16 
impervious for a time to sudden heat. Some minutes are required to 
destroy them utterly. An ordinary brush fire merely scorched the 
outside layer and killed a few of the outside eggs. Next, experiments 
were made with crude petroleum, spraying it over the ground and 
igniting it, but this was not perfectly effective. Continued experi- 
ments were made with different methods. A remarkable apparatus 
was constructed to distribute inflammable oil in a spray which devel- 
oped wonderful combustive powers. Many substances, both liquid 
and gas, were experimented with to destroy the eggs, and a series of 
interesting implements were invented in the way of hand mirrors to 
assist in searching for the eggs, and knives. and scrapers for removing 
them and destroying them. 
It resulted from this experimental work that creosote was found to be 
the best substance for egg destruction, and the present method consists 
in thoroughly painting each egg mass found with a cheap creosote oil. 
There are great difficulties in the way of economically and rapidly apply- 
ing this remedy. The eggs must be searched for in inconceivable crev- 
ices, trees must be climbed and egg clusters, which can not be reached 
by hand, must still be painted by means of brushes attached to the 
extremities of long poles. The process, however, is carried on very 
effectively and much more rapidly than would be supposed. The men 
employed have become so trained in the discovery of eggs that they 
will see them instantly, even at the tops of tall trees, where they would 
be entirely unnoticed by nonexperts. A gang of men will proceed 
rapidly through a bit of woodland, treating the egg clusters in this 
way, and it is safe to say that after they have finished, and after the 
still keener eyed inspectors have followed up, the number of potential 
caterpillars has been reduced to a minimum. 
After the eggs have hatched, the new method of work is at once 
introduced. According as conditions vary in different localities the 
director of field work has varied his method of treatment. Thus, in the 
case of some colonies where the eggs were numerous, but concentrated 
within a comparatively small space, it has been considered advisable 
to allow them to hatch, and the work of destruction has in such cases 
been directed exclusively against the caterpillars. Where, however, 
the egg masses were more or less scattered, every effort has been made 
to prevent the appearance of the caterpillars by destroying the eggs. 
Against the caterpillars themselves several kinds of work have been 
carried on — the spraying previously mentioned and two methods of 
banding the trees. The first consists in placing around the trunk of 
the tree a viscid sticky band, either tar paper or fish oil, or the sticky 
German product known as a raupenlehn " (caterpillar glue), applied 
directly to the bark. This substance, which has been used with good 
effect in Europe against the Gipsy Moth caterpillar and against the 
even more numerous and destructive larva of the nun moth, remains 
viscid for many months, and is very effective for the purpose for which 
