PRACTICAL DIFFICULTIES OF BURNING OVER. 17 
the grass does not destroy the vitality of the eggs, and if delayed too 
long, the locusts would largely escape the dauger by flight. It is neces- 
sary, therefore, to prevent the old grass from being burnt during the 
winter, as was attempted in parts of Iowa and Minnesota in 1876-77. 
But it would be impossible to carry out a plan of this kind over the 
extensive area included in the bounds of the permanent regions. For 
in order to do this, it would be necessary, first, to know exactly where 
the egg deposits were made the autumn preceding the spring in which 
it was intended to put tlie plan into practice; next, it would be neces- 
sary to guard these areas carefully until the time for burning arrived to 
prevent them from being prematurely fired. 
But there are other reasons why this plan, which appears so com- 
mendable in theory, fails to accomplish the expected result when put 
into practice. 
First, the hatching is so uneven that it generally happens that some are 
acquiring wings by the time others are leaving the eggs. In the second 
place, there are few areas occupied by young locusts that the flames will 
sweep over without leaving gaps and unburned patches. 
In all the prairies and plains except a few such " dead flats " as the val- 
ley of the Red Biver of the North, there are innumerable little "breaks" 
or barren spots where the surface declines ; and these are the very spots 
the locusts select in which to deposit their eggs ; on such spots the young 
locusts chiefly congregate, and these are points the fire fails to reach. 
There are also numerous little depressions which the fire fails to reach, 
many little spots where the grass is too short or sparse to carry the flame, 
onward and thus breaks, and many points where the fire passes on so 
rapidly, simply burning the larger blades, that locusts are not killed. 
Thus, in various ways, a very large portion escapes, and the result, under 
what would appear to be most favorable conditions, falls far short of 
what is anticipated. 
Mr. Whitman, in his paper published in the appendix to our first 
report, remarks, speaking of the large deposit of eggs in 1876, that — 
This impending danger aroused the farmers to unusual exertions during the fall of 
1876. In counties where the trouble was an old one, conventions were held and meas- 
ures taken to prevent the prairie grass from being burned before the hatching season 
of 1877. To preserve this grass and fire it just at the time when the locusts were 
hatching seemed to be one of the most feasible methods of general destruction, and 
one which in past years had commended itself to the citizens of the infested counties. 
It was carried into effect in the spring in such a way as not to do all the good of which 
it was capable, or to show that it was impossible to produce anything like wholesale 
destruction, on a date specified beforehand, by this means. 
The writer of this chapter happened to pass through the southwestern 
part of Minnesota while the burning was going on. It was evident that 
the date chosen was too early, and hence the result in this case cannot 
fairly be cited as a test. In Northwestern Iowa the utmost precautions 
were taken by the authorities to give it a fair trial, but the undiminished 
2l 
