CONDUITS, PORTAGE, ETC. 291 



the main pipe ofthe Y-fork. This main may be of any practical length 

 as a pipe, or can be short enough to be regarded only as a coupling 

 part. The angle coupling-piece proper, indicatetl by y^ 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 

 be 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, e j y. 

 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. Goupling-nibs, tjj, are screwed or sweated into the angle- 

 piece, y. I also have jilanned other fork constructions, and one is shown 

 in Plate XXXIX, Fig. 5. This style works excellently, and probably 

 offers about the least resistance possible to the inside current. It 

 consists of two curved tubes, jj, cut and matched together as shown, 

 one-half being cut from one end of each and the 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 

 XLIX, Fig. 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 or an- 

 nulated on the outside to keep the hose and wire wraps from being pulled 

 off. When desired metallic joints can be made at these places. Such 

 are shown in combination with the reverberatory 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 flange of the nut. This gives the joint freedom of rotation. 

 The other essential parts of this figure need no further explanation here. 

 The central chamber there appearing is of more special value as an equal- 

 izer in distributing blasts laden with powders or liquids. 



Th?. pair of arm -tubes, ein, 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 be entirely stiff, 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. 6, where each arm 

 has a regular backward curve. The arms are joined by a regular T- 



