218 EEPORT UNITED STATES GEOLOGICAL SURVEY. 



These facts are recorded in tlie liope that ultimately, when more data 

 are accumulated, they may help to solve some of the problems presented 

 by the geysers. 



I think that the balance of proof is against the idea that there is any 

 connection between the Turban, the Grand, and the Steam Vent (incor- 

 rectly called the Saw-Mill by Comstock). The Turban acts frequently, 

 and it is merely a coincidence when it acts in concert with the Grand. 

 Professor Bradley in 187!i thought that the Turban was startled into 

 more violent action by the eruption of the Grand, and saw it rise and 

 fall synchronously with it. The same year, however, as I have noted, 

 it was quiet during some of the most active periods of the Grand and 

 spouting' during others. As to the Steam Vent, I saw it in action just 

 before the eruption of the Grand, during which it was iDerfectly quiet, 

 whereas Professor Comstock saw it spouting simultaneously and ceas- 

 ing with the Turban and Grand. 



No. 21. 8aw-Mill Geyser. — This name was given in 1871 by Mr. Schon- 

 born, our topographer, to a very active little geyser on the same mound 

 or terrace with the Grand, from which it is distant 450 feet to the south- 

 ward, being separated only by a few trees. It is a very interesting gey- 

 ser, although one of the smallest in the Basin. The mass of water thrown 

 uj) is not great in quantity, but it is so broken into spray and glittering 

 crystal drops tbat it presents a beautiful appearance, especially in the 

 bright sunlight, when a rainbow may be seen in its fountain-like column. 

 Preceding the eruption the basin fills with water. The following is the 

 description of the eruption I witnessed in 1872 ; 



There were noticed during the eruption five distinct periods of action 

 per minute, each one made up of fifteen impulses. While this is going 

 on the mass of water pulsates and reaches a height of about 5 feet, and 

 through this jets shoot to 15 or 20 feet. The following are the notes 

 made^in 1878: 



August 27. — Saw-Mill is in action at 6.25.15 p. m. 



August 28. — Saw-Mill is spouting at 12.21.41 p. m. 3.19 p. m., spouts 

 for 3 hours. 



August 29. — 8.32.52 a. m., spouts for about 3 hours. 4.36 p. m., spouts, 

 but duration not ascertained. 



August 30. — 1.20 p. m., in action. 5.20 p. m., in action. 



August 31. — 10.15 a. m., in action. 



September 8. — 7 p. m., Saw-Mill is spouting. 



iSeptemher 9. — 11 a. m., in action. 6.38 p. m., began to spout. 



September 10. — 9.50 a. m., the inner basin is filled with water. 10.30 

 a. m., outer basin is filling. 11.46 a. m., the spouting begins with 

 thumpings and lively spurts, 20 to 25 feet. The duration of the erup- 

 tion is 1 hour and 49 minutes. After the eruption steam escapes, and 

 in half an hour the basin is empty. 2.45 p. m., the basin is filling. 

 3.17.45 p. m., the Saw-Mill begins action with a whirling motion to the 

 mass of water and occasional high spurts. The eruption lasts 2 hours, 

 12 minutes and 15 seconds. 



The interval between these eruptions was 3 hours 31 minutes and 

 45 seconds; the interval of quiet being 1 hour 47 minutes and 45 sec- 

 onds. There are probably about five or six eruptions in 24 hours, 

 although more observations are necessary- to determine positively the 

 exact interval. The Saw-Mill Geyser described by Professor Comstock 

 in his report (p. 254) is not the one we named in 1871, but the steam 

 vent near the Grand. I have taken the name he gives its companion 

 for the companion of the Saw -Mill, viz, No. 22, and called it Tardy 

 Geyser. 



