32 THE BOLL WEEVIL PROBLEM. 
the handles are pushed apart the front of the machine is spread 
wider, and vice versa. The braces j ¢ e serve to support, strengthen, 
and carry the front guard. They are riveted to the adjusting irons at 
j, one above and one below the “ shear ” pieces, to prevent their inter- 
ference with the closing of the machine. At ¢ this iron is bent to 
conform to the front guard, to which it is riveted between ¢ and 7, at 
which point it is bent downward and forms the hook e. Ordinary 
tire steel about 1 
by + inch may be 
used for all parts 
like the clevis 
(o p), rear arches 
(fhmandihg), 
and braces (k 1 
and j ¢ e). The 
front guard (a b 
c d) should be of 
spring steel, as 
specified. The 
rivet heads on 
the front guard 
should be round 
and fit smoothly. 
In nearly all 
other places the 
irons are fas- 
tened together 
by 4-inch square- 
headed bolts, with 
washers as needed. 
In operation the 
implement is 
drawn by a sin- 
ele animal. The 
Fic. 7.—Work of the chain cultivator : Cotton row before use of e¢hains at d and e 
cultivator, showing fallen squares, crack, and rough condition 
of ground. (Author’s illustration.) pass under _ the 
branches of plants 
and close to the stems. The forward motion of the machine causes 
these squares to be drawn inward by the chains, which must be kept 
taut, and leaves them in a narrow pathway where the chains approach 
within a short distance of each other at the opposite end of the 
machine. (See figs. 7, 8.) The two chains are provided so that 
squares that may pass over the first are taken up by the second on 
either side. In actual practice it has been found that more than 90 
per cent of squares may be brought to the middle of the rows. This 
512 
