134 HOT-HOUSE. 



house. The greatest difficulty is to have the furnace to 

 draw well. As workmen are not generally conversant on 

 the subject, nor yet understand the effect or distribution of 

 heat in these departments, we will give minute details on 

 their construction. The furnace should be outside of the 

 house, either at back or end ; the former is preferable, cir- 

 cumstances not always allowing it on the other plan. Dig 

 out the furnace-hole, or what is termed stock-hole, about 

 five feet deep. Let the door of the furnace be in the back 

 wall of the house, thereby having all the heated building 

 inside, that no heat may be lost. The brick-work round 

 the furnace should be nine inches thick, laying the inside 

 with fire-brick. Around the outside leave a vacuum two 

 or three inches wide, to allow the heat to arise from around 

 the furnace into the interior of the house, thereby saving 

 the whole heat of the fuel. The furnace will require to be 

 two and a half feet long, ten inches wide, and one foot 

 high, before the spring of the arch and clear of the bars ; 

 leave one foot for an ash-pit, then lay the bars. They 

 should be sixteen inches long, one inch broad on the upper 

 side, two inches deep, and two-eights broad on the lower 

 side, and, with the door and frame, should be cast iron. 

 Half an inch between each bar will be sufficient. The 

 flue should rise from the furnace by a steep declivity of 

 from twenty inches to two feet, and pass the door of the 

 house, (without a dip,') when it must be elevated above the 

 level of the floor of the house along the front, and at the 

 opposite end of the house must dip to pass the door. The 

 dip must not be lower than the bottom of the flue at the 

 neck of the furnace, and should be of a concave form, 

 (avoiding acute angles.) Lead it along the back to enter 

 the wall over the furnace. When thus taken round the 

 house, the heat will be expanded before it enters the chim- 

 ney. The inside of the flues should be from six to ten 

 inches wide, and eight inches deep ; plaster the bottom of 

 it, but no other part, as plaster is partially a non-conductor. 

 The above description is for burning anthracite coal ; but 

 where wood is to be the fuel, the furnace must be one-half 

 larger. We have been particular in the description of 

 furnace bars, as those generally used are miserable substi- 

 tutes. Circumstances may cause the furnace to be placed 

 at the end or front of the house. In either case the stock 



