560 Chronicles of Science. [Oct., 



aiSuent, to Coconada. A branch line for the cotton alone was long 

 ago projected to Hingunghat. Now there is the coal. If even 

 half of Mr. Fiyar's expectations are realized, the least known part 

 of India will be opened up, and the feudatory provinces of the 

 Nizam, who will be a minor for the next fom-teen years, will be 

 enriched, while they are made to contribute their wealth of cotton 

 and coal to the general good." 



Mr. Mark Fryar has recently published a letter "On Coal- 

 Mining in India," addressed to the " proprietors and managers of 

 coal-mines in India," which cannot but produce a beneficial result 

 in directing attention to improved methods of working the coal- 

 mines. 



In connection with this subject of coal-mining, Mr. Henry 

 Bessemer, who is well known for his process of manufacturing 

 steel, has — in devising a process for the production of a most intense 

 heat for metallurgical processes — been led to suggest a modified 

 form of that arrangement for lighting mines.* By combustion 

 under pressure, Mr. Bessemer obtains the most intense heat, and 

 the most vivid light, " a hght that never fails, that never goes out, 

 that never requires trimming, and, above all, a light that effectually 

 prevents the mixture of air and gas which pervades all coal-mines 

 from entering the flame and becoming ignited. Now these are pre- 

 cisely the conditions obtained by combustion under pressm'e, which 

 offers to the miner a source of the most brilliant light wholly inac- 

 cessible to the inflammable air of the mine. As a simple illustration 

 of the fact, let us suppose a small iron box, a httle larger than a 

 policeman's lantern, having a thick plate glass or a bull's-eye ono ne 

 side of it ; in the lower part is a common gas-burner, supphed by a 

 pipe from a gasometer above ground ; the supply of air to support 

 combustion is arranged in a similar manner, and supphed under 

 pressure from above ground ; a small aperture is made in the top of 

 the lantern for the escape of the products of combustion. Now, if 

 air and gas are supplied to this light under a pressure of, say 1 lb. 

 per square inch, the light would be brilliant, and the escape from 

 the orifice at this pressure (or even far less) would prevent the possi- 

 bility of any external gases entering and becoming ignited. In this 

 way every gallery in a mine may be hghted like a workshop, to 

 the great comfort and cheerfulness of those whose whole lives are 

 spent in the cheerless gloom of these dangerous workings." 



The mode of advancing the hght as the work progresses, and 

 its direction by the use of reflectors, and other necessary details of 

 the system, are simple enough, and need not be here entered into. 



In Cornish mining a most decided improvement is evident, con- 

 sequent upon the increased and remunerative price of tin. The 



* See MctiilUiifrioal ChvonicU-s. 



