88 STODIES OK SERODENTS 
his term ‘ baselevel.” A name had already been suggested for 
the balanced condition by various writers, who called it the 
“régime” or “regimen” of rivers, while the slope of a river 
under this regimen was called its ‘“penté d’éguilibre” by Dausse 
and the ‘ Erostons-Terminante”’ by Philippson (1886, 71.) But 
(1857, 759) “regimen” 
of river action under which the balanced condition is developed 
may be better used as meaning the rule 
and maintained; while ‘slope of equilibrium” may be taken 
as a descriptive phrase, too cumbersome for ordinary or fre- 
quent use, but essentially synonymous with ‘graded slope.” 
‘‘ Baselevel ”’ seems at best a very inappropriate name for a con- 
dition in which the idea of slope is essential; and when another 
and equally important use is made of this excellent word, its 
employment as the name for the balanced condition of rivers is 
all the more unsatisfactory. ‘‘ Grade” is the most satisfactory 
term for the balanced condition or state of equilibrium of rivers 
on several grounds, in spite of certain objections that may be 
urged against it. Let us consider the objections first. 
Origin and use of the term “‘grade.’—One of my correspond- 
ents has objected to “grade” because, in the sense here adopted, 
the word means, etomologically, a step and nota slope. This 
objection seems to me of small value on account of the freedom 
with which new meanings are given to old roots. Language 
does not grow by rule but by use; and use has decreed that one 
meaning of the English word ‘‘grade”’ shall depart somewhat 
from the meaning of its Latinancestor. The chapter on ‘Trans- 
ference of Meaning” ‘ina work on Words and Their Ways in 
English Speech, by two of my colleagues, Professors Greenough 
and Kittredge, may be consulted to advantage in this con- 
nection. 
Another correspondent objects because the word ‘‘ grade” 
is already in common use, meaning among other things, a slope, 
and the ratio of the vertical to the horizontal in a slope; but as 
a matter of fact no practical inconvenience has arisen on this 
account. The context suffices to indicate which one of the 
several meanings of the word is intended. Moreover, if we 
