240 



HEATING AS APPLIED IN HORTICULTURE. 



duct divided by 222, will give the num- 

 ber of feet in length, of pipe 4 inches 

 diameter, which will produce the desired 

 effect." If 3-inch pipes be used, then 

 the number of feet of 4-inch pipe must 

 be multiplied by 1.33; and in regard to 

 2-inch pipes, the number of feet of 4-inch 

 pipe is to be multiplied by 2 ; — the 

 length of 3-inch pipe being one-third, and 

 the length of 2-inch pipes being double 

 that of 4-inch, the temperature being all 

 the same. 



Mr Neeve, long principal assistant to 

 the late Mr Tredgold, asserts that he 

 proved by calculation that a boiler 3^ feet 

 long, 1 foot 2 inches deep, 1^ feet wide, 

 and 178 feet lineal of 4-inch pipe, would 

 be quite sufficient to heat a peach-house 



containing 7600 cubic feet of air to 55°, 

 supposing the external temperature to be 

 as low as 20° Fahrenheit scale. 



The following table has been drawn up 

 by Mr Hood, and cannot fail of being 

 acceptable to all those interested in heat- 

 ing. 200° Fahrenheit is the assumed 

 heat of the pipes in this table, that being 

 the temperature at which they can most 

 easily be maintained. " When the quan- 

 tity of air to be warmed per minute is 

 greater or less than 1000 cubic feet, the 

 proper quantity of pipe will be found," 

 Mr Hood observes, " by multiplying the 

 length given in the table, by the number 

 of cubic feet of air to be warmed per 

 minute, and dividing that product by 

 1000." 



Table of the Quantity of Pipe, 4 inches diameter, which will heat 1000 cubic feet of air 

 per minute any required number of degrees, the temperature of the pipe 

 being 200° Fahrenheit. 





Temperature at which the Room is required to i 



3E KEPT. 



Temperature of 











































External Air. 



45° 



50° 



55° 



60° 



65o 



70° 



75° 



80° 



85° 



90° 







Feet of Pipe required for One Thousand feet of A 



ir. 





10° 



126 



150 



174 



200 



229 



259 



292 



328 



367 



409 



12° 



119 



142 



166 



192 



220 



251 



283 



318 



357 



399 



14° 



112 



135 



159 



184 



212 



242 



274 



309 



347 



388 



16° 



105 



127 



151 



176 



204 



233 



265 



300 



337 



378 



18° 



98 



120 



143 



168 



195 



225 



256 



290 



328 



368 



20° 



91 



112 



135 



160 



187 



216 



247 



281 



318 



358 



22° 



83 



105 



128 



152 



179 



207 



238 



271 



308 



347 



24° 



76 



97 



120 



144 



170 



199 



229 



262 



298 



337 



26° 



69 



90 



112 



136 



162 



190 



220 



253 



288 



327 



28° 



61 



82 



104 



128 



154 



181 



211 



243 



279 



317 



30° 



54 



75 



97 



120 



145 



173 



202 



234 



269 



307 



32° 



47 



67 



89 



112 



137 



164 



193 



225 



259 



296 



34° 



40 



60 



81 



104 



129 



155 



184 



215 



249 



286 



36° 



32 



52 



73 



96 



120 



147 



175 



206 



239 



276 



38° 



25 



45 



66 



88 



112 



138 



166 



196 



230 



266 



40° 



18 



37 



58 



80 



104 



129 



157 



187 



220 



255 



42° 



10 



30 



50 



72 



95 



121 



148 



178 



210 



245 



44° 



3 



22 



42 



64 



87 



112 



139 



168 



200 



235 



46° 





15 



34 



56 



79 



103 



130 



159 



190 



225 



48° 





7 



27 



48 



70 



95 



121 



150 



181 



214 



50° 







19 



40 



62 



86 



112 



140 



171 



204 



52° 







11 



32 



54 



77 



103 



131 



161 



194 



%* To ascertain by the above table the quantity of pipe which will heat 1000 cubic feet of air 

 per minute, find, in the first column, the temperature corresponding to that of the external air, 

 and, in one of the other columns, find the temperature of the room; then, in this latter column, 

 and on the line which corresponds with the external temperature, the required number of feet of 

 pipe will be found. 



