CONDUITS, PORTAGE, ETC. 
293 
ing or repairing theua. It was for these reasons that I first used flexile 
systems of tubes and eheap apparatuses to be tested. When they trail 
upon the ground they are not affected by its irregularities, nor do they 
cateh upon the plants to receive or give injury, hut conform easily to 
all changes of the ground or the rows. In turning in the eottou the 
hanging flexile forks drag through among the plants, and when the ap- 
paratus is turned short on only two wheels so tbat one of its sides 
swings somewhat backwards while the other goes around, or when the 
machine is backed by any accidental or intentional movement of the 
horses in the cotton, the forks are not pushed into or against the plants 
iu the injurious manner which might result were the stem and branch 
pipes entirely stiff ; but in such cases the pliable pipes bend while the 
lower part of the fork does not move or else is dragged backward with 
no possible harm. But in order that the wheels in turning do not run 
onto the fork-arms if lying on the grouud, these must be suspended 
from safe points either before or behind the wheel, or at such a distance 
to one side from the wheel that it cannot be turned forward or backward 
to roll upon the arms. The peculiar disposition ol the parts in the A- 
frame machines shown in the plates is such as to insure safety in these 
respects. It should also be added that block-tin pipes and copper or 
lead tubes are valuable on account of their being less subject to corrosion, 
but the softness or pliability of these metals allows such tubes to bend 
easily, hence, where employed, they should be attached at short in- 
tervals upon some rigid support or have a still" internal rod such as I 
have introduced in hose to maintain it in such direction, course, or po- 
sition as may be wished. Zinc does not rust, but is most easily cor- 
roded by anything of an acid nature. It will generally be preferred to 
common tin, but is somewhat softer and breaks more easily. Such pipe 
systems can be used with any kind of poison receptacle or with any 
forcing medium, such as a force-pump, bellows, gas-pressure generator, 
or a gravitating column of liquid. 
For pipe-systems of stiff, flexible, or flexible-jointed tubing, embrac- 
ing forks of the kinds just described, to be carried or trailed through 
the held, I have combined groups of various sizes, including two or 
more of the forks, and some different means of support and conveyance 
of the same need to be considered here. The old-fashioned way of giv- 
ing support to the primary or main trunk-branches of tubes by attach- 
ing them to the real' horizontal parts of any suitable vehicle, to some 
frame, bar, or box upon the same, is naturally the simplest; but adjust- 
ability to suit row-spaces of different widths is desired, and different ar- 
rangements with these should be adopted. As illustrating this topic the 
following machine should be noticed. This machine was planned by me 
and tested to show a possible adjustability and the possible width that 
might be embraced in one of these machines. Plate XLVII exhibits;! 
rear view of this apparatus as cut from a, photograph of it taken to 
show its operation in the field. The cotton being unusually small and 
