A Simple Cone-Measuring Device

Quick and accurate measurement of the thousands of Douglas-fir cones collected for a study in correlation of size of trees, cones, and seeds necessitated the invention of the device described here. It was designed and built by two members of our shop crew, Albert Rieg and Arthur Hawks. We have found that it gives more accurate results than a hand ruler and that measurements take less time than with an ordinary caliper. The device can be adapted to measure cones of almost any size without modification. The device (fig. 1) is made of aluminum plate and channel. Detailed drawings are shown in figure 2. A piece of bar 3/8 inch thick, 1 3/4 inches wide, and 12 3/8 inches long is fitted into a section of channel 18 5/16 inches long and 1 3/4 inches wide inside. Sides of the channel are 1/2 inch high and 1/8 inch thick. The bottom of the bar is relieved 3/1000 inch, leaving 1/10 inch on each side to form runners, which greatly reduce friction. Both backstops are made of plate 4 inches wide, 3 11/12 inches high, and 3/8 inch thick. To set the stops over the channel, a piece 2 inches wide and 33/64 inch high is cut from the bottom of the stop, leaving a wing 1 inch wide on each side.

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Author(s): Lloyd Graham, Richard K. Hermann

Publication: Tree Planters' Notes - Volumes 19, Number 2 (1968)

Volume: 19

Number: 2

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