280 Scientific Proceedings, Royal Dublin Society. 



serves to ignite each flame as it comes into line with it by the revohition of 

 the blowpipe. The parts A and B are provided with fibre discs with milled 

 edges, to enable them to be easily turned when hot. The tube on which the 

 whole is supported is held in simple trunnion bearings, and provided with a 

 quadrant, which allows of the flame being tilted to any desired position. The 

 gas and air are led in through short tubes which are placed at 180° to the 

 position taken up by the flame. The whole is mounted on a simple stand of 

 heavy metal, provided with holes for screwing to the bench. 



This design of blowpipe, based as it is on theoretical considerations, 

 naturally admits of modification and adaptation to meet particular purposes ; 

 and it will not be out of place to indicate some of the chief advantages 

 inherent in this form. 



Owing to tlie provision of a number of different air-jets for the different 

 flames, the range of this blowpipe is very great, when we consider the small 

 size of the actual working parts. The series of flames may start with a 

 small flame about the size of that produced by a fine mouth blowpipe, and 

 extend to a size which is limited only by the size of the blowpipe and the 

 diameter of the gas-pipe, and yet each flame will be perfectly formed, since 

 it is supplied with a jet of just the right size for its particular requirements. 

 This result is obtained with gas at about four inches of water, and on air- 

 pressure of about twelve inches of water. As well as this succession of 

 round flames, one or more flat blowpipe flames may be produced by suitably 

 altering the gas and air orifices. 



The change from any one flame to any other is instantaneously made by 

 mere rotation of the blowpipe on its axis, without any adjustment of taps, 

 with the assurance that a perfect flame of the size desired will be produced 

 in all cases. The character of the series of flames can be altered by the 

 relative rotation of the two discs, thus producing a series of softer or harder 

 flames according to the direction of rotation. 



A further advantage is to be found in the fact that once the ratio of gas 

 to air in any one flame is flxed (by inserting a suitable jet) the flame becomes 

 standardized, and can be exactly reproduced at any time by using the same 

 gas- and air-pressure. Consequently, if on one occasion any particular flame 

 is found suitable for any operation, either in glass-blowing or general 

 laboratory work, by noting the number of the air-jet, this flame can be 

 reproduced easily at any future time with great precision, thus leading to 

 the saving of time and the production of uniform results. 



The principle also admits of an important development from the manu- 

 facturing point of view, inasmuch as it is possible by inserting the correct 

 jets to arrange so that the blowpipe will give a series of flames adapted to 



