554 Chronicles of Science. [Oct., 



been exceedingly short lived. The influence of the Continental 

 war has led to a reduction of from 127. to 15/. a ton in the price of 

 tin ore, and consequently the tin miner is dispirited, and tin mines 

 are not at all in favour with speculators. 



The following were the purchases of tin ore in each month of 

 1869 :— 



Tons. 



January .. .. 1,203 



February .. .. 1,291 



March .. .. 976 



April 1,613 



May 1,223 



June 1,277 



July . . 



August 



September 



October 



November 



December 



Tons. 

 1,138 

 1,291 

 1,144 

 1,178 

 1,279 

 1,112 



Total for 1869 14,725 



Some interesting mining operations are now being prosecuted at 

 a colliery belonging to the Earl of Dudley. We copy the follow- 

 ing particulars from the ' Birmingham Gazette : ' — This section of 

 the Dudley estate has probably been the most prolific in the world 

 so far as the actual yield of coal is concerned. It has been in work 

 for more than a hundred years, and yet its resources hold out satis- 

 factory promises of reward to the persevering efforts of those en- 

 gaged in the present experiment. In some parts of the district on 

 the east side of Dudley, coal is not to be found until the mine 

 reaches a depth of 250 yards ; in other parts, as in the celebrated 

 twelve-yard-thick measure at Fox-yards, near Sedgeley, the coal 

 crops out at the surface, and may be carted away for almost the cost 

 of loading. In most cases the coal lies in a pretty nearly level con- 

 dition, and may be worked in the ordinary way, viz. by a pit -shaft 

 sunk perpendicularly into the earth, from the bottom of which 

 " gate roads " are driven ; but in some instances the coal lies in such 

 an oblique position that to " win " it in that manner involves great 

 cost and danger. To overcome the difficulties of getting the coal 

 where it lies in this oblique position, the experiment under notice 

 has been resorted to. It consists of two tunnels driven from the 

 surface of the earth into the mine, at an angle of about thirty 

 degrees ; these tunnels are lined with substantial brickwork, and the 

 " skips " and their contents are drawn up the inclined railway, which 

 is laid down for the purpose, by an ordinary stationary engine fixed 

 on the surface. The coal already got in this way is only a few 

 yards from the surface, and it is found to be of a good serviceable 

 quality. Similar experiments were made near Bilston twelve 

 months ago, and the works are now in successful operation there. 



The discovery of a coal of good quality in Japan is of moment. 

 This Japanese coal has been discovered in the Takasima Colliery at 

 Nagasaki. According to the analysis of Dr. Jas. Martin, the con- 

 stituents of this coal are in the following proportions : — Carbon, 



