The Maps of tJic Glacier. 55 



at 200-foot intervals ; it must be remembered that these pretend 

 to no accuracy, but merely serve to show the general form of the 

 surface, as well as I can indicate it by aid of memory and pho- 

 tographs. The altitudes above mean tide which were deter- 

 mined trigonometrically are given in black figures ; those deter- 

 mined by barometer or estimated, in blue figures. Camp Muir 

 was estimated to be 25 feet above mean tide. 



For the inlet I have made a separate map on a scale 3-oioD 

 which shows well the position of the flags we used for measuring 

 the motion of the glacier and the form and position of the ice- 

 front at various times. The contour lines here also are only very 

 roughly approximate ; the interval between them is 100 feet. 

 The numbers give altitudes determined trigonometrically, ex- 

 cept those on the contour lines, which are estimated. 



