422 Chronicles of Science. [July, 



objection on the part of the mine proprietors to an equitable system 

 of rating. 



The Committee at their last meeting carried the following 

 resolution by a majority of 7 to 4 : — 



" Provided always that after the passing of this act no occupier 

 of any mine within the jurisdiction of the Stannary Courts of 

 Devon and Cornwall, or of the High Peak Mining Customs and 

 Mineral Courts Act (14 and 15 Yic. c. 94), and the Derbyshire 

 Mining Customs and Mineral Courts Act (15 and 16 Yic. c. 163), 

 shall be liable to be rated to the relief of the poor, to the county 

 and highway, and other local rates, and no assessment shall be 

 made on such mines, otherwise than on the owner or owners in 

 respect of the rent, royalty, toll, or due reserved to him or them." 



It now remains to be seen whether the House of Commons will 

 accept the amended bill. 



The present condition of the Tin and Copper Mines of this 

 country will be best understood by the following statement of facts. 



In 1860, 405 mines paid dues upon the ores raised to the 

 Stannary Court. In 1866, they were reduced to 315. The value 

 of all the ores upon which those dues were paid was in 1861 

 2,068,123Z. ; whereas in 1866 it was only 1,404,462Z. In 1861, 

 the number of Cornish and Devonshire Mines paying dividends 

 amounted to fifty-eight ; but in 1866 there were but twenty-six 

 mines which paid dividends. With two or three exceptions the 

 dividends were small, and in some of the mines it was deemed 

 prudent to pay the dividend out of the reserved funds, as widows 

 and orphans were entirely dependent on them for their subsistence. 

 Within the last eighteen months about 11,500 persons have been 

 thrown out of employ; and of these above 7,000 have left the 

 Western counties. Six thousand have emigrated to America, to 

 Australia, and New Zealand ; the others having found employment 

 in the collieries of Scotland, and a few on the lines of railway now 

 in process of construction. 



Safety Lamps have been made the subjects of a series of most 

 carefully contrived experiments by some of the colliery engineers 

 of the Newcastle district, and the result has been to show that none 

 of the lamps at present in use, under the circumstances to which 

 they are exposed in well-ventilated collieries, are safe. The experi- 

 ments were made after the following manner. The safety lamp 

 under trial was placed in a wooden pipe, through which any 

 mixture of gases and atmospheric air could be driven at any 

 velocity, the rate being measured by Dickinson's or Biram's 

 anemometer. It was found when an explosive mixture of car- 

 buretted hydrogen and atmospheric air — fire-damp — was made to 

 travel the pipe at a velocity of 8 feet per second, the ordinary 

 Davy Lamp began to heat, and in a few moments it exploded out- 



