20 BULLETIN 229, U. S. DEPARTMENT OF AGRICULTURE. 



will be 12 inches from the ground (Plate III, fig. 2). In Plate IV, 

 figure I, the first streak is 17 inches higher than necessary. On the 

 basis of one-half inch streaks this means that a height sufficient for 

 34 chippings, or for a whole season, has been lost. 



Class 2. (Plates V and VI.) The gum flowing from the face is 

 guided into the cup by means of a flat oblong piece of galvanized 

 iron, with the ends slightly upturned, called an " apron." The edge 

 of the apron to be inserted in the tree is concave to conform to the 

 tree's shape. In some cases the aprons are made in two pieces, 

 riveted together at the ends, so as to allow them to be adjusted to 

 the curvature of each particular tree. They are also made in two 

 separate pieces. The aprons are inserted in a horizontal gash at the 

 base of the tree made with a broadax having a flat blade with a 

 concave edge. When inserting the apron a small blaze about 6 

 inches wide and 2 inches high is generally made to remove objection- 

 able bark. The broadax is held horizontally against the blaze, 

 with the head slightly downward, by one man, while another drives 

 it into the tree with a maul. The ax is then withdrawn and the 

 apron inserted. 



A recently introduced apron is lunar in shape, the concave edge 

 being provided with stiff teeth. This apron can be driven directly 

 into the tree, obviating the necessity of blazes or gashes. 



The cups are made of galvanized iron or clay and hold about a 

 quart. Their general shape is that of an oblong box 12 inches by 3 

 inches at the top, and about 3 inches deep. They are slightly larger 

 at the top than at the bottom, and are sometimes shaped to con- 

 form to some extent to the curvature of the tree. The cups are 

 sometimes hung from the apron by means of small hooks which 

 engage an extension on either end of the apron, or they may be 

 supported on a nail driven into the tree beneath the apron. The 

 likelihood of the fasteners becoming clogged by gum is obviated by 

 the use of nails as supports. In hanging this class of cups large 

 blazes are not necessary, and if properly hung practically all the 

 gum -flowing from the tree reaches the cups. As the aprons occupy 

 but little vertical space and the cups are comparatively shallow, a 

 distance of 12 inches from the ground to the first streak is ample on 

 normal trees (Plate V, fig. 1). In the case of small trees 10 inches 

 or less in diameter, the use of the 2-piece or riveted apron allows a 

 shallower cut to be made in hanging the cup, as the 1-piece aprons 

 have such a large curvature that they require a deep cut in small 

 trees (Plate VI, fig. 1) to prevent escape of gum at the sides. On 

 large timber, of course, this difficulty does not occur. 



Class 3. (Plate VII, fig. 1.) The cup is so constructed as to obviate 

 the necessity of using a gutter or apron. In order to hang it, several 



