160 Report op the Botanist of the 



The unions are brass with ground joints and (liosc shown at w, 

 Fig. 4, which allow of the shear motion of the arms, are fitted 

 with set-screws to prevent unscrewing of the union. The hori- 

 zontal lengths of pipe shown in Fig. 3, were cut approximately 

 two feet long. The horizontal telescoping joints allow of closing 

 the carrier for four-foot rows, or of extending it for seven-foot 

 row*. The lengths of pipe which form the vertical supply pipe, 

 shown in Fig. 3 and Fig. 4, also those which form the arms, were 

 cut approximately 18 inches long. The telescoping of the arms 

 combined with the shear motion is an essential feature in adjust- 

 ing the nozzles for different heights and widths of rows. It is 

 still an open question whether the vertical telescoping joints 

 shown at f are of any real merit. One point is certain, the use' 

 of a telescoping joint in the vertical supply pipes which carry the 

 arms necessitates extra fixtures and adds to the weight. The 

 rods shown at r, Fig. 3, were provided to prevent twisting and 

 slipping of the arms on the above joints, but as these proved 

 more ornamental than useful for this purpose, an iron bar, shown 

 at 6, Fig. 4, was added. The latter prevents the twisting; it also 

 strengthens the leverage for lifting the arms when turning 

 around; at the same time it prevents sliding of the vertical joints. 

 By the use of the above bar, the rods shown at r, Fig. 3, are not 

 essential. 



At first the elbow put out with the " Erin " nozzle by the Gould 

 Manufacturing Company, was used for attaching the nozzles. 

 These proved to be too weak for practical use so were abandoned 

 and eighth-inch ground brass unions substituted. By the use of 

 a short piece of bent tubing these unions gave nearly as much 

 freedom of direction as did the elbows. At the same time the 

 unions would turn before breaking or wrenching off, but could 

 be screwed tight enough to hold the weight of the nozzle. 



The size of tubing used in arms was one-eighth inch, telescop- 

 ing into one-half inch, iron pipe sizes. The vertical supply pipes 

 consisted of one-inch pipe telescoping over three-fourths inch 

 pipe. The latter is not iron pipe size. The same dimensions 



