CONE-BEARING TREES 



1529 



CONE-BEARING TREES 



(a) Make a cone and a cylinder, of equal 

 base and altitude, of strong paper. Fill the cone 

 with salt, sand or sugar. Empty its contents 

 into the cylinder. Continue this until the cylinder 

 is filled. How many times did you empty the 

 cone of sand into the cylinder to fill the latter? 

 (Three times.) 



(b) Fill the cone with sand; fill the cylinder 

 with sand. Weigh them. How do their weights 

 compare? (1 to 3.) 



(2) The volume of a cone equals one-third the 

 product of the base and altitude. 



(a) If the altitude of a tent is 14 feet and the 

 area of the ground space is 153.9384 square feet, 

 how many cubic feet of air would it contain? 



(3) The area of the lateral surface (all of the 

 surface but the base) equals the circumference 

 of the base multiplied by one-half the slant 

 height. 



(a) John and Harry made a tent. The ground 



woods, larches and jumpers. The cone-shaped 

 fruit, with its heavy scales protecting the seeds, 

 suggested the name, although not all cone- 

 bearers (coniferae) bear cones. Some, like the 

 juniper, form berries. Another characteristic 

 peculiar to most of this pine family is the 

 slender, needlelike leaves, close-packed and 

 firm and so constructed as to endure cold. 

 Therefore, bearing leaves throughout the win- 

 ter, these trees have also earned the name 

 evergreen, although to this condition there are 

 a few exceptions. The tamarack sheds its 

 leaves each season. 



In forests, the scaly, fibrous trunks of cone- 

 bearing trees are bare a great distance up, and 

 then, as in all coniferae, the branches grow out 



White Pine Balsam Fir 



VARIATIONS IN CONES AMONG THE CONE-BEARERS 



space which it covered had a circumference of 42 

 feet, and the slant height was 16 feet. How many 

 square feet of canvas did they use? 



(4) To find the volume of the frustum of a 

 cone, multiply one-third of the altitude by the 

 sum of the areas of the two bases plus the square 

 root of their product. 



(a) How many gallons of water are there in a 

 tank having the shape of a frustum of a cone, 

 whose altitude is 6 feet and whose top and bottom 

 are respectively 20 % square feet and 27.04 square 

 feet in area? Use 231 cubic inches to the gallon. 



The problem last given suggests the practical 

 value of the mathematics of a cone. Given a ves- 

 sel in the form of a cone or frustum, its contents 

 in gallons or bushels may be determined by di- 

 viding the number of cubic inches in its contents 

 by the number of cubic inches in one gallon or 

 bushel. See GALLON ; BUSHEL. 



CONE-BEARING TREES, or CONIFERAE, 

 konif'eree, a commercially- valuable family of 

 trees and shrubs found in all temperate re- 

 gions, and occasionally at high altitudes in the 

 tropics. This family includes the familiar pines, 

 firs, hemlocks, cypresses, cedars, spruces, red- 



horizontally and diminish in length toward the 

 top, giving a conelike appearance to the whole 

 tree. Thus valuable poles and masts are ob- 

 tained from forests of cone-bearing trees. 



The wind plays an important part in the life 

 of cone-bearing trees. It carries the abundant 

 supplies of light, powdery pollen from tree to 

 tree to effect fertilization, and it bears the 

 winged seeds to new environments. Some spe- 

 cies are widely scattered; others, like the red- 

 woods of California, are found only in certain 

 localities. In some species the seeds are long 

 in ripening, and the scales cling firmly together 

 until the seeds are ready for their journey. 



Commercial Value. Besides furnishing the 

 most valuable timber trees, the coniferae also 

 produce vast quantities of resin, pitch, turpen- 

 tine and tar, and the products of some are 

 medicinal. In the lumbering industry the cone- 

 bearers have ever held first place, owing to 

 the lightness and durability of the wood, the 



