806 GEOLOGICAL SURVEY OF THE TERRITORIES. 



Boute from Gallatin City to the Geyser Basins, &g. — Continued. 



3vm 



es. 



Eleva- 

 tion. 



Grade irregular to 



Grade perfectly uniforin to — 



Camp 17, at head of Middle Caiiou 



Grade perfectly miii'orm U) — 



Camp IG, ou ]\Iadisou 



Grade nearly iinifonu to — 



Foot of Upper Canon 



Grade peifectly nuii'orm tp — 



Camp 15, at mouth of Gibbon's Fork 



Very irregular grade to — 



Head of Upper Canon 



Grade perfectly uniform to — 



Camp 14, in Lower Geyser Basin 



Grade perfectly uniform to — 



Camp 13, on East Fork of Fire-Hole River 



Divide between Madison and Yellowstone 



Grade irregular to 



Grade irregular to — 



Camp 12, at Mud Geysers, on Yellowstone River 



109.4 



119. f) 



132. 4 



136. 4 



14.5. 1 

 140. 



148.7 



1.52. 8 



1.57. 7 

 161.0 



103. 1 

 165. 8 



166. 2 

 170. 

 170. 6 

 171.0 

 172. 



175. 3 



6, 520 

 6,568 

 6,605 

 6,790 



6, 811 



7,200 



7,240 



7, 252 



7,207 

 7,400 

 8, 240 

 8,240 

 7, 950 

 7,910 

 7,740 

 7,9S0 

 7,700 



7,712 



The ordinary meteorological observations were made hourly in camp. 

 They will be found printed in full in the bulletin of meteorological obser- 

 vations. I will make a short resume of them. They were made at 

 various altitudes above the sea-level, from 4,000 to 8,000 feet. 



At Fort Ellis, elevation 4,935 feet, the meau temperature during the 

 first three weeks of July was GT^.G!, maximum, 99°.7; minimum, 33°.0; 

 lowest relative humidity .21. 



Ou the 1st of July, there occurred a heavy snowstorm, in which about 

 four inches of snow fell, which melted on the following day. 



On the 17th, there was a smart shower of hail. The minimum temper- 

 ature, at night, at an altitude above 5,000 feet, was rarely above 32°. 

 The lowest temperature experienced duriug the trip was in the camp at 

 the mouth of Gibbon's Fork, elevation 6,811 feet, 12°, in the latter 

 part of August. At the head of the- West Gallatin River, elevation 

 6,149 feet, the minimum thermometer indicated 14°., 17°., 17°., ou 

 three several nights in the latter part of September. Maximum temper- 

 atures, during the day, ranged from 65° to 93°, indicating a great range 

 of temperature during the day. 



The range of relative humidity is also very great, reaching, near the 

 middle of the day, as low as .30, and on several occasions even lower. 

 Tiie lowest relative humidity recorded duriug the trip was .22. Most of 

 the rain which we experienced during the season was in the form of 

 showers, which were of tolerably frequent occurrence, butvery few long, 

 storms occurring during the season. 



A storm of rain and hail of two days' duration was experienced at 

 Yellowstone Falls, near the eud of July. A heavy snow storm, in which 

 four inches of snow fell, occurred at the head of the West Gallatin, near 

 the eud of September. 



