March, 1919] Temperatures of Ten Thousand Smokes 



261 



8. ''Pimples:'' At the lower (north) end of the Valley where 

 sand storms are frequent, many of the smaller vents have built 

 up conspicuous mounds around their orifices from the wind 

 blown sand, which sticks to their moist surface and becomes a 

 permanent addition to the pile. These mounds, see cut below, 

 vary from six inches to two feet in height. Their temperatures 

 did not exceed 100° C. We found them southwest of No. 24 

 and north of No. 1 in considerable numbers. 



Photograph by J. W. Shipley 



"PIMPLES" ON THE NORTH END OF THE MUD FLOW. 



Near the north end of the mud flow many stratified piles are formed by wind blown 



ash which is caught and held by the steam from small fumaroles, giving 



the appearance of pimples breaking out on its surface. 



LIST OF FUMAROLES. 



In the list of fumaroles the maximum temperature (cor- 

 rected) recorded follows the number. Next are given compass 

 bearings on triangulation stations on the mountains around the 

 Valley, whereby fumaroles may be located again with certainty. 

 No attempt has been made to correct for magnetic variation, 

 because the compass is subject to local irregularities which 

 would made correction difficult but do not affect the value of 

 the bearings for relocating the fumaroles, since the irregularities 

 will probably remain sensibly constant for a given station. 



The photograph numbers given after the descriptions are the 

 serial numbers of the photographs secured by the expeditions. 

 Complete sets of the prints are on file in the office of the National 



