attached to 

 it. The principal manufactures of Potsdam are those of 

 cotton-lace, silk, velvet, linen, woollen, wax- cloth, lea- 

 ther, hats, and fire-arms for government. Brewing is 

 carried on to a great extent. The palace of Sans-Souci 

 is about three-fourths of a mile distant from Potsdam. 

 It is only one story high, with a round pavilion at 

 each end ; in one of which is the library, as it was left 

 by Frederick II. at his death. There are two adjoin- 

 ing buildings,, one for paintings, and the other for 

 court entertainments. 



The population of Potsdam is about 15,000, besides 

 about 7000 soldiers. Distance from Berlin 15 miles, 

 S. W. East Long. 12 5' I", North Lat. 52 24' 43". 



POTTERY, called also earthen-ware, is a term Definition, 

 used to denote vessels of any shape or size formed of 

 earth or clay ; or the art of manufacturing them. Pot- 

 tery may be regarded as merely the coarser species of 

 porcelain. The articles of the former manufacture, while 

 they require fewer materials, and these less pure, though 

 more fusible, require also much less skill and delicacy 

 in the making ; are incomparably cheaper, particularly 

 the coarser kind ; are ruder and more inelegant ; and 

 are, from the grossness of the materials of which they 

 are formed, unsusceptible of the high ornament and 

 polish, characteristic of porcelain. 



These articles, however, though devoid of the beau- Origin. 

 ty and delicacy of porcelain, must have been invent- 



