PROCEEDINGS OF THE COTTESWOLD CLUB 28 1 



Experiment. — I have here a small glass model in which the above 

 conditions are realized very simply. The glass flask, A, which 

 represents the subterranean reservoir, is fitted with a cork through 

 which two tubes pass; — one, B, corresponding to the course of the 

 springs which feed the geysirs, reaches from the bottom of the flask 

 to a bottle of water, C, placed on a high .stand ; — the other, D, larger 

 in diameter, passes vertically upwards through the bottom of a basin. 

 This latter tube represents the main outlet or shaft through which the 

 discharge of the geysir takes jilace. A gas-burner, placed under the 

 flask A, raises the temperature of the water, like the volcanic strata 

 which underlie the whole of the geysir region. 



Water is allowed to flow slowly from the reservoir C until the 

 flask and the discharge pipe are filled. Heat is then applied until the 

 contents of the flask reach the boiling point corresponding to the 

 pressure of the column of water in the tube added to the pressure of 

 the external air. Then a little further supply of heat causes a sudden 

 formation of steam which drives out all the contents of the tube and 

 some of the water in the flask, in the form of a fountain. The action 

 then subsides until the flask and tube are again filled with water from 

 the bottle, and when this has become sufficiently hot, another out- 

 burst takes place. 



I have thus given a brief sketch of a small portion of 

 what I saw myself during the necessarily limited time 

 which I spent in the heart of the Rocky Mountains, 

 and I will, in conclusion, strongly urge everyone of those 

 who hear me to pack up his portmanteau this very night 

 and start by the first train to-morrow morning, with or 

 without the leave of the higher domestic powers, to 

 explore for himself the natural marvels of that most 

 wonderful region, — the Yellowstone National Park. 



