53 



231 



Kiuption commenced 



6h. 38'5ü"p. m. 

 40' 42" 

 42' 24" 

 44' 15" 

 45' 55" 

 48' 00" 



6h. 39' 00" p. m. 

 41' 10" 

 43' 55', 

 46' 20" 

 48' 50" 



Table II. 



The S o u t h e !■ n Geyser. 



Length of 



Eruption ended 



6h.37'48"p. m 

 39' 39" 

 41' 24" 

 43' 15" 

 45' 00" 

 46' 55" 

 48' 45" 



eruption 



49" 

 42" 

 51" 

 45" 

 60" 

 45" 



Pause 



Period 



The Northern Geyser. 



40' 35" 95" 



42' 45" 95" 



45' 38" 103" 



47' 48" 88" 



Mean : 



147.5" 



I made the two observations simultaneously, while standing near the southern 

 spring, I consequently paid more attention to it than to the northern spring. The 

 irregularities observed in the periods of the latter may therefore very easily be due 

 to inaccuracy in the observations. The possibility of inaccuracy is enhanced by 

 the fact that the beginning and ending of the eruptions of this spring are observed 

 with difficulty, as the eruption rises very gradually to its full height, and falls like- 

 wise very slowly. It was therefore difficult at a distance to decide when the erup- 

 tion should be considered as begun or ended. The following observations, made 

 on the 7th. August 1906, seem to strengthen the conclusion that the irregularity is 

 due to inaccurate observation. Barometer 754.3 mm. Temperature of the air, 16' C. 



Table III. 

 The Northern Geyser. 



Eruption commenced 



llh. 30'35" 

 34' 15" 



38' 00" 



Eruption ended 

 llh. 29' 27" a.m. 

 33' 05" 

 36' 48" 



Period 



220" 

 225" 



These measurements show that it is possible for this spring also to have 

 eruptions with very regular periods. 



