The character of the harvesting equipment may vary considerably, depending on the acreage, character of trees and ground, time required, capital available, and the personal wishes of the owner. Some growers use heavy poles of pine, spruce or fir, while others prefer the lighter bamboo poles. The heavy poles are from 1½ to 2 inches in diameter at the base and from ¾ to 1 inch in diameter at the top. Experience has shown that poles of this type over 20 feet in length become unwieldy, and not only swing slowly but do more damage because of the greater difficulty of control. Most growers prefer 16-foot poles with a few 20-foot ones for use in the tops of the taller trees. Where the tops cannot be reached with these, the men climb into the trees with shorter poles. The bamboo poles used are about 24 feet long and because of their lightness can be used with greater speed. Bamboo poles with short internodes should be selected as they are less likely to break. Breakage may also be reduced by storing the poles in a cool place where drying-out will not be excessive. The sheets used are made of duck ranging in weight from 7 to 12 ounces. Sizes of single sheets range from 12 × 24 to 24 × 48 feet. Sheets need not be much longer than the longest diameter of the tree. To prevent mildew and rotting of the fabric in the sheets they should be boiled in a solution of tannin before being used. The life of sheets thus treated will be greatly lengthened. A number of growers have provided special contrivances by which sheets are mounted on sleds or wheels so they are not dragged on the ground. The principal objection to such an arrangement is that the sled or wheeled frame must be made in two sections, one for each side of the tree, thus increasing the cost of the operation because the horses can be used for nothing else while harvesting is in progress. On the other hand, by the dragging process sheets will not last more than two or three seasons, whereas by the sled or wagon method they will last from six to ten years longer. The two wagons shown in figure 21, each 12 × 24 feet, cost between $60 and $70, about 1914. The canvas portion is of 8-ounce duck. By this method the knockers can gather ten lug boxes before emptying. The work can be done much faster with wagons. With the sleds a sheet is fastened lengthwise on the right-hand side of one and another on the left-hand side of the other sled.