TESTS OF MACHINERY FOR KILLING COTTON WOl 



sary for this purpose. The field laborer of the South -«reu> up the joint 

 to<> tig-lit, too loose, or in such form as to spoil the screw-threads. Again, 

 the joints become rusted together and a viae must be engaged. The 

 stiff system also requires that very heavy pipe be used, as the lev. 

 on long pipe arms enables them to suffer great strain, to become broken 

 off easily at the end where the thread for the joint is cut. whereas with 

 flexile joints no leverage power but only tensile strain can be brought to 

 bear. In the latter case very light tubing can be employed with economy 

 in material, cost, labor, and salvage of cotton. Moreover, only by such 

 light flexile apparatus can any considerable number of rows be treated 

 at once from beneath. These facts have been substantiated by tests of 

 stiff and of flexile apparatus this season more fully than they wer<* by 

 the Atlauta tests, in which one light machine undersprayed eighteen 

 rows of cotton, a strip twenty yards wide, at a single drive. The tests 

 this year have been not only of stiff connections, but also of the con- 

 structions whereby adjustability of the descending pipes is effected au- 

 tomatically and by hand. These have already been noticed above or 

 in the previous reports in so far as they pertain to the stem or body of 

 the pipe or its distal appendages : hence, next in order may be consul 

 more specifically and in natural sequence the construction and arrange- 

 ments of the tops of these pipes as planned and tested by me: 



I. The stiff hanging tubes have been tried, as already set forth, in 

 firm union with a stiff back-pipe or cross-pipe such as appears in many 

 of the patented sprayers, as Johnson's. Daughtrey's. etc.. while suffi- 

 cient objections to this arrangement for underspraying have already 

 been presented. It is the first construction which naturally su^_ 

 itself to any plumber or other mechanic, but presents no special adap- 

 tation for the purpose, as has been shown this season and previously. 



II. The extremest opposite construction to the foregoing is attained 

 by having radiating flexile tubes from the main to the descending pipes, 

 instead of a straight and stiff cross-pipe. By this arrangement the 

 hanging pipes are swung apart or nearer together independently, and 

 set on a cross-bar or on diverging bars, at spaces to suit rows having 

 different courses or widths. 



By way of variation the tubes may radiate only for a part of the 

 distance, and for a space run close beside each other along a supporting 

 bar before reaching the descending parts. The parts upon the support 

 are preferably of metal, and slide readily in peculiarly locked hooks, as 

 simple, easily separable attachments, specially devised for this purpose. 

 Where the descending parts have flexibility to sonic extent they may 

 drag in the cotton in turning, as stated above. It is shown that they thus 

 do no' noteworthy harm to the plants: also that they themselves do not 

 sutler injury. This flexile construction is simple, and generally preferable 

 in combination with the flexile connectives between their tops. But 

 should any prefer that the hanging parts be elevated above the plants in 

 turning, this is easily done. Tor such purpose, and to shorten the lever- 



