CONDUITS, PORTAGE, ETC. 
291 
the main pipe oft he Y-fork. This main may be of any practical length 
as a pipe, or cau be short enough to be regarded only.as a coupling 
]»avt. The angle coupling-piece proper, indicated by ?/, can be vari- 
ously made. For example, a solid piece may be bored with three con- 
verging intercepting holes, or these passages can be cored out in a 
casting. The piece may have any suitable form or weight. It should 
bo rounded in front and rather smooth in order not to catch or hang 
upon vines or other bodies, and it may have a basal lobe extending 
back beneath or to the sides to prevent injuries to the parts, c j //. 
These parts, as a rule, are not necessarily to be protected. But I have 
sometimes added a thin sheet-metal plate with more or less up turned 
sides, while it is firmly attached or hung loose, as in Plate XXXIX, 
Fig. 3 ej. Coupling-nibs, t j j, are screwed or sweated into the angle- 
piece, y. I also have planned other fork constructions, and one is shown 
in Plate XXXIX, Fig. f>. This style works excellently, and probably 
oilers about the least resistance possible to the inside current. It 
consists of two curved tubes, j j, cut and matched together its shown, 
one-halt* being cut from one end of each and (he two half ends are 
united side to side to form the single entrance to the two diverging 
parts. Such a fork is both strong and light. In the angle y can be 
inserted a filling or brace to increase its strength. Probably the easiest 
way of joining tubes to form the angle -piece is that shown in Plate 
XL IX, P|g. 4, as a simple right angle T-tube. In this e represents the 
sheath-couplings of rubber hose. When this method of coupling is 
used the ends of the tubes should be slightly flared or grooved 01 an- 
nulated on the outside to keep the hose and wire wraps from being polled 
off. When desired metallic joints can be made at these places. Such 
are shown in combination with the reverberators chamber-fork in Plate 
XLIX, Fig. 3, where the outside flange of the end of the arm-piece is 
Clamped against the center-piece (or an intermediate packing-ring) by 
the inside llange of the nut. This gives the joint freedom of rotation. 
The other essential parts of this figure need no farther explanation here. 
The central chamber there appearing is of more special value as an equal- 
iser in distributing blasts laden with powders or liquids. 
Th.> pair of arm-tubes, e i 7i, may extend from their focus, forming T- pipe 
branches, or they may be set at any suitable angle with each other or with 
their main as Y-pipe branches, and they can have any length that is 
practical. These branches may he entirely st iff, or partly or entirely 
flexible or elastic. When stiff, if continued straight throughout their 
length, the distal portions especially will be liable to catch upon obsta- 
cles and upon the plants, to injure the latter or cause the pipes them- 
selves to be damaged by breakage or bending. To prevent these lateral 
branches from mutilation or mutilating I have generally directed them 
wholly, or at least their distal portions, in a somewhat backward man- 
ner. Such a stiff form is shown in Plate XLIX, Fig. G, where each arm 
has a regular backward curve. The arms are joined by a regular T- 
