VII.] 



THE BOUQUET' OF WATERWORKS. 



79 



pipe driven up in confusion before the steam at the moment 

 it obtains its liberation. 1 



The accompanying sketch may perhaps help you to under- 

 stand my meaning. 



The last gulp of water had disappeared down the funnel. 

 We were standing at the bottom of the now empty basin, 

 gazing into each other's faces with joyous astonishment, 

 when suddenly we perceived a horseman come frantically 

 galloping round the base of the neighbouring hill towards us. 

 The state of the case was only too evident. He had seen 



1 Professor Bunsen has lately announced a chemical theory, which I 

 believe has been received with favour by the scientific world. He points 

 to the fact that water, after being long subjected to heat, loses much of 

 the air contained in it, has the cohesion of its molecules much increased, 

 and requires a higher temperature to bring it to boil ; at which moment 

 the production of vapour becomes so great, and so instantaneous, as to 

 cause explosion. The bursting of furnace boilers is often attributable 

 to this cause. Now, the water at the bottom of the well of the Great 

 Geysir is found to be of constantly increasing temperature up to the 

 moment of an eruption, when on one occasion it was as high as 26 1° 

 Fahrenheit. Professor Bunsen's idea is, that on reaching some unknown 

 point above that temperature, ebullition takes place, vapour is suddenly 

 generated in enormous quantity, and an eruption of the superior column 

 of water is the consequence. 



