Flytraps and Their Operation. 7 



The construction of a cone of any given height or diameter is 

 quite simple if the following method be observed. It is best to cut 

 a pattern from a large piece of heavy paper, cardboard, or tin, 

 Figure 3 illustrates the method of laying out a cone of the proper 

 dimensions for the above trap. An ordinary square is placed on 

 the material from which the pattern is to be cut; a distance (22 

 inches) equal to the height of the cone is laid off on one leg of the 

 square at A, and a distance (9 inches) equal to one-half of the 

 diameter of the base of the cone is laid off on the other leg at B, 

 and a line is drawn between the points A and B. With the distance 

 between these points as a radius and with the point JL as a center, 



Fig. 3. — Method of laying out a pattern for the construction of a cone. Cut out on 

 curved line C to E and on dotted lines from A to C and A to E. 



the portion of a circle. C D, is drawn. With a pair of dividers, the 

 legs of which are set 1 inch apart, or with the square, lay off as many 

 inches on the arc O Z>, starting at C, as there are inches around the 

 base of the cone, which in this case is about 564 inches, reaching 

 nearly to the point E. Then add one-half inch for the lapping of 

 the edges of the cone, and one-half inch which is taken up when the 

 cone is tacked in, thus making a total distance from to E oi 57^ 

 inches. Draw a line from .1 to C and another from A to E, and cut 

 out the pattern on these lines and on the arc from C to E, as shown 

 in figure 3. The edges AC and AE are then brought together, lapped 

 one-half inch, and sewed with wire or soldered. After the aperture 

 of the cone is formed by cutting off the apex, as previouslj'^ described, 

 it is ready for insertion in the trap. 



