VACUUM CLEANER 



6019 



VALENS 



VACUUM CLEANER, vak'uum kleen'er.&u 

 apparatus for removing dust from interior walls 

 and furnishings by suction. It consists of some 

 form of suction fan or air-exhausting pump 

 which draws air through a nozzle. There are 

 several patterns on the market. In the first 

 type that was designed the air pump was oper- 

 ated by a large gasoline engine which was 

 driven on a truck from house to house; connec- 

 tion from the street was made by a long rubber 

 hose, and the dust was drawn through the hose 

 and expelled into a box in the wagon. Later, 

 stationary' engines, run by gasoline or electricity 

 and operating a pump connected with a system 

 of pipes leading to the different floors, were 

 used in large buildings. 



The most recent development is a small 

 portable machine which may be attached to the 

 socket of an electric lamp. In this form, the 

 motor and suction fan are placed just above the 

 nozzle, which slides on rollers, and the dust 

 passes into a removable bag of closely-woven 

 material, through which the air escapes, the 

 being retained. In some of the cleaners, 

 on is caused by bellows operated by hand 

 or foot power. The vacuum cleaner is part of 

 the equipment of the most modern office build- 

 apartment houses and homes, and every- 

 where is largely displacing the broom. The 

 portable electric cleaners, with several attach- 

 ments and nozzles of various shapes, range in 

 price from twenty-five to fifty dollars. 



VACUUM PAN, a device used to evaporate 

 liquids at a temperature less than the ordinary 

 boiling point, especially in the sugar-refining 

 industry. It consists of a closed vessel heated 

 by a steam jacket, which is equipped with an 

 air pump so arranged that the steam and air 

 may be constantly removed from the surface 

 >o liquid. This reduces the pressure on the 

 ce and permits boiling and evaporation of 

 tin- liquid without danger of its burning. The 

 operation of a vacuum pan is based on the prin- 

 ciple that the boiling point of a liquid is low- 

 ered as the pressure upon its surface decreases. 

 See BOILJNO POINT; SUGAR. 



VALDAI, valdi', HILLS, a low range in 

 West-Central Russia about midway betv 



j of Pctrograd and Moscow, which 



forms a watershed between the Volga and the 



per, and the rivers flowing toward the 



Baltic Sea. These hills extend for about 250 



-. and gradually rise from the surrounding 



plain to a it j ion of 1,150 feet 



Formerly the Vuldais \ 



lopes have been cleared, and 



on them hemp, flax and cereals are successfully 

 grown. Copper, iron, magnetite, lead and salt 

 are found in the range. 



VALENCIA, valcn'thia, a city of Spain, 

 capital of the province of the same name, and 

 in population the third city in the kingdom, 

 ranking next to Madrid and Barcelona. It lies 

 on the River Guadalaviar, three miles from the 

 Mediterranean coast and 185 miles southeast of 

 Madrid. The city occupies an attractive site 

 in the midst of a fertile plain. Its ancient 

 walls, originally built by the Romans, were 

 torn down in 1871, and have been replaced by 

 handsome boulevards; two gateways with their 

 picturesque towers are all that remain of the 

 old fortifications. 



Within the city one sees a mixture of Ori- 

 ental civilization and that of the present age. 

 There are rows of white dwelling houses in the 

 Moorish style of architecture, and innumerable 

 domes and towers roofed with gold, blue and 

 white tiles; many of the crooked, narrow streets 

 have been replaced by broad avenues, and the 

 city has such modern improvements as el 

 tramways, gas and electric plants and good 

 drainage and water-supply systems. The city's 

 many interesting structures include a cathedral, 

 dating from the thirteenth century; a Gothic 

 bell tower 152 feet high; the episcopal palace, 

 with a valuable library; the silk exchange, a 

 handsome building in Gothic- i the pro- 



vincial museum, which contains a valuable col- 

 lection of paintings. Yalmc . 

 which is now one of the foremost in Spain, and 

 the municipal botanical pardons, outside the 

 line of the old walls, are unsurpassed anywhere 

 else in the country. 



The city is an important in! r, and 



is connected by two lines of railway and two 

 tramways with its port on the Mediterraii 

 The latter has a .-pariou.x and up-to-date har- 

 bor. The leading manufacturing 

 Valencia is the silk industry, but th- place is 

 noted also for the production of colored tiles. 

 It carries on a thriving export trade in oranges 

 and other fruits. Population in 1910. 233348. 



VALENS, m'linz (about 329-378), a Roman 

 emperor of the East, brother of Vulentinian I, 

 who made him his colleague in 364 and gave 

 him as his territory Thrace, Asia and E- 

 At the outset of his n al, Procopius, 



had himself proclaimed emperor, and not until 

 380 was the usurper finally put down. V: 

 won general popularity in that same 

 reducing all taxes felt th 



need of the funds of which he thereby deprived 



