380 The American Geologist. June. 1893 
such minuteness that there is no mistaking to which of them he 
gave the name Cerro de Tucumcari, and that the description he 
gives cannot be applied to the Big Tucumcari of Marcou and can 
only be applied to the one designated b}' me as Big Tucumcari, 
for the following reasons : 
First. From the distance at which Tucumcari can be seen 
from the eastward along the route traveled bj' Lieut. Simpson, be- 
ing the same route traveled by Marcou. Lieut. Simpson says of 
it: "a mile or two after crossing Emigrant creek. " I traveled 
along the same road and saw it from the top of the plains eight 
miles east of the Texas state line. 
The adjoining plate is an exact copy of Prof. Marcou's map up- 
on which is shown the line of travel. The dotted line shows the 
northern escarpment of the Llano Estacado, which rises to the 
hio^ht of four or five hundred feet above the plain along which the 
line of travel is marked. The map shows the relative position of 
the hills under discussion. 
Now let the reader take this copy of Marcou's map and with a 
ruler draw a line touching the extreme northern limit of Marcou's 
Big Tucumcari, and his Mont Revuelto, and he will see that a 
straight line protracted will not again touch the line of travel af- 
ter having crossed it at the base of Marcou's Revuelto. From 
anywhere east of the Revuelto along the line of travel, according 
to his map, his Big Tucumcari cannot be seen. Revuelto of Mar- 
cou is a point of the Staked Plains and is as high as his Big Tu- 
cumcari. Of Revuelto he says: "It is the most prominent peak 
and the best landmark of the area and it is not easy to make a 
mistake with. " Being so prominent it of course hid from view 
from the east his Big Tucumcari. 
Second. — The form it presents when first seen in the distance. 
Gregg mentioned it as a round mound plainly visible from the 
north. Simpson mentioned it as a "well defined, truncated cone," 
and as they got nearer it resembled the dome of the capitol at 
Washington. 
That is exactly the appearance of the butte called Big Tucum- 
cari by me, but the other presents no such appearence when view- 
ed from any direction, and especially from the east as it cannot be 
seen ver}- far in that direction. 
Third. —T\xQ hight of the summit. Lieut. Simpson estimates 
the hight of the hill above the base at 700 feet. By repeated 
