260 The Ohio Journal of Science [Vol. XIX, No. 5, 



perature, but in one of them (No. 21), we found a temperature 

 of 196 C. in a lateral fissure just inside the rim. 



5. Cracked areas: Areas with a hard baked surface, much 

 cracked and honey-combed with small fissures. Definite indi- 

 vidual vents are rare. The surface cracks are filled with steam 

 coming from below, under considerable pressure. The gases 

 in the steam form a thick deposit on the surface of the mud. 

 They are abundant on the slopes east of Falling Mountain. The 

 emanations from these areas are so copious and they, appear 

 so hot and so charged with noxious gases that no one has yet 

 had the temerity to undertake their exploration. 



6. Mud blanketed areas: Although the general surface of 

 the original mud flow that forms the floor of the Valley has 

 become hard and firm, there are many areas covered with soft, 

 sticky blue mud, which is kept hot by the steam which issues 

 through it in considerable quantity. The activity of these mud 

 blanketed areas takes on one of two forms. Usually it gives 

 rise to myriads of small steam jets best described as mud hissers, 

 which come out from indefinite cracks. Although the mud is 

 always blue, the surface is generally covered with a chestnut 

 brown crust which will sometimes support a man's weight. 

 The minute orifices, by which the steam punctures the crust, 

 probably do not constitute permanent vents but presumably 

 shift about rather rapidly. The temperature of the steam and 

 of the surrounding mud was close to that of boiling water. 

 The conspicuousness of these areas varied greatly with the 

 humidity of the air. Although these areas are very common in 

 the center of the Valley, we located only one of them with 

 compass bearings. This one was No. 38, which is the most 

 northerly of these areas in the Valley. 



7. Mud volcanoes: In some of the mud covered areas the 

 activity produces a more or less violent ebullition, forming 

 mud pots and mud volcanoes. The consistency of the boiling 

 mud varies from a soupy liquid to a viscous mush. The 

 temperature of all was 100 C. We found only two areas of 

 mud volcanoes in the Valley. The first, (No. 48), is in the 

 center of the Valley and is made up of some 15 or 16 crater- 

 like pots. The other area, (No. 44), is located near the 

 northern end of the Valley and containes a line of six very 

 active boiling pots of mud. 



