APPENDIX III. 205 



The Anderson Coal-Oil Contrivance. 

 {See Fig. 18.) 



This contrivance was constructed by President John A. Andersen, 

 for use on the Agricultural College Farm, at Manhattan, Kansas 

 It was found to do very good service, killing tlie young locusts in 

 considerable numbers. The oil did not evaporate so rapidly as waa 

 anticipated. One thorough saturation was sufficient for fifteen or 

 twenty minutes, when a little more could be added. If the machine 

 be hauled against the wind nearly all the locusts which hop will touch 

 the oiled canvas. They generally take several hops upon the canvas 

 before leaving it, thus insuring a thorough saturation with the oil. 

 After hopping from the apron they can take two or three hops upon 

 the ground, then lose all power in their hind legs, stretching them 

 straight out behind, and finally, in one or two minutes after being 

 " oiled " they are dead. 



Coal Tar. — This may be used with most of the contrivances just 

 described for the use of kerosene, and while not equal to the simple 

 kerosene pan for speed in trapping and destroying, is yet very useful, 

 especially where the coal-tar can be obtained at nominal cost from gas- 

 works. It also permits the use of the simplest kind of pan. Enough 

 tar is spread over whatever receptacle may be used to cover well the 

 bottom, and when this becomes sufficiently matted with the young 

 locusts so as no longer to destroy the new comers, another coating is 

 added, and so on until it becomes necessary to remove the whole mass, 

 when it is shovelled from the pan and burned ; or, what is far prefer- 

 able, wherever there are wet ditches it may be thrown into these, when 

 the oil contained in it, spreading over the surface of the water, destroys 

 such locusts as may jump into or be driven into such ditches. Where 

 the tar is scarce, as a matter of economy it will pay to melt the accu- 

 mulated mass in iron vessels. By skimming off the dead locusts that 

 rise to the surface, and thinning the residuum with a little coal-oil, it 

 may be used again. 



The Robbins Coal-Tar Pan. 

 {See Fig. 19.) 

 A simple pan extensively employed, and which is known as the 

 Robbins " hopperdozer," is shown, the general plan being that of 

 the ordinary road-scraper. ' Its simplicity and durability account 

 for its general use. It was usually drawn by hand, though several 

 pans were frequently bound together and drawn by horses ; while, in 

 some instances, certain improvements in the way of mounting on 

 wheels, so as to permit its being pushed from behind, were also adopted. 

 We saw some with a wire screen or cover hinged to the back, so that 

 the insects might be secured when the pan was not in motion, but the 

 cover seemed superfluous. We also saw lime and kerosene mixed so as 

 to form a mortar substituted for the coal-tar. 



