PART III. 



THERMA-HYDKOLOGY. 



Contents. 



Page. 



Introduction 355 



Section I. General Features 356 



Chap, I. Definition of Thermal Spring — Source of Water — Outflow — Life in 



Hot Springs, and Distribution 856 



II. Geological Features 361 



III. Classification and Therapeutics 364 



IV. Comparison of Geyser Regions 368 



Section II. Physical and Thermal Conditions 372 



Chap. V. Forms of basins, Ornamentation, and Color of the Water 372 



VI. Temperature 380 



VII. Chemistry of Thermal Waters 387 



Section III. Formations and Deposits 398 



Chap. VIII. Physical Features of Deposits 398 



IX. Chemistry of Deposits 405 



Section IV. Geysers 416 



Chap. X. Definition of Geysers, and Theorys 416 



XI. Peculiarities of Geyser Eruptions 423 



XII. Influences Modifying Geysers 424 



INTBODJJCTION. 



For the general title of this portion of my report I have combined 

 the words thermal, hot or warm, and hydrology, the science of water, into 

 Thermahydrology, as the best general term to include the remarks made 

 in the following chapters. I am well aware that this part of my report is 

 not exhaustive, but the remarks that are made may suggest some lines 

 of investigation that can be followed in the future. The preliminary 

 work in the Park has now been done. Charts are made on which the in- 

 dividual springs are enumerated, so that what remains to be done is to 

 have careful observations made with a view of determining, if possible, 

 the laws governing the action of the various geysers. Protracted observ- 

 ations in detail carried through several successive seasons are necessary 

 to obtain even an approximate idea of these laws. It is to be hoped that 

 an opportunity for this kind of work will be afforded before long. The 

 example of New Zealand might be followed and medical officers ap- 

 pointed, as in the Rotorua district, where also hospitals and laboratories 

 have been established. 



355 



