PRAIRIE FIRES. 69 
dozen rods in width, since their valley sides are often grassy down 
to the water’s edge. In such cases, woe to the traveller who may 
be unprepared for, or may lack nerve to meet the emergency. If 
he has a box of matches and ordinary coolness of judgment he is 
in no personal danger, for he has only to stop and set another 
fire, extinguish that part of it upon the windward side before it 
has increased beyond his control, and pass into the space that has 
been burnt free from grass by his own fire, where he is safe from 
the advancing flames that have given him the alarm. Some dan- 
ger, however, always remains that his animals may take alarm 
from his own fire, and become unmanageable, but usually their in- 
stinctive dread, and a sense of dependence upon their masters, 
which horses constantly feel and manifest upon those lonely jour- 
neys, render them usually quite tractable under such circumstances. 
hile prosecuting the Geological survey of Iowa, we were often 
exposed to danger from fires when having occasion to cross the 
broad prairie region of the western part of the state. One Octo- 
ber day after the first frosts of the season had killed the herbage, 
and the subsequent warm days had rendered the prairies almost 
like oné vast tinder-box, the approach of night found us a few 
miles from a stream, the valley of which was distinctly in view as 
well as the broad prairie stretching beyond it. Mosquitoes are 
abundant in the valleys at this time of the year, and being appar- 
ently conscious that their end is approaching, they seem determined 
to get the greatest amount of blood in the shortest possible time 
from every living thing that comes in their way. We, therefore, 
stopped as usual, upon elevated ground, to camp where the breeze 
would prevent their visit. . Procuring water for the camp, and 
watering our horses at a rill near by, we pitched our tent where we 
could overlook the surrounding country, and mowed the grass from 
a space of a few square yards upon which to build our camp fire of 
the few sticks we had brought from our last camping ground. Our 
supper over, and the horses picketed upon the grass that was still 
fresh by the rill, we lay down to sleep. The wind had been high 
all day, and did not abate upon the approach of night as it. usually 
does. As it began to grow dark, I had observed in the distant 
horizon the light of a prairie fire. It was directly to the windward, 
and the face of the country in that direction was known to be such 
that nothing would be likely to arrest its progress towards us, ex- 
cept the stream before mentioned, and this I feared was too narrow 
