THK STATE ENTOMOLOGIST. 



23 



which is attached to the 

 lower side of the arm 

 and curves over the out- 

 side of, and under, the 

 circle {g,g). 



These movable arms 

 are now arranged at 

 equal distances on the 

 circles, and fastened with 

 twine, while the canvas 

 is being tacked on, be- 

 ginning first by tacking 

 it to the sides of the plat- 

 form of the barrow and 

 then to the arms. At the 

 inner end of each of 

 these movable arms is 

 a raised finger (A, A), 

 which holds the canvas 

 up so as to keep any in- 

 sects from being thrown 

 over into the tree-way. 

 A semi-circular cog- 

 wheel (?', i), which works 

 by its centre, is now 

 placed on the lower end 

 of the same bolt that 

 passes through the inner 

 ends of the movable arms. The forward arm on each side is firm 

 ly attached to this cog-wheel, which works under the canvas. 

 When made to revolve backwards or forwards on the bolt, this cog- 

 wheel carries the outside arm around on the iron half circle, and the 

 sheet-covered frame is thus easily stretched and opened, as at j,j, or 

 closed as at k, k. 



This motion is quickly accomplished by means of a lever (I), 

 which works on a hinge at the rear of the platform, and which moves 

 a rod armed on one side at the forward end with cogs (m, m}, which 

 tread in the cogs of the semi-circular cog-wheel before described, to 

 which it is held by a keeper (n). The handle of the lever lies on the 

 platform when the machine is folded, and stands upright when it is 

 extended; so that by a single motion of one hand of the operator, the 

 machine may be folded into a very small compass, or as quickly ex- 

 tended. The hinder part of the machine is supported by two swing- 

 ing legs (<?, o). These may swing back to the handles, but cannot go 

 forward beyond a right angle. The machine is very light, and works 

 so easily that, according to the inventor, a boy of fourteen years can 



