=10.= A house as large as the one under consideration should be heated either by steam or by hot water. However, a furnace is used in this case, not because it is the best practice, but because it gives practice in estimating on a furnace, which is more important than estimating on either steam or hot water. In taking off quantities for the heating and ventilating contract, attention should be given to the fact that the furnace and pipes, registers and borders, and the fireplace furniture are usually supplied by different manufacturers. FURNACE _Quantities and Cost_ One 53-inch cast-iron portable furnace set up in place $125.00 WARM-AIR AND SMOKE PIPES _Quantities and Cost_ 12 ft. of 4" × 8" tin W. A. pipe, at 12½ cents $ 1.50 12 ft. of 3" × 12" tin W. A. pipe, at 15 cents 1.80 13 ft. of 4" × 10" tin W. A. pipe, at 15 cents 1.95 61 ft. of 10-inch round tin W. A. pipe, at 16 cents 9.76 12½ ft. of 8-inch round tin W. A. pipe, at 12½ cents 1.56 4 ft. of 8-inch galvanized-iron smoke pipe, at 15 cents .60 17 ft. of 10-inch round, fireclay flue lining, at 25 cents 4.25 2½ ft. of 8-inch round, fireclay flue lining, at 20 cents .50 Labor, one-half of cost of materials 10.96 ------- Total $ 32.88 REGISTERS _Quantities and Cost_ Three 14" × 16" japanned floor registers and borders, at $3.85 $ 11.55 One 7" × 10" japanned floor register and border .85 One 12" × 15" japanned floor register and border 2.25 Two 7" × 9" japanned floor registers and borders, at 85 cents 1.70 One 10" × 12" japanned floor register and border 1.26 Two 12" × 15" japanned wall registers and borders, at $2.25 4.50 One 10" × 12" japanned wall register and border 1.26 Labor, one-third of cost of materials 7.79 ------- Total $ 31.16