40 Origin, Extension and Continuance of Prairies. 
ed. The advantage of the algebraic process, consists in its simpli- 
_ city and in the universality of its application. This results from the 
circumstance that the meridian line not being limited in its position, 
may be made to pass through any station of the field, wherever 
it may be convenient to. commence either’ the measurement or the. 
calculation. . If its position is such as to divide the field into equal. or 
nearly equal parts, the multipliers or factors are lessened in quantity, 
and considerable labor is saved in the calculation, and the liability to 
error in the several computations ina —— degree dimin- 
ished. . en + 
——=—= 
Arr. VIII.—On the Origin, Extension and Continuance of Prairies; 
“extracted and abridged from unpublished MSS. on a theory of the 
mot + by Dr. Rusu Norv, of Rodney, State of eer 
“Wee can conceive that a prairie may proceed from the j font action. of 
two causes. First, from the influence of a cane-brake ; and secondly, 
from wind and fire. It has been shown that cane atents a considerable — 
influence on a forest of timber; that it can completely obscure the rays 
of the sun, as well as form by its roots an astonishing mat-work over — 
the face of the earth, so dense that it is utterly impossible for any 
seed to vegetate and for the earth to bring forward a single tree. 
Our knowledge of the natural history of the cane, does not enable 
us to know the length of time it is in seeding. More than half of 
the cane of a and Louisiana went to seed in the year 1830. - 
It had not seeded to such an extent, during the fifty preceding years. _ 
A few stalks or.a few square yards of the cane, seed and die every 
year, but when stalks seed again from the same root, we do not know 
whether so general a seeding as that just mentioned proceeded from 
natural or from accidental causes; such as long feeding up, ha the 
unusual vicissitudes of the weather of a few preceding 
stalk and root die with the ripening of the seed, which will vege 4 
and come forward the following year, unless prevented by sucha — 
drowth as followed the period alluded to. However, our want of a 
full knowledge of the natural history of the cane, is not very important — 
in the case before us, as we can readily conceive of a cane-brake 
contending with, and finally overcoming, extensive regions of forest 
trees. If the cané keeps possession of the same land for five han- : 
dred or a thousand years, (as we think it pes) it will of course wear 
fe 
