PEALE.] 



UPPPER GEYSER BASIN OLD FAITHFUL. 



223 



given ia the table [see table followinoj], tbe first spurt occurred only 3 minutes before 

 the ejection began, and the preliminary agitation in the fourth eruption took place 

 but 2 minutes previously. 



Dr. Heizmann found the temperature of the water at the base of the 

 mound in pools to be 70° between the eruptions, while those about the 

 vents (containing pebbles) had, just previous to an eruption, tempera- 

 tures of 1220, 136°, and 138°.* 



The following table is from Professor Comstock's report,t and to it I 

 have added a column showing the intervals between the beginnings of 

 the eruptions as in the table from my report for 1872, already given : 



Table of Comstoch's observations. 



u 

 .2 



ti 



<s 

 o 

 d 



Date. 



Eruption began. 



Eruption ceased. 



Dnration. 



Intervals b e- 

 tween begin- 

 nings of erup- 

 tions. 



Intervals of 

 quiet. 



1 



1873. 

 Aug. 25 

 Auir. 25 

 Aug. 25 

 Ausr. 25 

 Aug. 25 

 Aug. 25 

 Aug. 25 

 Aug. 25 

 Aug. 25 

 Aug. 25 

 Ancr. 25 



h. m. 8. 



10 38 00 a. m. 



11 36 00 a. m. 



12 39 00 p. m. 



1 41 15 p.m. 



2 45 20 p. m. 



3 .53 35 p. m. 

 5 11 10 p.m. 

 C 03 15 p. m. 



7 12 00 p. m. 



8 14 00 p. m. 



9 17 00 11. m. 



h. m. s. 



10 43 00 a. m. 



11 41 30 a. ra. 



12 44 00 p. m. 



1 45 45 p. m. 



2 50 00 p. m. 



3 58 00 p.m. 



5 15 40 p.m. 



6 07 45 p. m. 



m.s. 



5 00 

 5 30 

 5 00 

 4 30 

 4 40 

 4 25 

 4 30 

 4 30 



h. m. s. 



h. m. 8. 



2 

 3 

 4 

 • 5 

 6 

 7 

 8 

 q 



58 00 



1 03 00 

 1 02 15 

 1 03 05 

 1 08 15 

 1 17 35 



52 05 



1 08 45 

 1 02 00 

 1 03 00 



53*00 

 57 30 

 57 15 



59 35 



1 03 35 

 1 13 lot 



47 35+ 



1 04 15 



10 







11 











Is 







4 45| 



1 03 48 



59 29§ 











*In the original this is 58 minutes. I have recalculated the intervals from Comstock's data. 



tin the original this is hour 47 lainutes 25 seconds. 



tin original this is 47.25. 



§ These averages, of course, are different from the original. 



1874. — The Earl of Dunraven gives the heights to which the column 

 is projected as from 100 to 150 feet for the space of about 5 minutes. 

 While in action small j^ts and sjjurts of water were driven out from 

 numerous points in the crack or fissure which traverses the mound. | 

 The eruption described by him is like those already described. 



1875. — In the report of E. S. Dana and G. B. Grinnell, Old Faithful 

 is mentioned as follows : 



Old Faithful, the guardian of the valley, showed a very high degree of regularity 

 duriug the whole period of our stay.§ The interval between the commencement of 

 the discharges was C5 or 66 minutes, and, as timed by us for nearly twenty-four suc- 

 cessive eruptions, varied very slightly from this interval. The eruptions were of a 

 very uniform character, differing but slightly in manner or duration (about 3 minutes) 

 or in the amount of water thrown out. During the night we were roused each hour 

 by the first rush of the water and steam, and certainly nothing could be more beauti- 

 ful than this grand fountain in action, illuminated by the light of the full moon. The 

 average height of the column of water, as determined by Mr. Wood, was 115 feet.|| 



Captain Ludlow, in his report, gives the intervals as 65 minutes, and 

 gives the height as over 100 feet.^ 



'EecoDuaissance of N. W. Wyoming, p. .303. 



t/6W.,p. 249. 



t Great Divide, p. 271. 



^ About GO hours was the length of their stay. 



II Reconnaissance from Carroll, Mont., to Yellowstone National Park in 1875, p. 131. 



H/ftirf., pp. 26, 37. 



