292 



BAROMETER 



Statement of Quantities of Barley produced in Foreign Countries in the following 



years : 



BARLEY, SCOTCH, HUI.LED, POT, and PEARXi. When barley is 

 deprived of its husk by a mill, it forms the Scotch, Hulled, or Pot Barley. When all 

 the integuments of the grains are removed, and the seeds'are rounded and polished, 

 they constitute Pearl-Barley. The flour obtained by 'grinding pearl-barley to powder 

 is called Patent Barley. 



BARZiEY-SUGAR. Sugar boiled, formerly in' barley-water, until it is quite 

 transparent and crisp. It is flavoured with either orange or lemon peel. 



BARM. (Derived from the Saxon beorme ; or from beer-rahm, beer-cream.) The 

 .yeasty top of fermenting beer. It is used as leaven in bread, and to establish fer- 

 mentation in liquors. See BEER, FERMENTATION. 



BAR-MASTER. In Derbyshire, the authority to whom all disputes in lead- 

 mining are referred. He has charge of the standard ' dish ' or measure used for 

 measuring the ore. It is the same as Bargh-master. 



BARMOTE or BARGMOTXS. A court held for determining such questions as 

 may arise in lead-mining. It is usually held in Derbyshire twice a year. 



BAR OF GROUND. A course of rock dissimilar to the ordinary vein-stone 

 which runs across a mineral lode. 



BAROMETER. This name signifies a measurer of weight the column of mer- 

 cury in the tube of the barometer being exactly balanced against the weight of a 

 column -of air of the same diameter, reaching from the surface of the earth to the 

 extreme limits of the atmosphere. The length of this column of mercury is never 

 more than thirty-one inches ; below that point it may vary, according to conditions, 

 through several inches. There have been many useful applications of the baro- 

 meter, but the only one with which this Dictionary has to deal appears to bo the 

 use of the instrument in coal mines. It is now necessary, under the Coal Mines' 

 Regulation Act, that a barometer and a thermometer should be found in every colliery. 

 This has arisen from a prevailing idea that the explosions of ro-damp have, in 

 numerous instances, arisen from the alteration of atmospheric pressure. 



The relation between the state of the barometer and the occurrence of colliery ex- 

 plosions has been investigated by Messrs. E. H. Scott, F. B. S., and W. Galloway, in 

 a paper ' On the Connection between Explosions in Collieries and Weather.' Pro- 

 ceedings of the Royal Society, April 18th, 1872. 



Mr. T. Dobson read a paper ' On the relation between Explosions in Collieries and 

 Eevolving Storms ' at the meeting of the British Association at Glasgow in 1855, 

 which is printed in the Eeports for that year. Mr. Bunning has given in the 

 ' Transactions of the North of England Institute of Mining Engineers ' diagrams 

 showing the meteorological records from the observatories of Kew and Glasgow, and 

 the explosions in collieries reported in those years. It is not possible in this place to 

 examine a question complicated as this one is by the numerous conditions which 

 surround the operations of working coals, and ventilating a colliery. The results of 

 the examinations made from time to time before Committees of the House of 

 Commons, and other Committees, and by individuals, many of which are carefully 

 recorded in the paper already referred to, go to show that meteorological changes are 

 the proximate causes of a large majority of colliery explosions," and hence, therefore, 

 the necessity of carefully watching the changes of the barometer, and of regulating 



