The following table, taken from a manufacturer’s catalogue, shows the method of rating the heating capacity of a particular design. In the table, the first column gives the number of sections in the radiator, the second column states the length of the radiator in inches. The columns headed heating surface give the heights of the sections in inches and the amount of radiating surface in various radiators of different heights and numbers of sections. As an example: This table refers to the three-column radiators of Fig. 23. Such a radiator 32 inches high with 10 sections would contain 45 square feet of radiating surface and would be 25 inches in length. --------+--------+---------------------------------------------------- | | Heating surface--square feet | +--------+--------+--------+--------+--------+------- No. | Length | 45 in. | 38 in. | 32 in. | 26 in. | 23 in. | 20 in. of | 2½ in. | high, | high, | high, | high, | high, | high, sections| per | 6 sq. | 5 sq. | 4½ sq. | 3¾ sq. | 3¼ sq. | 2¾ sq. | section| ft. | ft. | ft. | ft. | ft. | ft. | | per | per | per | per | per | per | | sec. | sec. | sec. | sec. | sec. | sec. --------+--------+--------+--------+--------+--------+--------+------- 2 | 5 | 12 | 10 | 9 | 7½ | 6½ | 5½ 3 | 7½ | 18 | 15 | 13½ | 11¼ | 9¾ | 8¼ 4 | 10 | 24 | 20 | 18 | 15 | 13 | 11 5 | 12½ | 30 | 25 | 22½ | 18¾ | 16¼ | 13¾ 6 | 15 | 36 | 30 | 27 | 22½ | 19½ | 16½ 7 | 17½ | 42 | 35 | 31½ | 26¼ | 22¾ | 19¼ 8 | 20 | 48 | 40 | 36 | 30 | 26 | 22 9 | 22½ | 54 | 45 | 40½ | 33¾ | 29¼ | 24¾ 10 | 25 | 60 | 50 | 45 | 37½ | 32½ | 27½ 11 | 27½ | 66 | 55 | 49½ | 41¼ | 35¾ | 30¼ 12 | 30 | 72 | 60 | 54 | 45 | 39 | 33 13 | 32½ | 78 | 65 | 58½ | 48¾ | 42¼ | 35¾ 14 | 35 | 84 | 70 | 63 | 52½ | 45½ | 38½ 15 | 37½ | 90 | 75 | 67½ | 56¼ | 48¾ | 41¼ 16 | 40 | 96 | 80 | 72 | 60 | 52 | 44 17 | 42½ | 102 | 85 | 76½ | 63¾ | 55¼ | 46¾ 18 | 45 | 108 | 90 | 81 | 67½ | 58½ | 49½ 19 | 47½ | 114 | 95 | 85½ | 71¼ | 61¾ | 52¼ 20 | 50 | 120 | 100 | 90 | 75 | 65 | 55 21 | 52½ | 126 | 105 | 94½ | 78¾ | 68¼ | 57¾ 22 | 55 | 132 | 110 | 99 | 82½ | 71½ | 60½ 23 | 57½ | 138 | 115 | 103½ | 86¼ | 74¾ | 63¼ 24 | 60 | 144 | 120 | 108 | 90 | 78 | 66