I 



On the Assamese Method of Blasting Rocks. Ill 



* 

 gases. That eminent chemist had one of them made for his own 

 use, and another was executed for Dr Fyfe ; but as no account 

 of it has yet been published, you would oblige me by insert- 

 ing the following brief description of it in The Edinburgh Jour^ 

 nal of Science. The advantages of this apparatus are, that it 

 does away with bent tubes and luted joints of Woolfs, all of 

 which can be ground with ease. The liquid to be impregnated 

 is advantageously exposed to the gas. As there are no lutings, 

 it can be put up and in action in a few minutes, and as quick- 

 ly dismounted ; and not at all liable to derangement. In Fig. 2. 

 Plate III. A is the retort; B the receiver for the condensable 

 part of the product ; C contains the liquid to be impregnated, 

 which is filled up to the dotted line D ; E is a vessel open at 

 the bottom, into which the liquid ascends during the action of 

 the apparatus ; F is to keep up pressure on E, when the stopper 

 is out ; G is a conical stopper to increase the pressure on the 

 whole. A stop cock at H would be very convenient, to ex- 

 amine a little of the liquid as the operation goes on. This 

 can be introduced at G ; and if the safety tube described in the 

 last number of this work were applied at the top, in place of 

 the conical stopper at G, it would render it more complete. 



Art. XIX. — Account of the Assamese Method of Blasting 

 Jiocks. Communicated by a Correspondent in India. 



An Assamese stone-cutter has shown me a mode of blasting 

 rocks, which I think superior to any thing practised in Eng- 

 land, and you may perhaps consider it worth communicating 

 to The Edinburgh Journal of Science. The old mode of ram- 

 ming has you know been superseded of late by the use of loose 

 sand poured over the powder ; but whatever may be the case 

 with the softer description of rocks, I have always failed in this 

 way here, except in one instance, probably owing to the ex- 

 cessive strength and hardness of the granite and primitive 

 greenstone, on which the experiment has been tried at least a 

 dozen of times, and in holes nearly a foot deeper than is stated 

 to be necessary in the Supplement to the Encyclopcedia and 

 Philosophical Magazine, where the method with sand is de- 

 scribed. The following is the result of the Assamese plan. 



