713| 1876| 2027| 2167| 2298| 2423| 86 |
| 102 | 56.75|1739| 1824| 1944| 2130| 2300| 2459| 2609| 2750| 91 |
| 108 | 63.62|1959| 2054| 2190| 2392| 2592| 2770| 2939| 3098| 98 |
| 114 | 70.88|2192| 2299| 2451| 2685| 2900| 3100| 3288| 3466| 101 |
| 120 | 78.54|2438| 2557| 2726| 2986| 3226| 3448| 3657| 3855| 107 |
| 126 | 86.59|2697| 2829| 3016| 3303| 3568| 3814| 4046| 4265| 112 |
| 132 | 95.03|2970| 3114| 3321| 3637| 3929| 4200| 4455| 4696| 117 |
| 144 |113.10|3554| 3726| 3973| 4352| 4701| 5026| 5331| 5618| 128 |
| 156 |132.73|4190| 4393| 4684| 5131| 5542| 5925| 6285| 6624| 138 |
| 168 |153.94|4878| 5115| 5454| 5974| 6454| 6899| 7318| 7713| 150 |
|______|______|____|_____|_____|_____|_____|_____|_____|_____|_______|

Kent's Stack Tables--Table 55 gives, in convenient form for approximate
work, the sizes of stacks and the horse power of boilers which they will
serve. This table is a modification of Mr. William Kent's stack table
and is calculated from his formula. Provided no unusual conditions are
encountered, it is reliable for the ordinary rates of combustion with
bituminous coals. It is figured on a consumption of 5 pounds of coal
burned per hour per boiler horse power developed, this figure giving a
fairly liberal allowance for the use of poor coal and for a reasonable
overload. When the coal used is a low grade bituminous of the Middle or
Western States, it is strongly recommended that these sizes be increased
materially, such an increase being from 25 to 60 per cent, depending
upon the nature of the coal and the capacity desired. For the coal
burned per hour for any size stack given in the table, the values should
be multiplied by 5.

A convenient rule for large stacks, 200 feet high and over, is to
provide 30 square feet of cross sectional area per 1000 rated horse
power.

Stacks for Oil Fuel--The requirements of stacks connected to boilers
under which oil fuel is burned are entirely different from those where
coal is used. While more attention has been paid to the matter of stack
sizes for oil fuel in recent years, there has not as yet been gathered
the large amount of experimental data available for use in designing
coal stacks.

In the case of oil-fired boilers the loss of draft through the fuel bed
is partially eliminated. While there may be practically no loss through
any checkerwork admitting air to the furnace when a boiler is new, the
areas for the air passage in this checke